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-rw-r--r--Makefile17
-rw-r--r--README21
-rwxr-xr-xplugins/eval312
-rw-r--r--src/siphash.c86
-rw-r--r--src/siphash.h10
-rw-r--r--src/zyklonb.c3320
6 files changed, 3766 insertions, 0 deletions
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..f47959a
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,17 @@
+SHELL = /bin/sh
+CC = clang
+CFLAGS = -ggdb -Wall -Wextra -std=c99
+LDFLAGS = `pkg-config --libs libssl`
+
+.PHONY: all clean
+
+targets = zyklonb
+
+all: $(targets)
+
+clean:
+ rm -f $(targets)
+
+zyklonb: src/zyklonb.c src/siphash.c
+ $(CC) $^ -o $@ $(CFLAGS) $(LDFLAGS)
+
diff --git a/README b/README
new file mode 100644
index 0000000..d00bd27
--- /dev/null
+++ b/README
@@ -0,0 +1,21 @@
+ZyklonB
+=======
+
+`ZyklonB' is an experimental IRC bot, building upon the concept of my other
+VitaminA IRC bot. The main characteristic of these two bots is that they run
+plugins as coprocesses, which allows for enhanced reliability and programming
+language freedom.
+
+While originally intended to be a simple C99 rewrite of the original bot, which
+was written in the GNU dialect of AWK, it fairly quickly became a playground
+where I added everything that seemed nice.
+
+License
+-------
+`ZyklonB' is written by Přemysl Janouch <p.janouch@gmail.com>.
+
+You may use the software under the terms of the ISC license, the text of which
+is included within the package, or, at your option, you may relicense the work
+under the MIT or the Modified BSD License, as listed at the following site:
+
+http://www.gnu.org/licenses/license-list.html
diff --git a/plugins/eval b/plugins/eval
new file mode 100755
index 0000000..97c3349
--- /dev/null
+++ b/plugins/eval
@@ -0,0 +1,312 @@
+#!/usr/bin/awk -f
+#
+# ZyklonB eval plugin, LISP-like expression evaluator
+#
+# Copyright 2013, 2014 Přemysl Janouch. All rights reserved.
+# See the file LICENSE for licensing information.
+#
+
+BEGIN \
+{
+ RS = "\r"
+ ORS = "\r\n"
+ IGNORECASE = 1
+ srand()
+
+ prefix = get_config("prefix")
+
+ print "ZYKLONB register"
+ fflush("")
+
+ # All functions have to be in this particular array
+ min_args["int"] = 1
+ min_args["+"] = 1
+ min_args["-"] = 1
+ min_args["*"] = 1
+ min_args["/"] = 1
+ min_args["%"] = 1
+ min_args["^"] = 1
+ min_args["**"] = 1
+ min_args["exp"] = 1
+ min_args["sin"] = 1
+ min_args["cos"] = 1
+ min_args["atan2"] = 2
+ min_args["log"] = 1
+ min_args["rand"] = 0
+ min_args["sqrt"] = 1
+
+ min_args["pi"] = 0
+ min_args["e"] = 0
+
+ min_args["min"] = 1
+ min_args["max"] = 1
+
+ # Whereas here their presence is only optional
+ max_args["int"] = 1
+ max_args["sin"] = 1
+ max_args["cos"] = 1
+ max_args["atan2"] = 2
+ max_args["log"] = 1
+ max_args["rand"] = 0
+ max_args["sqrt"] = 1
+
+ max_args["pi"] = 0
+ max_args["e"] = 0
+}
+
+{
+ parse($0)
+}
+
+msg_command == "PRIVMSG" \
+{
+ # Context = either channel or user nickname
+ match(msg_prefix, /^[^!]+/)
+ ctx = substr(msg_prefix, RSTART, RLENGTH)
+ if (msg_param[0] ~ /^[#&!+]/)
+ {
+ ctxquote = ctx ": "
+ ctx = msg_param[0]
+ }
+ else
+ ctxquote = ""
+
+
+ if (substr(msg_param[1], 1, length(prefix)) == prefix)
+ {
+ keyword = "eval"
+ text = substr(msg_param[1], 1 + length(prefix))
+ if (match(text, "^" keyword "([^A-Za-z0-9].*|$)"))
+ process_request(substr(text, 1 + length(keyword)))
+ }
+}
+
+{
+ fflush("")
+}
+
+function pmrespond (text)
+{
+ print "PRIVMSG " ctx " :" ctxquote text
+}
+
+function process_request (input, res, x)
+{
+ delete funs
+ delete accumulator
+ delete n_args
+
+ res = ""
+ fun_top = 0
+ funs[0] = ""
+ accumulator[0] = 0
+ n_args[0] = 0
+
+ if (match(input, "^[ \t]*"))
+ input = substr(input, RLENGTH + 1)
+ if (input == "")
+ res = "expression missing"
+
+ while (res == "" && input != "") {
+ if (match(input, "^-?[0-9]+\\.?[0-9]*")) {
+ x = substr(input, RSTART, RLENGTH)
+ input = substr(input, RLENGTH + 1)
+
+ match(input, "^ *")
+ input = substr(input, RLENGTH + 1)
+
+ res = process_argument(x)
+ } else if (match(input, "^[(]([^ ()]+)")) {
+ x = substr(input, RSTART + 1, RLENGTH - 1)
+ input = substr(input, RLENGTH + 1)
+
+ match(input, "^ *")
+ input = substr(input, RLENGTH + 1)
+
+ if (!(x in min_args)) {
+ res = "undefined function '" x "'"
+ } else {
+ fun_top++
+ funs[fun_top] = x
+ accumulator[fun_top] = 636363
+ n_args[fun_top] = 0
+ }
+ } else if (match(input, "^[)] *")) {
+ input = substr(input, RLENGTH + 1)
+ res = process_end()
+ } else
+ res = "invalid input at '" substr(input, 1, 10) "...'"
+ }
+
+ if (res == "") {
+ if (fun_top != 0)
+ res = "unclosed '" funs[fun_top] "'"
+ else if (n_args[0] != 1)
+ res = "internal error, expected one result" \
+ ", got " n_args[0] " instead"
+ }
+
+ if (res == "")
+ pmrespond(accumulator[0])
+ else
+ pmrespond(res)
+}
+
+function process_argument (arg)
+{
+ if (fun_top == 0) {
+ if (n_args[0]++ != 0)
+ return "too many results, I only expect one"
+
+ accumulator[0] = arg
+ return ""
+ }
+
+ fun = funs[fun_top]
+ if (fun in max_args && max_args[fun] <= n_args[fun_top])
+ return "too many operands for " fun
+
+ if (fun == "int") {
+ accumulator[fun_top] = int(arg)
+ } else if (fun == "+") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else
+ accumulator[fun_top] += arg
+ } else if (fun == "-") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else
+ accumulator[fun_top] -= arg
+ } else if (fun == "*") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else
+ accumulator[fun_top] *= arg
+ } else if (fun == "/") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else if (arg == 0)
+ return "division by zero"
+ else
+ accumulator[fun_top] /= arg
+ } else if (fun == "%") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else if (arg == 0)
+ return "division by zero"
+ else
+ accumulator[fun_top] %= arg
+ } else if (fun == "^" || fun == "**" || fun == "exp") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else
+ accumulator[fun_top] ^= arg
+ } else if (fun == "sin") {
+ accumulator[fun_top] = sin(arg)
+ } else if (fun == "cos") {
+ accumulator[fun_top] = cos(arg)
+ } else if (fun == "atan2") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else
+ accumulator[fun_top] = atan2(accumulator[fun_top], arg)
+ } else if (fun == "log") {
+ accumulator[fun_top] = log(arg)
+ } else if (fun == "rand") {
+ # Just for completeness, execution never gets here
+ } else if (fun == "sqrt") {
+ accumulator[fun_top] = sqrt(arg)
+ } else if (fun == "min") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else if (accumulator[fun_top] > arg)
+ accumulator[fun_top] = arg
+ } else if (fun == "max") {
+ if (n_args[fun_top] == 0)
+ accumulator[fun_top] = arg
+ else if (accumulator[fun_top] < arg)
+ accumulator[fun_top] = arg
+ } else
+ return "internal error, unhandled operands for " fun
+
+ n_args[fun_top]++
+ return ""
+}
+
+function process_end ()
+{
+ if (fun_top <= 0)
+ return "extraneous ')'"
+
+ fun = funs[fun_top]
+ if (!(fun in min_args))
+ return "internal error, unhandled ')' for '" fun "'"
+ if (min_args[fun] > n_args[fun_top])
+ return "not enough operands for '" fun "'"
+
+ # There's no 'init' function to do it in
+ if (fun == "rand")
+ accumulator[fun_top] = rand()
+ else if (fun == "pi")
+ accumulator[fun_top] = 3.141592653589793
+ else if (fun == "e")
+ accumulator[fun_top] = 2.718281828459045
+
+ return process_argument(accumulator[fun_top--])
+}
+
+function get_config (key)
+{
+ print "ZYKLONB get_config :" key
+ fflush("")
+
+ getline
+ parse($0)
+ return msg_param[0]
+}
+
+function parse (line, s, n, id, token)
+{
+ s = 1
+ id = 0
+
+ # NAWK only uses the first character of RS
+ if (line ~ /^\n/)
+ line = substr(line, 2)
+
+ msg_prefix = ""
+ msg_command = ""
+ delete msg_param
+
+ n = match(substr(line, s), / |$/)
+ while (n)
+ {
+ token = substr(line, s, n - 1)
+ if (token ~ /^:/)
+ {
+ if (s == 1)
+ msg_prefix = substr(token, 2)
+ else
+ {
+ msg_param[id] = substr(line, s + 1)
+ break
+ }
+ }
+ else if (!msg_command)
+ msg_command = toupper(token)
+ else
+ msg_param[id++] = token
+
+ s = s + n
+ n = index(substr(line, s), " ")
+
+ if (!n)
+ {
+ n = length(substr(line, s)) + 1
+ if (n == 1)
+ break;
+ }
+ }
+}
+
diff --git a/src/siphash.c b/src/siphash.c
new file mode 100644
index 0000000..fa102cc
--- /dev/null
+++ b/src/siphash.c
@@ -0,0 +1,86 @@
+// Code taken from https://github.com/floodyberry/siphash with some edits.
+//
+// To the extent possible under law, the author(s) have dedicated all copyright
+// and related and neighboring rights to this software to the public domain
+// worldwide. This software is distributed without any warranty.
+//
+// You should have received a copy of the CC0 Public Domain Dedication along
+// with this software. If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
+
+#include "siphash.h"
+
+static uint64_t inline
+u8to64_le (const unsigned char *p)
+{
+ return
+ (uint64_t) p[0] |
+ (uint64_t) p[1] << 8 |
+ (uint64_t) p[2] << 16 |
+ (uint64_t) p[3] << 24 |
+ (uint64_t) p[4] << 32 |
+ (uint64_t) p[5] << 40 |
+ (uint64_t) p[6] << 48 |
+ (uint64_t) p[7] << 56 ;
+}
+
+uint64_t
+siphash (const unsigned char key[16], const unsigned char *m, size_t len)
+{
+ uint64_t v0, v1, v2, v3;
+ uint64_t mi, k0, k1;
+ uint64_t last7;
+ size_t i, blocks;
+
+ k0 = u8to64_le (key + 0);
+ k1 = u8to64_le (key + 8);
+ v0 = k0 ^ 0x736f6d6570736575ull;
+ v1 = k1 ^ 0x646f72616e646f6dull;
+ v2 = k0 ^ 0x6c7967656e657261ull;
+ v3 = k1 ^ 0x7465646279746573ull;
+
+ last7 = (uint64_t) (len & 0xff) << 56;
+
+#define ROTL64(a,b) (((a)<<(b))|((a)>>(64-b)))
+
+#define COMPRESS \
+ v0 += v1; v2 += v3; \
+ v1 = ROTL64 (v1,13); v3 = ROTL64 (v3,16); \
+ v1 ^= v0; v3 ^= v2; \
+ v0 = ROTL64 (v0,32); \
+ v2 += v1; v0 += v3; \
+ v1 = ROTL64 (v1,17); v3 = ROTL64 (v3,21); \
+ v1 ^= v2; v3 ^= v0; \
+ v2 = ROTL64(v2,32);
+
+ for (i = 0, blocks = (len & ~7); i < blocks; i += 8) {
+ mi = u8to64_le (m + i);
+ v3 ^= mi;
+ COMPRESS
+ COMPRESS
+ v0 ^= mi;
+ }
+
+ switch (len - blocks)
+ {
+ case 7: last7 |= (uint64_t) m[i + 6] << 48;
+ case 6: last7 |= (uint64_t) m[i + 5] << 40;
+ case 5: last7 |= (uint64_t) m[i + 4] << 32;
+ case 4: last7 |= (uint64_t) m[i + 3] << 24;
+ case 3: last7 |= (uint64_t) m[i + 2] << 16;
+ case 2: last7 |= (uint64_t) m[i + 1] << 8;
+ case 1: last7 |= (uint64_t) m[i + 0] ;
+ default:;
+ };
+ v3 ^= last7;
+ COMPRESS
+ COMPRESS
+ v0 ^= last7;
+ v2 ^= 0xff;
+ COMPRESS
+ COMPRESS
+ COMPRESS
+ COMPRESS
+
+ return v0 ^ v1 ^ v2 ^ v3;
+}
+
diff --git a/src/siphash.h b/src/siphash.h
new file mode 100644
index 0000000..dca7c42
--- /dev/null
+++ b/src/siphash.h
@@ -0,0 +1,10 @@
+#ifndef SIPHASH_H
+#define SIPHASH_H
+
+#include <stdint.h>
+#include <stdlib.h>
+
+uint64_t siphash (const unsigned char key[16],
+ const unsigned char *m, size_t len);
+
+#endif // SIPHASH_H
diff --git a/src/zyklonb.c b/src/zyklonb.c
new file mode 100644
index 0000000..a182d17
--- /dev/null
+++ b/src/zyklonb.c
@@ -0,0 +1,3320 @@
+/*
+ * zyklonb.c: the experimental IRC bot
+ *
+ * Copyright (c) 2014, Přemysl Janouch <p.janouch@gmail.com>
+ * All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
+ * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
+ * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#define _POSIX_C_SOURCE 199309L
+#define _XOPEN_SOURCE 500
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <ctype.h>
+
+#include <unistd.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <signal.h>
+#include <strings.h>
+#include <regex.h>
+#include <libgen.h>
+
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <netdb.h>
+
+#ifndef NI_MAXHOST
+#define NI_MAXHOST 1025
+#endif // ! NI_MAXHOST
+
+#include <getopt.h>
+#include <openssl/ssl.h>
+#include <openssl/err.h>
+#include "siphash.h"
+
+#define PROGRAM_NAME "ZyklonB"
+#define PROGRAM_VERSION "alpha"
+
+extern char **environ;
+
+#if defined __GNUC__
+#define ATTRIBUTE_PRINTF(x, y) __attribute__ ((format (printf, x, y)))
+#else // ! __GNUC__
+#define ATTRIBUTE_PRINTF(x, y)
+#endif // ! __GNUC__
+
+#if defined __GNUC__ && __GNUC__ >= 4
+#define ATTRIBUTE_SENTINEL __attribute__ ((sentinel))
+#else // ! __GNUC__ || __GNUC__ < 4
+#define ATTRIBUTE_SENTINEL
+#endif // ! __GNUC__ || __GNUC__ < 4
+
+#define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0]))
+
+#define BLOCK_START do {
+#define BLOCK_END } while (0)
+
+// --- Utilities ---------------------------------------------------------------
+
+static void
+print_message (FILE *stream, const char *type, const char *fmt, ...)
+ ATTRIBUTE_PRINTF (3, 4);
+
+static void
+print_message (FILE *stream, const char *type, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start (ap, fmt);
+ fprintf (stream, "%s ", type);
+ vfprintf (stream, fmt, ap);
+ fputs ("\n", stream);
+ va_end (ap);
+}
+
+#define print_fatal(...) print_message (stderr, "fatal:", __VA_ARGS__)
+#define print_error(...) print_message (stderr, "error:", __VA_ARGS__)
+#define print_warning(...) print_message (stderr, "warning:", __VA_ARGS__)
+#define print_status(...) print_message (stdout, "--", __VA_ARGS__)
+
+// --- Debugging and assertions ------------------------------------------------
+
+// We should check everything that may possibly fail with at least a soft
+// assertion, so that any causes for problems don't slip us by silently.
+//
+// `g_soft_asserts_are_deadly' may be useful while running inside a debugger.
+
+static bool g_debug_mode; ///< Debug messages are printed
+static bool g_soft_asserts_are_deadly; ///< soft_assert() aborts as well
+
+#define print_debug(...) \
+ BLOCK_START \
+ if (g_debug_mode) \
+ print_message (stderr, "debug:", __VA_ARGS__); \
+ BLOCK_END
+
+static void
+assertion_failure_handler (bool is_fatal, const char *file, int line,
+ const char *function, const char *condition)
+{
+ if (is_fatal)
+ {
+ print_fatal ("assertion failed [%s:%d in function %s]: %s",
+ file, line, function, condition);
+ abort ();
+ }
+ else
+ print_debug ("assertion failed [%s:%d in function %s]: %s",
+ file, line, function, condition);
+}
+
+#define soft_assert(condition) \
+ ((condition) ? true : \
+ (assertion_failure_handler (g_soft_asserts_are_deadly, \
+ __FILE__, __LINE__, __func__, #condition), false))
+
+#define hard_assert(condition) \
+ ((condition) ? (void) 0 : \
+ assertion_failure_handler (true, \
+ __FILE__, __LINE__, __func__, #condition))
+
+// --- Safe memory management --------------------------------------------------
+
+// When a memory allocation fails and we need the memory, we're usually pretty
+// much fucked. Use the non-prefixed versions when there's a legitimate
+// worry that an unrealistic amount of memory may be requested for allocation.
+
+// XXX: it's not a good idea to use print_message() as it may want to allocate
+// further memory for printf() and the output streams. That may fail.
+
+static void *
+xmalloc (size_t n)
+{
+ void *p = malloc (n);
+ if (!p)
+ {
+ print_fatal ("malloc: %s", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+ return p;
+}
+
+static void *
+xcalloc (size_t n, size_t m)
+{
+ void *p = calloc (n, m);
+ if (!p && n && m)
+ {
+ print_fatal ("calloc: %s", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+ return p;
+}
+
+static void *
+xrealloc (void *o, size_t n)
+{
+ void *p = realloc (o, n);
+ if (!p && n)
+ {
+ print_fatal ("realloc: %s", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+ return p;
+}
+
+static void *
+xreallocarray (void *o, size_t n, size_t m)
+{
+ if (m && n > SIZE_MAX / m)
+ {
+ errno = ENOMEM;
+ print_fatal ("reallocarray: %s", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+ return xrealloc (o, n * m);
+}
+
+static char *
+xstrdup (const char *s)
+{
+ return strcpy (xmalloc (strlen (s) + 1), s);
+}
+
+static char *
+xstrndup (const char *s, size_t n)
+{
+ size_t size = strlen (s);
+ if (n > size)
+ n = size;
+
+ char *copy = xmalloc (n + 1);
+ memcpy (copy, s, n);
+ copy[n] = '\0';
+ return copy;
+}
+
+// --- Double-linked list helpers ----------------------------------------------
+
+// The links of the list need to have the members `prev' and `next'.
+
+#define LIST_PREPEND(head, link) \
+ BLOCK_START \
+ (link)->prev = NULL; \
+ (link)->next = (head); \
+ if ((link)->next) \
+ (link)->next->prev = (link); \
+ (head) = (link); \
+ BLOCK_END
+
+#define LIST_UNLINK(head, link) \
+ BLOCK_START \
+ if ((link)->prev) \
+ (link)->prev->next = (link)->next; \
+ else \
+ (head) = (link)->next; \
+ if ((link)->next) \
+ (link)->next->prev = (link)->prev; \
+ BLOCK_END
+
+// --- Dynamically allocated string array --------------------------------------
+
+struct str_vector
+{
+ char **vector;
+ size_t len;
+ size_t alloc;
+};
+
+static void
+str_vector_init (struct str_vector *self)
+{
+ self->alloc = 4;
+ self->len = 0;
+ self->vector = xcalloc (sizeof *self->vector, self->alloc);
+}
+
+static void
+str_vector_free (struct str_vector *self)
+{
+ unsigned i;
+ for (i = 0; i < self->len; i++)
+ free (self->vector[i]);
+
+ free (self->vector);
+ self->vector = NULL;
+}
+
+static void
+str_vector_add_owned (struct str_vector *self, char *s)
+{
+ self->vector[self->len] = s;
+ if (++self->len >= self->alloc)
+ self->vector = xreallocarray (self->vector,
+ sizeof *self->vector, (self->alloc <<= 1));
+ self->vector[self->len] = NULL;
+}
+
+static void
+str_vector_add (struct str_vector *self, const char *s)
+{
+ str_vector_add_owned (self, xstrdup (s));
+}
+
+static void
+str_vector_add_args (struct str_vector *self, const char *s, ...)
+ ATTRIBUTE_SENTINEL;
+
+static void
+str_vector_add_args (struct str_vector *self, const char *s, ...)
+{
+ va_list ap;
+
+ va_start (ap, s);
+ while (s)
+ {
+ str_vector_add (self, s);
+ s = va_arg (ap, const char *);
+ }
+ va_end (ap);
+}
+
+static void
+str_vector_add_vector (struct str_vector *self, char **vector)
+{
+ while (*vector)
+ str_vector_add (self, *vector++);
+}
+
+static void
+str_vector_remove (struct str_vector *self, size_t i)
+{
+ hard_assert (i < self->len);
+ free (self->vector[i]);
+ memmove (self->vector + i, self->vector + i + 1,
+ (self->len-- - i) * sizeof *self->vector);
+}
+
+// --- Dynamically allocated strings -------------------------------------------
+
+// Basically a string builder to abstract away manual memory management.
+
+struct str
+{
+ char *str; ///< String data, null terminated
+ size_t alloc; ///< How many bytes are allocated
+ size_t len; ///< How long the string actually is
+};
+
+/// We don't care about allocations that are way too large for the content, as
+/// long as the allocation is below the given threshold. (Trivial heuristics.)
+#define STR_SHRINK_THRESHOLD (1 << 20)
+
+static void
+str_init (struct str *self)
+{
+ self->alloc = 16;
+ self->len = 0;
+ self->str = strcpy (xmalloc (self->alloc), "");
+}
+
+static void
+str_free (struct str *self)
+{
+ free (self->str);
+ self->str = NULL;
+ self->alloc = 0;
+ self->len = 0;
+}
+
+static void
+str_reset (struct str *self)
+{
+ str_free (self);
+ str_init (self);
+}
+
+static char *
+str_steal (struct str *self)
+{
+ char *str = self->str;
+ self->str = NULL;
+ str_free (self);
+ return str;
+}
+
+static void
+str_ensure_space (struct str *self, size_t n)
+{
+ // We allocate at least one more byte for the terminating null character
+ size_t new_alloc = self->alloc;
+ while (new_alloc <= self->len + n)
+ new_alloc <<= 1;
+ if (new_alloc != self->alloc)
+ self->str = xrealloc (self->str, (self->alloc = new_alloc));
+}
+
+static void
+str_append_data (struct str *self, const char *data, size_t n)
+{
+ str_ensure_space (self, n);
+ memcpy (self->str + self->len, data, n);
+ self->len += n;
+ self->str[self->len] = '\0';
+}
+
+static void
+str_append_c (struct str *self, char c)
+{
+ str_append_data (self, &c, 1);
+}
+
+static void
+str_append (struct str *self, const char *s)
+{
+ str_append_data (self, s, strlen (s));
+}
+
+static void
+str_append_str (struct str *self, const struct str *another)
+{
+ str_append_data (self, another->str, another->len);
+}
+
+static int
+str_append_vprintf (struct str *self, const char *fmt, va_list va)
+{
+ va_list ap;
+ int size;
+
+ va_copy (ap, va);
+ size = vsnprintf (NULL, 0, fmt, ap);
+ va_end (ap);
+
+ if (size < 0)
+ return -1;
+
+ va_copy (ap, va);
+ str_ensure_space (self, size);
+ size = vsnprintf (self->str + self->len, self->alloc - self->len, fmt, ap);
+ va_end (ap);
+
+ if (size > 0)
+ self->len += size;
+
+ return size;
+}
+
+static int
+str_append_printf (struct str *self, const char *fmt, ...)
+ ATTRIBUTE_PRINTF (2, 3);
+
+static int
+str_append_printf (struct str *self, const char *fmt, ...)
+{
+ va_list ap;
+
+ va_start (ap, fmt);
+ int size = str_append_vprintf (self, fmt, ap);
+ va_end (ap);
+ return size;
+}
+
+static void
+str_remove_slice (struct str *self, size_t start, size_t length)
+{
+ size_t end = start + length;
+ hard_assert (end <= self->len);
+ memmove (self->str + start, self->str + end, self->len - end);
+ self->str[self->len -= length] = '\0';
+
+ // Shrink the string if the allocation becomes way too large
+ if (self->alloc >= STR_SHRINK_THRESHOLD && self->len < (self->alloc >> 2))
+ self->str = xrealloc (self->str, self->alloc >>= 2);
+}
+
+// --- Errors ------------------------------------------------------------------
+
+// Error reporting utilities. Inspired by GError, only much simpler.
+
+struct error
+{
+ size_t domain; ///< The domain of the error
+ int id; ///< The concrete error ID
+ char *message; ///< Textual description of the event
+};
+
+static size_t
+error_resolve_domain (size_t *tag)
+{
+ // This method is fairly sensitive to the order in which resolution
+ // requests come in, does not provide a good way of decoding the number
+ // back to a meaningful identifier, and may not play all too well with
+ // dynamic libraries when a module is e.g. statically linked into multiple
+ // libraries, but it's fast, simple, and more than enough for our purposes.
+ static size_t domain_counter;
+
+ if (!*tag)
+ *tag = ++domain_counter;
+ return *tag;
+}
+
+static void
+error_set (struct error **e, size_t domain, int id,
+ const char *message, ...) ATTRIBUTE_PRINTF (4, 5);
+
+static void
+error_set (struct error **e, size_t domain, int id,
+ const char *message, ...)
+{
+ if (!e)
+ return;
+
+ va_list ap;
+ va_start (ap, message);
+ int size = snprintf (NULL, 0, message, ap);
+ va_end (ap);
+
+ hard_assert (size >= 0);
+
+ struct error *tmp = xmalloc (sizeof *tmp);
+ tmp->domain = domain;
+ tmp->id = id;
+ tmp->message = xmalloc (size + 1);
+
+ va_start (ap, message);
+ size = snprintf (tmp->message, size + 1, message, ap);
+ va_end (ap);
+
+ hard_assert (size >= 0);
+
+ soft_assert (*e == NULL);
+ *e = tmp;
+}
+
+static void
+error_free (struct error *e)
+{
+ free (e->message);
+ free (e);
+}
+
+static void
+error_propagate (struct error **destination, struct error *source)
+{
+ if (!destination)
+ {
+ error_free (source);
+ return;
+ }
+
+ soft_assert (*destination == NULL);
+ *destination = source;
+}
+
+// --- String hash map ---------------------------------------------------------
+
+// The most basic <string, managed pointer> map (or associative array).
+
+struct str_map_link
+{
+ struct str_map_link *next; ///< The next link in a chain
+ struct str_map_link *prev; ///< The previous link in a chain
+
+ void *data; ///< Payload
+ size_t key_length; ///< Length of the key without '\0'
+ char key[]; ///< The key for this link
+};
+
+struct str_map
+{
+ struct str_map_link **map; ///< The hash table data itself
+ size_t alloc; ///< Number of allocated entries
+ size_t len; ///< Number of entries in the table
+ void (*free) (void *); ///< Callback to destruct the payload
+};
+
+#define STR_MAP_MIN_ALLOC 16
+
+typedef void (*str_map_free_func) (void *);
+
+static void
+str_map_init (struct str_map *self)
+{
+ self->alloc = STR_MAP_MIN_ALLOC;
+ self->len = 0;
+ self->free = NULL;
+ self->map = xcalloc (self->alloc, sizeof *self->map);
+}
+
+static void
+str_map_free (struct str_map *self)
+{
+ struct str_map_link **iter, **end = self->map + self->alloc;
+ struct str_map_link *link, *tmp;
+
+ for (iter = self->map; iter < end; iter++)
+ for (link = *iter; link; link = tmp)
+ {
+ tmp = link->next;
+ if (self->free)
+ self->free (link->data);
+ free (link);
+ }
+
+ free (self->map);
+ self->map = NULL;
+}
+
+static uint64_t
+str_map_hash (const char *s, size_t len)
+{
+ static unsigned char key[16] = "SipHash 2-4 key!";
+ return siphash (key, (const void *) s, len);
+}
+
+static uint64_t
+str_map_pos (struct str_map *self, const char *s)
+{
+ size_t mask = self->alloc - 1;
+ return str_map_hash (s, strlen (s)) & mask;
+}
+
+static uint64_t
+str_map_link_hash (struct str_map_link *self)
+{
+ return str_map_hash (self->key, self->key_length);
+}
+
+static void
+str_map_resize (struct str_map *self, size_t new_size)
+{
+ struct str_map_link **old_map = self->map;
+ size_t i, old_size = self->alloc;
+
+ // Only powers of two, so that we don't need to compute the modulo
+ hard_assert ((new_size & (new_size - 1)) == 0);
+ size_t mask = new_size - 1;
+
+ self->alloc = new_size;
+ self->map = xcalloc (self->alloc, sizeof *self->map);
+ for (i = 0; i < old_size; i++)
+ {
+ struct str_map_link *iter = old_map[i], *next_iter;
+ while (iter)
+ {
+ next_iter = iter->next;
+ uint64_t pos = str_map_link_hash (iter) & mask;
+ LIST_PREPEND (self->map[pos], iter);
+ iter = next_iter;
+ }
+ }
+
+ free (old_map);
+}
+
+static void
+str_map_set (struct str_map *self, const char *key, void *value)
+{
+ uint64_t pos = str_map_pos (self, key);
+ struct str_map_link *iter = self->map[pos];
+ for (; iter; iter = iter->next)
+ {
+ if (strcmp (key, iter->key))
+ continue;
+
+ // Storing the same data doesn't destroy it
+ if (self->free && value != iter->data)
+ self->free (iter->data);
+
+ if (value)
+ {
+ iter->data = value;
+ return;
+ }
+
+ LIST_UNLINK (self->map[pos], iter);
+ free (iter);
+ self->len--;
+
+ // The array should be at least 1/4 full
+ if (self->alloc >= (STR_MAP_MIN_ALLOC << 2)
+ && self->len < (self->alloc >> 2))
+ str_map_resize (self, self->alloc >> 2);
+ return;
+ }
+
+ if (!value)
+ return;
+
+ if (self->len >= self->alloc)
+ {
+ str_map_resize (self, self->alloc << 1);
+ pos = str_map_pos (self, key);
+ }
+
+ // Link in a new element for the given <key, value> pair
+ size_t key_length = strlen (key);
+ struct str_map_link *link = xmalloc (sizeof *link + key_length + 1);
+ link->data = value;
+ link->key_length = key_length;
+ memcpy (link->key, key, key_length + 1);
+
+ LIST_PREPEND (self->map[pos], link);
+ self->len++;
+}
+
+static void *
+str_map_find (struct str_map *self, const char *key)
+{
+ struct str_map_link *iter = self->map[str_map_pos (self, key)];
+ for (; iter; iter = iter->next)
+ if (!strcmp (key, (char *) iter + sizeof *iter))
+ return iter->data;
+ return NULL;
+}
+
+// --- File descriptor utilities -----------------------------------------------
+
+static void
+set_cloexec (int fd)
+{
+ soft_assert (fcntl (fd, F_SETFD, fcntl (fd, F_GETFD) | FD_CLOEXEC) != -1);
+}
+
+static bool
+set_blocking (int fd, bool blocking)
+{
+ int flags = fcntl (fd, F_GETFL);
+ hard_assert (flags != -1);
+
+ bool prev = !(flags & O_NONBLOCK);
+ if (blocking)
+ flags &= ~O_NONBLOCK;
+ else
+ flags |= O_NONBLOCK;
+
+ hard_assert (fcntl (fd, F_SETFL, flags) != -1);
+ return prev;
+}
+
+static void
+xclose (int fd)
+{
+ while (close (fd) == -1)
+ if (!soft_assert (errno == EINTR))
+ break;
+}
+
+// --- Polling -----------------------------------------------------------------
+
+// Basically the poor man's GMainLoop/libev/libuv. It might make some sense
+// to instead use those tested and proven libraries but we don't need much
+// and it's interesting to implement.
+
+// At the moment the FD's are stored in an unsorted array. This is not ideal
+// complexity-wise but I don't think I have much of a choice with poll(),
+// and neither with epoll for that matter.
+//
+// unsorted array sorted array
+// search O(n) O(log n) [O(log log n)]
+// insert by fd O(n) O(n)
+// delete by fd O(n) O(n)
+//
+// Insertion in the unsorted array can be reduced to O(1) if I maintain a
+// bitmap of present FD's but that's still not a huge win.
+//
+// I don't expect this to be much of an issue, as there are typically not going
+// to be that many FD's to watch, and the linear approach is cache-friendly.
+
+typedef void (*poller_dispatcher_func) (const struct pollfd *, void *);
+
+#define POLLER_MIN_ALLOC 16
+
+#ifdef __linux__
+
+// I don't really need this, I've basically implemented this just because I can.
+
+#include <sys/epoll.h>
+
+struct poller_info
+{
+ int fd; ///< Our file descriptor
+ uint32_t events; ///< The events we registered
+ poller_dispatcher_func dispatcher; ///< Event dispatcher
+ void *user_data; ///< User data
+};
+
+struct poller
+{
+ int epoll_fd; ///< The epoll FD
+ struct poller_info **info; ///< Information associated with each FD
+ struct epoll_event *revents; ///< Output array for epoll_wait()
+ size_t len; ///< Number of polled descriptors
+ size_t alloc; ///< Number of entries allocated
+
+ /// Index of the element in `revents' that's currently being dispatched,
+ /// or -1 if we're not dispatching at the moment.
+ int dispatch_iterator;
+
+ /// The total number of entries stored in `revents' by epoll_wait().
+ int dispatch_total;
+};
+
+static void
+poller_init (struct poller *self)
+{
+ self->epoll_fd = epoll_create (POLLER_MIN_ALLOC);
+ hard_assert (self->epoll_fd != -1);
+ set_cloexec (self->epoll_fd);
+
+ self->len = 0;
+ self->alloc = POLLER_MIN_ALLOC;
+ self->info = xcalloc (self->alloc, sizeof *self->info);
+ self->revents = xcalloc (self->alloc, sizeof *self->revents);
+
+ self->dispatch_iterator = -1;
+ self->dispatch_total = 0;
+}
+
+static void
+poller_free (struct poller *self)
+{
+ for (size_t i = 0; i < self->len; i++)
+ {
+ struct poller_info *info = self->info[i];
+ hard_assert (epoll_ctl (self->epoll_fd,
+ EPOLL_CTL_DEL, info->fd, (void *) "") != -1);
+ free (info);
+ }
+
+ xclose (self->epoll_fd);
+ free (self->info);
+ free (self->revents);
+}
+
+static ssize_t
+poller_find_by_fd (struct poller *self, int fd)
+{
+ for (size_t i = 0; i < self->len; i++)
+ if (self->info[i]->fd == fd)
+ return i;
+ return -1;
+}
+
+static void
+poller_ensure_space (struct poller *self)
+{
+ if (self->len < self->alloc)
+ return;
+
+ self->alloc <<= 1;
+ self->revents = xreallocarray
+ (self->revents, sizeof *self->revents, self->alloc);
+ self->info = xreallocarray
+ (self->info, sizeof *self->info, self->alloc);
+}
+
+static int
+poller_epoll_to_poll_events (int events)
+{
+ int result = 0;
+ if (events & EPOLLIN) result |= POLLIN;
+ if (events & EPOLLOUT) result |= POLLOUT;
+ if (events & EPOLLERR) result |= POLLERR;
+ if (events & EPOLLHUP) result |= POLLHUP;
+ if (events & EPOLLPRI) result |= POLLPRI;
+ return result;
+}
+
+static uint32_t
+poller_poll_to_epoll_events (uint32_t events)
+{
+ uint32_t result = 0;
+ if (events & POLLIN) result |= EPOLLIN;
+ if (events & POLLOUT) result |= EPOLLOUT;
+ if (events & POLLERR) result |= EPOLLERR;
+ if (events & POLLHUP) result |= EPOLLHUP;
+ if (events & POLLPRI) result |= EPOLLPRI;
+ return result;
+}
+
+static void
+poller_set (struct poller *self, int fd, short int events,
+ poller_dispatcher_func dispatcher, void *data)
+{
+ ssize_t index = poller_find_by_fd (self, fd);
+ bool modifying = true;
+ if (index == -1)
+ {
+ poller_ensure_space (self);
+ self->info[index = self->len++] = xcalloc (1, sizeof **self->info);
+ modifying = false;
+ }
+
+ struct poller_info *info = self->info[index];
+ info->fd = fd;
+ info->dispatcher = dispatcher;
+ info->user_data = data;
+
+ struct epoll_event event;
+ event.events = poller_poll_to_epoll_events (events);
+ event.data.ptr = info;
+ hard_assert (epoll_ctl (self->epoll_fd,
+ modifying ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &event) != -1);
+}
+
+static void
+poller_remove_from_dispatch (struct poller *self,
+ const struct poller_info *info)
+{
+ if (self->dispatch_iterator == -1)
+ return;
+
+ int i;
+ for (i = self->dispatch_iterator; i < self->dispatch_total; i++)
+ if (self->revents[i].data.ptr == info)
+ break;
+ if (i == self->dispatch_total)
+ return;
+
+ if (i != --self->dispatch_total)
+ self->revents[i] = self->revents[self->dispatch_total];
+
+ // We've removed the element we're currently processing; go back one entry
+ // so that we don't skip the one we might have replaced it with.
+ if (i == self->dispatch_iterator)
+ self->dispatch_iterator--;
+}
+
+static void
+poller_remove_at_index (struct poller *self, size_t index)
+{
+ hard_assert (index < self->len);
+ struct poller_info *info = self->info[index];
+
+ poller_remove_from_dispatch (self, info);
+ hard_assert (epoll_ctl (self->epoll_fd,
+ EPOLL_CTL_DEL, info->fd, (void *) "") != -1);
+
+ free (info);
+ if (index != --self->len)
+ self->info[index] = self->info[self->len];
+}
+
+static void
+poller_run (struct poller *self)
+{
+ // Not reentrant
+ hard_assert (self->dispatch_iterator == -1);
+
+ int n_fds;
+ do
+ n_fds = epoll_wait (self->epoll_fd, self->revents, self->len, -1);
+ while (n_fds == -1 && errno == EINTR);
+
+ if (n_fds == -1)
+ {
+ print_fatal ("%s: %s", "epoll", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+
+ for (int i = 0; i < n_fds; i++)
+ {
+ struct epoll_event *revents = self->revents + i;
+ struct poller_info *info = revents->data.ptr;
+
+ struct pollfd pfd;
+ pfd.fd = info->fd;
+ pfd.revents = poller_epoll_to_poll_events (revents->events);
+ pfd.events = poller_epoll_to_poll_events (info->events);
+
+ self->dispatch_iterator = i;
+ self->dispatch_total = n_fds;
+
+ info->dispatcher (&pfd, info->user_data);
+
+ i = self->dispatch_iterator;
+ n_fds = self->dispatch_total;
+ }
+
+ self->dispatch_iterator = -1;
+ self->dispatch_total = 0;
+}
+
+#else // !__linux__
+
+struct poller_info
+{
+ poller_dispatcher_func dispatcher; ///< Event dispatcher
+ void *user_data; ///< User data
+};
+
+struct poller
+{
+ struct pollfd *fds; ///< Polled descriptors
+ struct poller_info *fds_info; ///< Additional information for each FD
+ size_t len; ///< Number of polled descriptors
+ size_t alloc; ///< Number of entries allocated
+
+ int dispatch_index; ///< The currently dispatched FD or -1
+};
+
+static void
+poller_init (struct poller *self)
+{
+ self->alloc = POLLER_MIN_ALLOC;
+ self->len = 0;
+ self->fds = xcalloc (self->alloc, sizeof *self->fds);
+ self->fds_info = xcalloc (self->alloc, sizeof *self->fds_info);
+ self->dispatch_index = -1;
+}
+
+static void
+poller_free (struct poller *self)
+{
+ free (self->fds);
+ free (self->fds_info);
+}
+
+static ssize_t
+poller_find_by_fd (struct poller *self, int fd)
+{
+ for (size_t i = 0; i < self->len; i++)
+ if (self->fds[i].fd == fd)
+ return i;
+ return -1;
+}
+
+static void
+poller_ensure_space (struct poller *self)
+{
+ if (self->len < self->alloc)
+ return;
+
+ self->alloc <<= 1;
+ self->fds = xreallocarray (self->fds, sizeof *self->fds, self->alloc);
+ self->fds_info = xreallocarray
+ (self->fds_info, sizeof *self->fds_info, self->alloc);
+}
+
+static void
+poller_set (struct poller *self, int fd, short int events,
+ poller_dispatcher_func dispatcher, void *data)
+{
+ ssize_t index = poller_find_by_fd (self, fd);
+ if (index == -1)
+ {
+ poller_ensure_space (self);
+ index = self->len++;
+ }
+
+ struct pollfd *new_entry = self->fds + index;
+ memset (new_entry, 0, sizeof *new_entry);
+ new_entry->fd = fd;
+ new_entry->events = events;
+
+ self->fds_info[self->len] = (struct poller_info) { dispatcher, data };
+}
+
+static void
+poller_remove_at_index (struct poller *self, size_t index)
+{
+ hard_assert (index < self->len);
+ if (index == --self->len)
+ return;
+
+ // Make sure that we don't disrupt the dispatch loop; kind of crude
+ if ((int) index < self->dispatch_index)
+ {
+ memmove (self->fds + index, self->fds + index + 1,
+ (self->len - index) * sizeof *self->fds);
+ memmove (self->fds_info + index, self->fds_info + index + 1,
+ (self->len - index) * sizeof *self->fds_info);
+ }
+ else
+ {
+ self->fds[index] = self->fds[self->len];
+ self->fds_info[index] = self->fds_info[self->len];
+ }
+
+ if ((int) index <= self->dispatch_index)
+ self->dispatch_index--;
+}
+
+static void
+poller_run (struct poller *self)
+{
+ // Not reentrant
+ hard_assert (self->dispatch_index == -1);
+
+ int result;
+ do
+ result = poll (self->fds, self->len, -1);
+ while (result == -1 && errno == EINTR);
+
+ if (result == -1)
+ {
+ print_fatal ("%s: %s", "poll", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+
+ for (int i = 0; i < (int) self->len; i++)
+ {
+ struct pollfd pfd = self->fds[i];
+ if (!pfd.revents)
+ continue;
+
+ struct poller_info *info = self->fds_info + i;
+ self->dispatch_index = i;
+ info->dispatcher (&pfd, info->user_data);
+ i = self->dispatch_index;
+ }
+
+ self->dispatch_index = -1;
+}
+
+#endif // !__linux__
+
+// --- Utilities ---------------------------------------------------------------
+
+static void
+split_str_ignore_empty (const char *s, char delimiter, struct str_vector *out)
+{
+ const char *begin = s, *end;
+
+ while ((end = strchr (begin, delimiter)))
+ {
+ if (begin != end)
+ str_vector_add_owned (out, xstrndup (begin, end - begin));
+ begin = ++end;
+ }
+
+ if (*begin)
+ str_vector_add (out, begin);
+}
+
+static char *
+strip_str_in_place (char *s, const char *stripped_chars)
+{
+ char *end = s + strlen (s);
+ while (end > s && strchr (stripped_chars, end[-1]))
+ *--end = '\0';
+
+ char *start = s + strspn (s, stripped_chars);
+ if (start > s)
+ memmove (s, start, end - start + 1);
+ return s;
+}
+
+static bool
+str_append_env_path (struct str *output, const char *var, bool only_absolute)
+{
+ const char *value = getenv (var);
+
+ if (!value || (only_absolute && *value != '/'))
+ return false;
+
+ str_append (output, value);
+ return true;
+}
+
+static void
+get_xdg_home_dir (struct str *output, const char *var, const char *def)
+{
+ str_reset (output);
+ if (!str_append_env_path (output, var, true))
+ {
+ str_append_env_path (output, "HOME", false);
+ str_append_c (output, '/');
+ str_append (output, def);
+ }
+}
+
+static size_t io_error_domain_tag;
+#define IO_ERROR (error_resolve_domain (&io_error_domain_tag))
+
+enum
+{
+ IO_ERROR_FAILED
+};
+
+static bool
+ensure_directory_existence (const char *path, struct error **e)
+{
+ struct stat st;
+
+ if (stat (path, &st))
+ {
+ if (mkdir (path, S_IRWXU | S_IRWXG | S_IRWXO))
+ {
+ error_set (e, IO_ERROR, IO_ERROR_FAILED,
+ "cannot create directory `%s': %s",
+ path, strerror (errno));
+ return false;
+ }
+ }
+ else if (!S_ISDIR (st.st_mode))
+ {
+ error_set (e, IO_ERROR, IO_ERROR_FAILED,
+ "cannot create directory `%s': %s",
+ path, "file exists but is not a directory");
+ return false;
+ }
+ return true;
+}
+
+static bool
+mkdir_with_parents (char *path, struct error **e)
+{
+ char *p = path;
+
+ // XXX: This is prone to the TOCTTOU problem. The solution would be to
+ // rewrite the function using the {mkdir,fstat}at() functions from
+ // POSIX.1-2008, ideally returning a file descriptor to the open
+ // directory, with the current code as a fallback. Or to use chdir().
+ while ((p = strchr (p + 1, '/')))
+ {
+ *p = '\0';
+ bool success = ensure_directory_existence (path, e);
+ *p = '/';
+
+ if (!success)
+ return false;
+ }
+
+ return ensure_directory_existence (path, e);
+}
+
+static bool
+set_boolean_if_valid (bool *out, const char *s)
+{
+ if (!strcasecmp (s, "yes")) *out = true;
+ else if (!strcasecmp (s, "no")) *out = false;
+ else if (!strcasecmp (s, "on")) *out = true;
+ else if (!strcasecmp (s, "off")) *out = false;
+ else if (!strcasecmp (s, "true")) *out = true;
+ else if (!strcasecmp (s, "false")) *out = false;
+ else return false;
+
+ return true;
+}
+
+static void
+regerror_to_str (int code, const regex_t *preg, struct str *out)
+{
+ size_t required = regerror (code, preg, NULL, 0);
+ str_ensure_space (out, required);
+ out->len += regerror (code, preg,
+ out->str + out->len, out->alloc - out->len) - 1;
+}
+
+static size_t regex_error_domain_tag;
+#define REGEX_ERROR (error_resolve_domain (&regex_error_domain_tag))
+
+enum
+{
+ REGEX_ERROR_COMPILATION_FAILED
+};
+
+static bool
+regex_match (const char *regex, const char *s, struct error **e)
+{
+ regex_t re;
+ int err = regcomp (&re, regex, REG_EXTENDED | REG_NOSUB);
+ if (err)
+ {
+ struct str desc;
+
+ str_init (&desc);
+ regerror_to_str (err, &re, &desc);
+ error_set (e, REGEX_ERROR, REGEX_ERROR_COMPILATION_FAILED,
+ "failed to compile regular expression: %s", desc.str);
+ str_free (&desc);
+ return false;
+ }
+
+ bool result = regexec (&re, s, 0, NULL, 0) != REG_NOMATCH;
+ regfree (&re);
+ return result;
+}
+
+static bool
+read_line (FILE *fp, struct str *s)
+{
+ int c;
+ bool at_end = true;
+
+ str_reset (s);
+ while ((c = fgetc (fp)) != EOF)
+ {
+ at_end = false;
+ if (c == '\r')
+ continue;
+ if (c == '\n')
+ break;
+ str_append_c (s, c);
+ }
+
+ return !at_end;
+}
+
+// --- IRC utilities -----------------------------------------------------------
+
+struct irc_message
+{
+ char *prefix;
+ char *command;
+ struct str_vector params;
+};
+
+static void
+irc_parse_message (struct irc_message *msg, const char *line)
+{
+ msg->prefix = NULL;
+ msg->command = NULL;
+ str_vector_init (&msg->params);
+
+ // Prefix
+ if (*line == ':')
+ {
+ size_t prefix_len = strcspn (++line, " ");
+ msg->prefix = xstrndup (line, prefix_len);
+ line += prefix_len;
+ }
+
+ // Command name
+ {
+ while (*line == ' ')
+ line++;
+
+ size_t cmd_len = strcspn (line, " ");
+ msg->command = xstrndup (line, cmd_len);
+ line += cmd_len;
+ }
+
+ // Arguments
+ while (true)
+ {
+ while (*line == ' ')
+ line++;
+
+ if (*line == ':')
+ {
+ str_vector_add (&msg->params, ++line);
+ break;
+ }
+
+ size_t param_len = strcspn (line, " ");
+ if (!param_len)
+ break;
+
+ str_vector_add_owned (&msg->params, xstrndup (line, param_len));
+ line += param_len;
+ }
+}
+
+static void
+irc_free_message (struct irc_message *msg)
+{
+ free (msg->prefix);
+ free (msg->command);
+ str_vector_free (&msg->params);
+}
+
+static void
+irc_process_buffer (struct str *buf,
+ void (*callback)(const struct irc_message *, const char *, void *),
+ void *user_data)
+{
+ char *start = buf->str;
+ char *end = start + buf->len;
+
+ for (char *p = start; p + 1 < end; p++)
+ {
+ // Split the input on newlines
+ if (p[0] != '\r' || p[1] != '\n')
+ continue;
+
+ *p = 0;
+
+ struct irc_message msg;
+ irc_parse_message (&msg, start);
+ callback (&msg, start, user_data);
+ irc_free_message (&msg);
+
+ start = p + 2;
+ }
+
+ str_remove_slice (buf, 0, start - buf->str);
+}
+
+// --- Configuration -----------------------------------------------------------
+
+// The keys are stripped of surrounding whitespace, the values are not.
+
+static size_t config_error_domain_tag;
+#define CONFIG_ERROR (error_resolve_domain (&config_error_domain_tag))
+
+enum
+{
+ CONFIG_ERROR_MALFORMED
+};
+
+struct config_item
+{
+ const char *key;
+ const char *default_value;
+ const char *description;
+};
+
+static FILE *
+get_config_file (void)
+{
+ struct str_vector paths;
+ struct str config_home, file;
+ const char *xdg_config_dirs;
+ unsigned i;
+ FILE *fp = NULL;
+
+ str_vector_init (&paths);
+
+ str_init (&config_home);
+ get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config");
+ str_vector_add (&paths, config_home.str);
+ str_free (&config_home);
+
+ if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS")))
+ split_str_ignore_empty (xdg_config_dirs, ':', &paths);
+
+ str_init (&file);
+ for (i = 0; i < paths.len; i++)
+ {
+ // As per spec, relative paths are ignored
+ if (*paths.vector[i] != '/')
+ continue;
+
+ str_reset (&file);
+ str_append (&file, paths.vector[i]);
+ str_append (&file, "/" PROGRAM_NAME "/" PROGRAM_NAME ".conf");
+
+ if ((fp = fopen (file.str, "r")))
+ break;
+ }
+
+ str_free (&file);
+ str_vector_free (&paths);
+ return fp;
+}
+
+static bool
+read_config_file (struct str_map *config, struct error **e)
+{
+ struct str line;
+ FILE *fp = get_config_file ();
+ unsigned line_no = 0;
+ bool errors = false;
+
+ if (!fp)
+ return true;
+
+ str_init (&line);
+ for (line_no = 1; read_line (fp, &line); line_no++)
+ {
+ char *start = line.str;
+ if (*start == '#')
+ continue;
+
+ while (isspace (*start))
+ start++;
+
+ char *end = strchr (start, '=');
+ if (!end)
+ {
+ if (*start)
+ {
+ error_set (e, CONFIG_ERROR, CONFIG_ERROR_MALFORMED,
+ "line %u in config: %s", line_no, "malformed input");
+ errors = true;
+ break;
+ }
+ }
+ else
+ {
+ char *value = end + 1;
+ do
+ *end = '\0';
+ while (isspace (*--end));
+
+ str_map_set (config, start, xstrdup (value));
+ }
+ }
+
+ str_free (&line);
+ fclose (fp);
+
+ return !errors;
+}
+
+// --- Configuration (application-specific) ------------------------------------
+
+static struct config_item g_config_table[] =
+{
+ { "nickname", "ZyklonB", "IRC nickname" },
+ { "username", "bot", "IRC user name" },
+ { "fullname", "ZyklonB IRC bot", "IRC full name/e-mail" },
+
+ { "irc_host", NULL, "Address of the IRC server" },
+ { "irc_port", "6667", "Port of the IRC server" },
+ { "ssl_use", "off", "Whether to use SSL" },
+ { "ssl_cert", NULL, "Client SSL certificate (PEM)" },
+ { "autojoin", NULL, "Channels to join on start" },
+ { "reconnect", "on", "Whether to reconnect on error" },
+ { "reconnect_delay", "5", "Time between reconnecting" },
+
+ { "prefix", ":", "The prefix for bot commands" },
+ { "admin", NULL, "Host mask for administrators" },
+ { "plugins", NULL, "The plugins to load on startup" },
+ { "plugin_dir", NULL, "Where to search for plugins" },
+ { "recover", "on", "Whether to re-launch on crash" },
+};
+
+static void
+load_config_defaults (struct str_map *config)
+{
+ for (size_t i = 0; i < N_ELEMENTS (g_config_table); i++)
+ {
+ const struct config_item *item = g_config_table + i;
+ if (item->default_value)
+ str_map_set (config, item->key, xstrdup (item->default_value));
+ }
+}
+
+// --- Application data --------------------------------------------------------
+
+struct plugin_data
+{
+ struct plugin_data *next; ///< The next link in a chain
+ struct plugin_data *prev; ///< The previous link in a chain
+
+ struct bot_context *ctx; ///< Parent context
+
+ pid_t pid; ///< PID of the plugin process
+ char *name; ///< Plugin identifier
+
+ bool is_zombie; ///< Whether the child is a zombie
+ bool initialized; ///< Ready to exchange IRC messages
+ struct str queued_output; ///< Output queued up until initialized
+
+ // Since we're doing non-blocking I/O, we need to queue up data so that
+ // we don't stall on plugins unnecessarily.
+
+ int read_fd; ///< The read end of the comm. pipe
+ struct str read_buffer; ///< Unprocessed input
+
+ int write_fd; ///< The write end of the comm. pipe
+ struct str write_buffer; ///< Output yet to be sent out
+};
+
+static void
+plugin_data_init (struct plugin_data *self)
+{
+ memset (self, 0, sizeof *self);
+
+ self->pid = -1;
+ str_init (&self->queued_output);
+
+ self->read_fd = -1;
+ str_init (&self->read_buffer);
+ self->write_fd = -1;
+ str_init (&self->write_buffer);
+}
+
+static void
+plugin_data_free (struct plugin_data *self)
+{
+ soft_assert (self->pid == -1);
+ free (self->name);
+
+ str_free (&self->read_buffer);
+ if (!soft_assert (self->read_fd == -1))
+ xclose (self->read_fd);
+
+ str_free (&self->write_buffer);
+ if (!soft_assert (self->write_fd == -1))
+ xclose (self->write_fd);
+
+ if (!self->initialized)
+ str_free (&self->queued_output);
+}
+
+static size_t connect_error_domain_tag;
+#define CONNECT_ERROR (error_resolve_domain (&connect_error_domain_tag))
+
+enum
+{
+ CONNECT_ERROR_INVALID_CONFIGURATION,
+ CONNECT_ERROR_FAILED
+};
+
+struct bot_context
+{
+ struct str_map config; ///< User configuration
+
+ int irc_fd; ///< Socket FD of the server
+ struct str read_buffer; ///< Input yet to be processed
+ bool irc_ready; ///< Whether we may send messages now
+
+ SSL_CTX *ssl_ctx; ///< SSL context
+ SSL *ssl; ///< SSL connection
+
+ struct plugin_data *plugins; ///< Linked list of plugins
+ struct str_map plugins_by_name; ///< Indexes @em plugins by their name
+
+ struct poller poller; ///< Manages polled descriptors
+ bool quitting; ///< User requested quitting
+ bool polling; ///< The event loop is running
+};
+
+static void
+bot_context_init (struct bot_context *ctx)
+{
+ str_map_init (&ctx->config);
+ ctx->config.free = free;
+ load_config_defaults (&ctx->config);
+
+ ctx->irc_fd = -1;
+ str_init (&ctx->read_buffer);
+ ctx->irc_ready = false;
+
+ ctx->ssl = NULL;
+ ctx->ssl_ctx = NULL;
+
+ ctx->plugins = NULL;
+ str_map_init (&ctx->plugins_by_name);
+
+ poller_init (&ctx->poller);
+ ctx->quitting = false;
+ ctx->polling = false;
+}
+
+static void
+bot_context_free (struct bot_context *ctx)
+{
+ str_map_free (&ctx->config);
+ str_free (&ctx->read_buffer);
+
+ // TODO: terminate the plugins properly before this is called
+ struct plugin_data *link, *tmp;
+ for (link = ctx->plugins; link; link = tmp)
+ {
+ tmp = link->next;
+ plugin_data_free (link);
+ free (link);
+ }
+
+ if (ctx->irc_fd != -1)
+ xclose (ctx->irc_fd);
+ if (ctx->ssl)
+ SSL_free (ctx->ssl);
+ if (ctx->ssl_ctx)
+ SSL_CTX_free (ctx->ssl_ctx);
+
+ str_map_free (&ctx->plugins_by_name);
+ poller_free (&ctx->poller);
+}
+
+static void
+irc_shutdown (struct bot_context *ctx)
+{
+ // Generally non-critical
+ if (ctx->ssl)
+ soft_assert (SSL_shutdown (ctx->ssl) != -1);
+ else
+ soft_assert (shutdown (ctx->irc_fd, SHUT_WR) == 0);
+}
+
+static void
+initiate_quit (struct bot_context *ctx)
+{
+ irc_shutdown (ctx);
+ ctx->quitting = true;
+}
+
+static void
+try_finish_quit (struct bot_context *ctx)
+{
+ if (!ctx->quitting)
+ return;
+ if (ctx->irc_fd == -1 && !ctx->plugins)
+ ctx->polling = false;
+}
+
+static bool irc_send (struct bot_context *ctx,
+ const char *format, ...) ATTRIBUTE_PRINTF (2, 3);
+
+// XXX: is it okay to just ignore the return value and wait until we receive
+// it in on_irc_readable()?
+static bool
+irc_send (struct bot_context *ctx, const char *format, ...)
+{
+ va_list ap;
+
+ if (g_debug_mode)
+ {
+ fputs ("[IRC] <== \"", stderr);
+ va_start (ap, format);
+ vfprintf (stderr, format, ap);
+ va_end (ap);
+ fputs ("\"\n", stderr);
+ }
+
+ soft_assert (ctx->irc_fd != -1);
+
+ va_start (ap, format);
+ struct str str;
+ str_init (&str);
+ str_append_vprintf (&str, format, ap);
+ str_append (&str, "\r\n");
+ va_end (ap);
+
+ bool result = true;
+ if (ctx->ssl)
+ {
+ // TODO: call SSL_get_error() to detect if a clean shutdown has occured
+ if (SSL_write (ctx->ssl, str.str, str.len) != (int) str.len)
+ {
+ print_debug ("%s: %s: %s", __func__, "SSL_write",
+ ERR_error_string (ERR_get_error (), NULL));
+ result = false;
+ }
+ }
+ else if (write (ctx->irc_fd, str.str, str.len) != (ssize_t) str.len)
+ {
+ print_debug ("%s: %s: %s", __func__, "write", strerror (errno));
+ result = false;
+ }
+
+ str_free (&str);
+ return result;
+}
+
+static bool
+irc_initialize_ssl (struct bot_context *ctx, struct error **e)
+{
+ ctx->ssl_ctx = SSL_CTX_new (SSLv23_client_method ());
+ if (!ctx->ssl_ctx)
+ goto error_ssl_1;
+ // We don't care; some encryption is always better than no encryption
+ SSL_CTX_set_verify (ctx->ssl_ctx, SSL_VERIFY_NONE, NULL);
+ // XXX: maybe we should call SSL_CTX_set_options() for some workarounds
+
+ ctx->ssl = SSL_new (ctx->ssl_ctx);
+ if (!ctx->ssl)
+ goto error_ssl_2;
+
+ const char *ssl_cert = str_map_find (&ctx->config, "ssl_cert");
+ if (ssl_cert
+ && !SSL_use_certificate_file (ctx->ssl, ssl_cert, SSL_FILETYPE_PEM))
+ {
+ // XXX: perhaps we should read the file ourselves for better messages
+ print_error ("%s: %s", "setting the SSL client certificate failed",
+ ERR_error_string (ERR_get_error (), NULL));
+ }
+
+ SSL_set_connect_state (ctx->ssl);
+ if (!SSL_set_fd (ctx->ssl, ctx->irc_fd))
+ goto error_ssl_3;
+ // Avoid SSL_write() returning SSL_ERROR_WANT_READ
+ SSL_set_mode (ctx->ssl, SSL_MODE_AUTO_RETRY);
+ if (SSL_connect (ctx->ssl) > 0)
+ return true;
+
+error_ssl_3:
+ SSL_free (ctx->ssl);
+ ctx->ssl = NULL;
+error_ssl_2:
+ SSL_CTX_free (ctx->ssl_ctx);
+ ctx->ssl_ctx = NULL;
+error_ssl_1:
+ // XXX: these error strings are really nasty; also there could be
+ // multiple errors on the OpenSSL stack.
+ error_set (e, CONNECT_ERROR, CONNECT_ERROR_FAILED,
+ "%s: %s", "could not initialize SSL",
+ ERR_error_string (ERR_get_error (), NULL));
+ return false;
+}
+
+static bool
+irc_establish_connection (struct bot_context *ctx,
+ const char *host, const char *port, bool use_ssl, struct error **e)
+{
+ struct addrinfo gai_hints, *gai_result, *gai_iter;
+ memset (&gai_hints, 0, sizeof gai_hints);
+
+ // We definitely want TCP.
+ gai_hints.ai_socktype = SOCK_STREAM;
+
+ int err = getaddrinfo (host, port, &gai_hints, &gai_result);
+ if (err)
+ {
+ error_set (e, CONNECT_ERROR, CONNECT_ERROR_FAILED, "%s: %s: %s",
+ "connection failed", "getaddrinfo", gai_strerror (err));
+ return false;
+ }
+
+ int sockfd;
+ for (gai_iter = gai_result; gai_iter; gai_iter = gai_iter->ai_next)
+ {
+ sockfd = socket (gai_iter->ai_family,
+ gai_iter->ai_socktype, gai_iter->ai_protocol);
+ if (sockfd == -1)
+ continue;
+ set_cloexec (sockfd);
+
+ int yes = 1;
+ soft_assert (setsockopt (sockfd, SOL_SOCKET, SO_KEEPALIVE,
+ &yes, sizeof yes) != -1);
+
+ const char *real_host = host;
+
+ // Let's try to resolve the address back into a real hostname;
+ // we don't really need this, so we can let it quietly fail
+ char buf[NI_MAXHOST];
+ err = getnameinfo (gai_iter->ai_addr, gai_iter->ai_addrlen,
+ buf, sizeof buf, NULL, 0, 0);
+ if (err)
+ print_debug ("%s: %s", "getnameinfo", gai_strerror (err));
+ else
+ real_host = buf;
+
+ // XXX: we shouldn't mix these statuses with `struct error'; choose 1!
+ print_status ("connecting to `%s:%s'...", real_host, port);
+ if (!connect (sockfd, gai_iter->ai_addr, gai_iter->ai_addrlen))
+ break;
+
+ xclose (sockfd);
+ }
+
+ freeaddrinfo (gai_result);
+
+ if (!gai_iter)
+ {
+ error_set (e, CONNECT_ERROR, CONNECT_ERROR_FAILED, "connection failed");
+ return false;
+ }
+
+ ctx->irc_fd = sockfd;
+ if (use_ssl && !irc_initialize_ssl (ctx, e))
+ {
+ xclose (ctx->irc_fd);
+ ctx->irc_fd = -1;
+ return false;
+ }
+
+ print_status ("connection established");
+ return true;
+}
+
+// --- Signals -----------------------------------------------------------------
+
+static int g_signal_pipe[2]; ///< A pipe used to signal... signals
+
+static struct str_vector
+ g_original_argv, ///< Original program arguments
+ g_recovery_env; ///< Environment for re-exec recovery
+
+/// Program termination has been requested by a signal
+static volatile sig_atomic_t g_termination_requested;
+
+/// Points to startup reason location within `g_recovery_environment'
+static char **g_startup_reason_location;
+/// The environment variable used to pass the startup reason when re-executing
+static const char g_startup_reason_str[] = "STARTUP_REASON";
+
+static void
+sigchld_handler (int signum)
+{
+ (void) signum;
+
+ int original_errno = errno;
+ // Just so that the read end of the pipe wakes up the poller.
+ // NOTE: Linux has signalfd() and eventfd(), and the BSD's have kqueue.
+ // All of them are better than this approach, although platform-specific.
+ if (write (g_signal_pipe[1], "c", 1) == -1)
+ soft_assert (errno == EAGAIN);
+ errno = original_errno;
+}
+
+static void
+sigterm_handler (int signum)
+{
+ (void) signum;
+
+ g_termination_requested = true;
+
+ int original_errno = errno;
+ if (write (g_signal_pipe[1], "t", 1) == -1)
+ soft_assert (errno == EAGAIN);
+ errno = original_errno;
+}
+
+static void
+setup_signal_handlers (void)
+{
+ if (pipe (g_signal_pipe) == -1)
+ {
+ print_fatal ("pipe: %s", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+
+ set_cloexec (g_signal_pipe[0]);
+ set_cloexec (g_signal_pipe[1]);
+
+ // So that the pipe cannot overflow; it would make write() block within
+ // the signal handler, which is something we really don't want to happen.
+ // The same holds true for read().
+ set_blocking (g_signal_pipe[0], false);
+ set_blocking (g_signal_pipe[1], false);
+
+ struct sigaction sa;
+ sa.sa_flags = SA_RESTART;
+ sa.sa_handler = sigchld_handler;
+ sigemptyset (&sa.sa_mask);
+
+ if (sigaction (SIGCHLD, &sa, NULL) == -1)
+ {
+ print_fatal ("sigaction: %s", strerror (errno));
+ exit (EXIT_FAILURE);
+ }
+
+ signal (SIGPIPE, SIG_IGN);
+
+ sa.sa_handler = sigterm_handler;
+ if (sigaction (SIGINT, &sa, NULL) == -1
+ || sigaction (SIGTERM, &sa, NULL) == -1)
+ print_error ("sigaction: %s", strerror (errno));
+}
+
+static void
+translate_signal_info (int no, const char **name, int code, const char **reason)
+{
+ if (code == SI_USER) *reason = "signal sent by kill()";
+ if (code == SI_QUEUE) *reason = "signal sent by sigqueue()";
+
+ switch (no)
+ {
+ case SIGILL:
+ *name = "SIGILL";
+ if (code == ILL_ILLOPC) *reason = "illegal opcode";
+ if (code == ILL_ILLOPN) *reason = "illegal operand";
+ if (code == ILL_ILLADR) *reason = "illegal addressing mode";
+ if (code == ILL_ILLTRP) *reason = "illegal trap";
+ if (code == ILL_PRVOPC) *reason = "privileged opcode";
+ if (code == ILL_PRVREG) *reason = "privileged register";
+ if (code == ILL_COPROC) *reason = "coprocessor error";
+ if (code == ILL_BADSTK) *reason = "internal stack error";
+ break;
+ case SIGFPE:
+ *name = "SIGFPE";
+ if (code == FPE_INTDIV) *reason = "integer divide by zero";
+ if (code == FPE_INTOVF) *reason = "integer overflow";
+ if (code == FPE_FLTDIV) *reason = "floating-point divide by zero";
+ if (code == FPE_FLTOVF) *reason = "floating-point overflow";
+ if (code == FPE_FLTUND) *reason = "floating-point underflow";
+ if (code == FPE_FLTRES) *reason = "floating-point inexact result";
+ if (code == FPE_FLTINV) *reason = "invalid floating-point operation";
+ if (code == FPE_FLTSUB) *reason = "subscript out of range";
+ break;
+ case SIGSEGV:
+ *name = "SIGSEGV";
+ if (code == SEGV_MAPERR)
+ *reason = "address not mapped to object";
+ if (code == SEGV_ACCERR)
+ *reason = "invalid permissions for mapped object";
+ break;
+ case SIGBUS:
+ *name = "SIGBUS";
+ if (code == BUS_ADRALN) *reason = "invalid address alignment";
+ if (code == BUS_ADRERR) *reason = "nonexistent physical address";
+ if (code == BUS_OBJERR) *reason = "object-specific hardware error";
+ break;
+ default:
+ *name = NULL;
+ }
+}
+
+static void
+recovery_handler (int signum, siginfo_t *info, void *context)
+{
+ (void) context;
+
+ // TODO: maybe try to force a core dump like this: if (fork() == 0) return;
+ // TODO: maybe we could even send "\r\nQUIT :reason\r\n" to the server. >_>
+ // As long as we're not connected via TLS, that is.
+
+ const char *signal_name = NULL, *reason = NULL;
+ translate_signal_info (signum, &signal_name, info->si_code, &reason);
+
+ char buf[128], numbuf[8];
+ if (!signal_name)
+ {
+ snprintf (numbuf, sizeof numbuf, "%d", signum);
+ signal_name = numbuf;
+ }
+
+ if (reason)
+ snprintf (buf, sizeof buf, "%s=%s: %s: %s", g_startup_reason_str,
+ "signal received", signal_name, reason);
+ else
+ snprintf (buf, sizeof buf, "%s=%s: %s", g_startup_reason_str,
+ "signal received", signal_name);
+ *g_startup_reason_location = buf;
+
+ // TODO: maybe pregenerate the path, see the following for some other ways
+ // that would be illegal to do from within a signal handler:
+ // http://stackoverflow.com/a/1024937
+ // http://stackoverflow.com/q/799679
+ // Especially if we change the current working directory in the program.
+ //
+ // Note that I can just overwrite g_orig_argv[0].
+
+ // NOTE: our children will read EOF on the read ends of their pipes as a
+ // a result of O_CLOEXEC. That should be enough to make them terminate.
+
+ char **argv = g_original_argv.vector, **argp = g_recovery_env.vector;
+ execve ("/proc/self/exe", argv, argp); // Linux
+ execve ("/proc/curproc/file", argv, argp); // BSD
+ execve ("/proc/curproc/exe", argv, argp); // BSD
+ execve ("/proc/self/path/a.out", argv, argp); // Solaris
+ execve (argv[0], argv, argp); // unreliable fallback
+
+ // Let's just crash
+ perror ("execve");
+ signal (signum, SIG_DFL);
+ raise (signum);
+}
+
+static void
+prepare_recovery_environment (void)
+{
+ str_vector_init (&g_recovery_env);
+ str_vector_add_vector (&g_recovery_env, environ);
+
+ // Prepare a location within the environment where we will put the startup
+ // (or maybe rather restart) reason in case of an irrecoverable error.
+ char **iter;
+ for (iter = g_recovery_env.vector; *iter; iter++)
+ {
+ const size_t len = sizeof g_startup_reason_str - 1;
+ if (!strncmp (*iter, g_startup_reason_str, len) && (*iter)[len] == '=')
+ break;
+ }
+
+ if (iter)
+ g_startup_reason_location = iter;
+ else
+ {
+ str_vector_add (&g_recovery_env, "");
+ g_startup_reason_location =
+ g_recovery_env.vector + g_recovery_env.len - 1;
+ }
+}
+
+static void
+setup_recovery_handler (struct bot_context *ctx)
+{
+ const char *recover_str = str_map_find (&ctx->config, "recover");
+ hard_assert (recover_str != NULL); // We have a default value for this
+
+ bool recover;
+ if (!set_boolean_if_valid (&recover, recover_str))
+ {
+ print_fatal ("invalid configuration value for `%s'", "recover");
+ exit (EXIT_FAILURE);
+ }
+ if (!recover)
+ return;
+
+ // Make sure these signals aren't blocked, otherwise we would be unable
+ // to handle them, making the critical conditions fatal.
+ sigset_t mask;
+ sigemptyset (&mask);
+ sigaddset (&mask, SIGSEGV);
+ sigaddset (&mask, SIGBUS);
+ sigaddset (&mask, SIGFPE);
+ sigaddset (&mask, SIGILL);
+ sigprocmask (SIG_UNBLOCK, &mask, NULL);
+
+ struct sigaction sa;
+ sa.sa_flags = SA_SIGINFO;
+ sa.sa_sigaction = recovery_handler;
+ sigemptyset (&sa.sa_mask);
+
+ prepare_recovery_environment ();
+
+ // TODO: also handle SIGABRT... or avoid doing abort() in the first place?
+ if (sigaction (SIGSEGV, &sa, NULL) == -1
+ || sigaction (SIGBUS, &sa, NULL) == -1
+ || sigaction (SIGFPE, &sa, NULL) == -1
+ || sigaction (SIGILL, &sa, NULL) == -1)
+ print_error ("sigaction: %s", strerror (errno));
+}
+
+// --- Plugins -----------------------------------------------------------------
+
+/// The name of the special IRC command for interprocess communication
+static const char *plugin_ipc_command = "ZYKLONB";
+
+static size_t plugin_error_domain_tag;
+#define PLUGIN_ERROR (error_resolve_domain (&plugin_error_domain_tag))
+
+enum
+{
+ PLUGIN_ERROR_ALREADY_LOADED,
+ PLUGIN_ERROR_NOT_LOADED,
+ PLUGIN_ERROR_LOADING_FAILED
+};
+
+static struct plugin_data *
+plugin_find_by_pid (struct bot_context *ctx, pid_t pid)
+{
+ struct plugin_data *iter;
+ for (iter = ctx->plugins; iter; iter = iter->next)
+ if (iter->pid == pid)
+ return iter;
+ return NULL;
+}
+
+static bool
+plugin_zombify (struct plugin_data *plugin)
+{
+ if (plugin->is_zombie)
+ return false;
+
+ // FIXME: make sure that we don't remove entries from the poller while we
+ // still may have stuff to read; maybe just check that the read pipe is
+ // empty before closing it... and then on EOF check if `pid == -1' and
+ // only then dispose of it (it'd be best to simulate that both of these
+ // cases may happen).
+ ssize_t poller_idx =
+ poller_find_by_fd (&plugin->ctx->poller, plugin->write_fd);
+ if (poller_idx != -1)
+ poller_remove_at_index (&plugin->ctx->poller, poller_idx);
+
+ // TODO: try to flush the write buffer (non-blocking)?
+
+ // The plugin should terminate itself after it receives EOF.
+ xclose (plugin->write_fd);
+ plugin->write_fd = -1;
+
+ // Make it a pseudo-anonymous zombie. In this state we process any
+ // remaining commands it attempts to send to us before it finally dies.
+ str_map_set (&plugin->ctx->plugins_by_name, plugin->name, NULL);
+ plugin->is_zombie = true;
+ return true;
+}
+
+static void
+on_plugin_writable (const struct pollfd *fd, struct plugin_data *plugin)
+{
+ struct bot_context *ctx = plugin->ctx;
+ struct str *buf = &plugin->write_buffer;
+ size_t written_total = 0;
+
+ // TODO: see "Advanced Programming in the UNIX Environment" Figure C.19;
+ // check for any unexpected behaviour that might occur
+ if (fd->revents != POLLOUT)
+ print_debug ("poller fd %d: revents: %d", fd->fd, fd->revents);
+
+ while (written_total != buf->len)
+ {
+ ssize_t n_written = write (fd->fd, buf->str + written_total,
+ buf->len - written_total);
+
+ if (n_written < 0)
+ {
+ if (errno == EAGAIN)
+ break;
+
+ if (!soft_assert (errno == EINTR) && !plugin->is_zombie)
+ {
+ print_debug ("%s: %s", "recv", strerror (errno));
+ print_error ("failure on writing to plugin `%s',"
+ " therefore I'm unloading it", plugin->name);
+ plugin_zombify (plugin);
+ break;
+ }
+ }
+
+ // This may be equivalent to EAGAIN on some implementations
+ if (n_written == 0)
+ break;
+
+ written_total += n_written;
+ }
+
+ if (written_total != 0)
+ str_remove_slice (buf, 0, written_total);
+
+ if (buf->len == 0)
+ {
+ // Everything has been written, there's no need to end up in here again
+ ssize_t index = poller_find_by_fd (&ctx->poller, fd->fd);
+ if (index != -1)
+ poller_remove_at_index (&ctx->poller, index);
+ }
+}
+
+static void
+plugin_queue_write (struct plugin_data *plugin)
+{
+ if (plugin->is_zombie)
+ return;
+
+ // Don't let the write buffer grow infinitely. If there's a ton of data
+ // waiting to be processed by the plugin, it usually means there's something
+ // wrong with it (such as someone stopping the process).
+ if (plugin->write_buffer.len >= (1 << 20))
+ {
+ print_warning ("plugin `%s' does not seem to process messages fast"
+ " enough, I'm unloading it", plugin->name);
+ plugin_zombify (plugin);
+ return;
+ }
+
+ poller_set (&plugin->ctx->poller, plugin->write_fd, POLLOUT,
+ (poller_dispatcher_func) on_plugin_writable, plugin);
+}
+
+static void
+plugin_send (struct plugin_data *plugin, const char *format, ...)
+ ATTRIBUTE_PRINTF (2, 3);
+
+static void
+plugin_send (struct plugin_data *plugin, const char *format, ...)
+{
+ va_list ap;
+
+ if (g_debug_mode)
+ {
+ fprintf (stderr, "[%s] <-- \"", plugin->name);
+ va_start (ap, format);
+ vfprintf (stderr, format, ap);
+ va_end (ap);
+ fputs ("\"\n", stderr);
+ }
+
+ va_start (ap, format);
+ str_append_vprintf (&plugin->write_buffer, format, ap);
+ va_end (ap);
+ str_append (&plugin->write_buffer, "\r\n");
+
+ plugin_queue_write (plugin);
+}
+
+static void
+plugin_process_message (const struct irc_message *msg,
+ const char *raw, void *user_data)
+{
+ struct plugin_data *plugin = user_data;
+ struct bot_context *ctx = plugin->ctx;
+
+ if (g_debug_mode)
+ fprintf (stderr, "[%s] --> \"%s\"\n", plugin->name, raw);
+
+ if (!strcasecmp (msg->command, plugin_ipc_command))
+ {
+ // Replies are sent in the order in which they came in, so there's
+ // no need to attach a special identifier to them. It might be
+ // desirable in some cases, though.
+
+ if (msg->params.len < 1)
+ return;
+
+ const char *command = msg->params.vector[0];
+ if (!strcasecmp (command, "register"))
+ {
+ // Register for relaying of IRC traffic
+ plugin->initialized = true;
+
+ // Flush any queued up traffic here. The point of queuing it in
+ // the first place is so that we don't have to wait for plugin
+ // initialization during startup.
+ //
+ // Note that if we start filtering data coming to the plugins e.g.
+ // based on what it tells us upon registration, we might need to
+ // filter `queued_output' as well.
+ str_append_str (&plugin->write_buffer, &plugin->queued_output);
+ str_free (&plugin->queued_output);
+
+ // NOTE: this may trigger the buffer length check
+ plugin_queue_write (plugin);
+ }
+ else if (!strcasecmp (command, "get_config"))
+ {
+ if (msg->params.len < 2)
+ return;
+
+ const char *value =
+ str_map_find (&ctx->config, msg->params.vector[1]);
+ // TODO: escape the value (although there's no need to ATM)
+ plugin_send (plugin, "%s :%s",
+ plugin_ipc_command, value ? value : "");
+ }
+ else if (!strcasecmp (command, "print"))
+ {
+ if (msg->params.len < 2)
+ return;
+
+ printf ("%s", msg->params.vector[1]);
+ }
+ }
+ else if (plugin->initialized)
+ {
+ // Pass everything else through to the IRC server
+ irc_send (ctx, "%s", raw);
+ }
+}
+
+static void
+on_plugin_readable (const struct pollfd *fd, struct plugin_data *plugin)
+{
+ // TODO: see "Advanced Programming in the UNIX Environment" Figure C.19;
+ // check for any unexpected behaviour that might occur
+ if (fd->revents != POLLIN)
+ print_debug ("poller fd %d: revents: %d", fd->fd, fd->revents);
+
+ // TODO: see if I can reuse irc_fill_read_buffer()
+ struct str *buf = &plugin->read_buffer;
+ while (true)
+ {
+ str_ensure_space (buf, 512 + 1);
+ ssize_t n_read = read (fd->fd, buf->str + buf->len,
+ buf->alloc - buf->len - 1);
+
+ if (n_read < 0)
+ {
+ if (errno == EAGAIN)
+ break;
+ if (soft_assert (errno == EINTR))
+ continue;
+
+ if (!plugin->is_zombie)
+ {
+ print_error ("failure on reading from plugin `%s',"
+ " therefore I'm unloading it", plugin->name);
+ plugin_zombify (plugin);
+ }
+ return;
+ }
+
+ // EOF; hopefully it will die soon (maybe it already has)
+ if (n_read == 0)
+ break;
+
+ buf->str[buf->len += n_read] = '\0';
+ if (buf->len >= (1 << 20))
+ {
+ // XXX: this isn't really the best flood prevention mechanism,
+ // but it wasn't even supposed to be one.
+ if (plugin->is_zombie)
+ {
+ print_error ("a zombie of plugin `%s' is trying to flood us,"
+ " therefore I'm killing it", plugin->name);
+ kill (plugin->pid, SIGKILL);
+ }
+ else
+ {
+ print_error ("plugin `%s' seems to spew out data frantically,"
+ " therefore I'm unloading it", plugin->name);
+ plugin_zombify (plugin);
+ }
+ return;
+ }
+ }
+
+ // Hold it in the buffer while we're disconnected
+ struct bot_context *ctx = plugin->ctx;
+ if (ctx->irc_fd != -1 && ctx->irc_ready)
+ irc_process_buffer (buf, plugin_process_message, plugin);
+}
+
+static bool
+is_valid_plugin_name (const char *name)
+{
+ if (!*name)
+ return false;
+ for (const char *p = name; *p; p++)
+ if (!isgraph (*p) || *p == '/')
+ return false;
+ return true;
+}
+
+static bool
+plugin_load (struct bot_context *ctx, const char *name, struct error **e)
+{
+ const char *plugin_dir = str_map_find (&ctx->config, "plugin_dir");
+ if (!plugin_dir)
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_LOADING_FAILED,
+ "plugin directory not set");
+ return false;
+ }
+
+ if (!is_valid_plugin_name (name))
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_LOADING_FAILED,
+ "invalid plugin name");
+ return false;
+ }
+
+ if (str_map_find (&ctx->plugins_by_name, name))
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_ALREADY_LOADED,
+ "the plugin has already been loaded");
+ return false;
+ }
+
+ int stdin_pipe[2];
+ if (pipe (stdin_pipe) == -1)
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_LOADING_FAILED, "%s: %s: %s",
+ "failed to load the plugin", "pipe", strerror (errno));
+ goto fail_1;
+ }
+
+ int stdout_pipe[2];
+ if (pipe (stdout_pipe) == -1)
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_LOADING_FAILED, "%s: %s: %s",
+ "failed to load the plugin", "pipe", strerror (errno));
+ goto fail_2;
+ }
+
+ set_cloexec (stdin_pipe[1]);
+ set_cloexec (stdout_pipe[0]);
+
+ pid_t pid = fork ();
+ if (pid == -1)
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_LOADING_FAILED, "%s: %s: %s",
+ "failed to load the plugin", "fork", strerror (errno));
+ goto fail_3;
+ }
+
+ if (pid == 0)
+ {
+ // Redirect the child's stdin and stdout to the pipes
+ hard_assert (dup2 (stdin_pipe[0], STDIN_FILENO) != -1);
+ hard_assert (dup2 (stdout_pipe[1], STDOUT_FILENO) != -1);
+
+ xclose (stdin_pipe[0]);
+ xclose (stdout_pipe[1]);
+
+ struct str pathname;
+ str_init (&pathname);
+ str_append (&pathname, plugin_dir);
+ str_append_c (&pathname, '/');
+ str_append (&pathname, name);
+
+ // Restore some of the signal handling
+ signal (SIGPIPE, SIG_DFL);
+
+ char *const argv[] = { pathname.str, NULL };
+ execve (argv[0], argv, environ);
+
+ // We will collect the failure later via SIGCHLD
+ print_fatal ("%s: %s: %s",
+ "failed to load the plugin", "exec", strerror (errno));
+ _exit (EXIT_FAILURE);
+ }
+
+ xclose (stdin_pipe[0]);
+ xclose (stdout_pipe[1]);
+
+ set_blocking (stdout_pipe[0], false);
+ set_blocking (stdin_pipe[1], false);
+
+ struct plugin_data *plugin = xmalloc (sizeof *plugin);
+ plugin_data_init (plugin);
+ plugin->ctx = ctx;
+ plugin->pid = pid;
+ plugin->name = xstrdup (name);
+ plugin->read_fd = stdout_pipe[0];
+ plugin->write_fd = stdin_pipe[1];
+
+ LIST_PREPEND (ctx->plugins, plugin);
+ str_map_set (&ctx->plugins_by_name, name, plugin);
+
+ poller_set (&ctx->poller, stdout_pipe[0], POLLIN,
+ (poller_dispatcher_func) on_plugin_readable, plugin);
+ return true;
+
+fail_3:
+ xclose (stdout_pipe[0]);
+ xclose (stdout_pipe[1]);
+fail_2:
+ xclose (stdin_pipe[0]);
+ xclose (stdin_pipe[1]);
+fail_1:
+ return false;
+}
+
+static bool
+plugin_unload (struct bot_context *ctx, const char *name, struct error **e)
+{
+ struct plugin_data *plugin = str_map_find (&ctx->plugins_by_name, name);
+
+ if (!plugin)
+ {
+ error_set (e, PLUGIN_ERROR, PLUGIN_ERROR_NOT_LOADED,
+ "no such plugin is loaded");
+ return false;
+ }
+
+ plugin_zombify (plugin);
+
+ // TODO: add a `kill zombies' command to forcefully get rid of processes
+ // that do not understand the request.
+ // TODO: set a timeout before we go for a kill automatically (and if this
+ // was a reload request, try to bring the plugin back up)
+ return true;
+}
+
+static void
+plugin_load_all_from_config (struct bot_context *ctx)
+{
+ const char *plugin_list = str_map_find (&ctx->config, "plugins");
+ if (!plugin_list)
+ return;
+
+ struct str_vector plugins;
+ str_vector_init (&plugins);
+
+ split_str_ignore_empty (plugin_list, ',', &plugins);
+ for (size_t i = 0; i < plugins.len; i++)
+ {
+ char *name = strip_str_in_place (plugins.vector[i], " ");
+
+ struct error *e = NULL;
+ if (!plugin_load (ctx, name, &e))
+ {
+ print_error ("plugin `%s' failed to load: %s", name, e->message);
+ error_free (e);
+ }
+ }
+
+ str_vector_free (&plugins);
+}
+
+// --- Main program ------------------------------------------------------------
+
+static bool
+parse_bot_command (const char *s, const char *command, const char **following)
+{
+ size_t command_len = strlen (command);
+ if (strncasecmp (s, command, command_len))
+ return false;
+ s += command_len;
+
+ // Expect a word boundary, so that we don't respond to invalid things
+ if (isalnum (*s))
+ return false;
+
+ // Ignore any initial spaces; the rest is the command's argument
+ while (isblank (*s))
+ s++;
+ *following = s;
+ return true;
+}
+
+static void
+split_bot_command_argument_list (const char *arguments, struct str_vector *out)
+{
+ split_str_ignore_empty (arguments, ',', out);
+ for (size_t i = 0; i < out->len; )
+ {
+ if (!*strip_str_in_place (out->vector[i], " \t"))
+ str_vector_remove (out, i);
+ else
+ i++;
+ }
+}
+
+static bool
+is_private_message (const struct irc_message *msg)
+{
+ hard_assert (msg->params.len);
+ return !strchr ("#&+!", *msg->params.vector[0]);
+}
+
+static bool
+is_sent_by_admin (struct bot_context *ctx, const struct irc_message *msg)
+{
+ const char *admin = str_map_find (&ctx->config, "admin");
+
+ // No administrator set -> everyone is an administrator
+ if (!admin)
+ return true;
+
+ // TODO: precompile the regex
+ struct error *e = NULL;
+ if (regex_match (admin, msg->prefix, NULL))
+ return true;
+
+ if (e)
+ {
+ print_error ("%s: %s", "invalid admin mask", e->message);
+ error_free (e);
+ return true;
+ }
+
+ return false;
+}
+
+static void respond_to_user (struct bot_context *ctx, const struct
+ irc_message *msg, const char *format, ...) ATTRIBUTE_PRINTF (3, 4);
+
+static void
+respond_to_user (struct bot_context *ctx, const struct irc_message *msg,
+ const char *format, ...)
+{
+ if (!soft_assert (msg->prefix && msg->params.len))
+ return;
+
+ char nick[strcspn (msg->prefix, "!") + 1];
+ strncpy (nick, msg->prefix, sizeof nick - 1);
+ nick[sizeof nick - 1] = '\0';
+
+ struct str text;
+ va_list ap;
+
+ str_init (&text);
+ va_start (ap, format);
+ str_append_vprintf (&text, format, ap);
+ va_end (ap);
+
+ if (is_private_message (msg))
+ irc_send (ctx, "PRIVMSG %s :%s", nick, text.str);
+ else
+ irc_send (ctx, "PRIVMSG %s :%s: %s",
+ msg->params.vector[0], nick, text.str);
+
+ str_free (&text);
+}
+
+static void
+process_plugin_load (struct bot_context *ctx,
+ const struct irc_message *msg, const char *name)
+{
+ struct error *e = NULL;
+ if (plugin_load (ctx, name, &e))
+ respond_to_user (ctx, msg, "plugin `%s' queued for loading", name);
+ else
+ {
+ respond_to_user (ctx, msg, "plugin `%s' could not be loaded: %s",
+ name, e->message);
+ error_free (e);
+ }
+}
+
+static void
+process_plugin_unload (struct bot_context *ctx,
+ const struct irc_message *msg, const char *name)
+{
+ struct error *e = NULL;
+ if (plugin_unload (ctx, name, &e))
+ respond_to_user (ctx, msg, "plugin `%s' unloaded", name);
+ else
+ {
+ respond_to_user (ctx, msg, "plugin `%s' could not be unloaded: %s",
+ name, e->message);
+ error_free (e);
+ }
+}
+
+static void
+process_plugin_reload (struct bot_context *ctx,
+ const struct irc_message *msg, const char *name)
+{
+ // So far the only error that can occur is that the plugin hasn't been
+ // loaded, which in this case doesn't really matter.
+ plugin_unload (ctx, name, NULL);
+
+ process_plugin_load (ctx, msg, name);
+}
+
+static void
+process_privmsg (struct bot_context *ctx, const struct irc_message *msg)
+{
+ if (!is_sent_by_admin (ctx, msg))
+ return;
+ if (msg->params.len < 2)
+ return;
+
+ const char *prefix = str_map_find (&ctx->config, "prefix");
+ hard_assert (prefix != NULL); // We have a default value for this
+
+ // For us to recognize the command, it has to start with the prefix,
+ // with the exception of PM's sent directly to us.
+ const char *text = msg->params.vector[1];
+ if (!strncmp (text, prefix, strlen (prefix)))
+ text += strlen (prefix);
+ else if (!is_private_message (msg))
+ return;
+
+ const char *following;
+ struct str_vector list;
+ str_vector_init (&list);
+
+ if (parse_bot_command (text, "quote", &following))
+ // This seems to replace tons of random stupid commands
+ irc_send (ctx, "%s", following);
+ else if (parse_bot_command (text, "quit", &following))
+ {
+ // We actually need this command (instead of just `quote') because we
+ // could try to reconnect to the server automatically otherwise.
+ if (*following)
+ irc_send (ctx, "QUIT :%s", following);
+ else
+ irc_send (ctx, "QUIT");
+ initiate_quit (ctx);
+ }
+ else if (parse_bot_command (text, "status", &following))
+ {
+ struct str report;
+ str_init (&report);
+
+ const char *reason = getenv (g_startup_reason_str);
+ if (!reason)
+ reason = "launched normally";
+ str_append_printf (&report, "\x02startup reason:\x0f %s, ", reason);
+
+ str_append (&report, "\x02plugins:\x0f ");
+ size_t zombies = 0;
+ for (struct plugin_data *plugin = ctx->plugins;
+ plugin; plugin = plugin->next)
+ {
+ if (plugin->is_zombie)
+ zombies++;
+ else
+ str_append_printf (&report, "%s, ", plugin->name);
+ }
+ if (!ctx->plugins)
+ str_append (&report, "\x02none\x0f, ");
+ str_append_printf (&report, "\x02zombies:\x0f %zu", zombies);
+
+ respond_to_user (ctx, msg, "%s", report.str);
+ str_free (&report);
+ }
+ else if (parse_bot_command (text, "load", &following))
+ {
+ split_bot_command_argument_list (following, &list);
+ for (size_t i = 0; i < list.len; i++)
+ process_plugin_load (ctx, msg, list.vector[i]);
+ }
+ else if (parse_bot_command (text, "reload", &following))
+ {
+ split_bot_command_argument_list (following, &list);
+ for (size_t i = 0; i < list.len; i++)
+ process_plugin_reload (ctx, msg, list.vector[i]);
+ }
+ else if (parse_bot_command (text, "unload", &following))
+ {
+ split_bot_command_argument_list (following, &list);
+ for (size_t i = 0; i < list.len; i++)
+ process_plugin_unload (ctx, msg, list.vector[i]);
+ }
+
+ str_vector_free (&list);
+}
+
+static void
+irc_process_message (const struct irc_message *msg,
+ const char *raw, void *user_data)
+{
+ struct bot_context *ctx = user_data;
+ if (g_debug_mode)
+ fprintf (stderr, "[%s] ==> \"%s\"\n", "IRC", raw);
+
+ // This should be as minimal as possible, I don't want to have the whole bot
+ // written in C, especially when I have this overengineered plugin system.
+ // Therefore the very basic functionality only.
+ //
+ // I should probably even rip out the autojoin...
+
+ // First forward the message to all the plugins
+ for (struct plugin_data *plugin = ctx->plugins;
+ plugin; plugin = plugin->next)
+ {
+ if (plugin->is_zombie)
+ continue;
+
+ if (plugin->initialized)
+ plugin_send (plugin, "%s", raw);
+ else
+ // TODO: make sure that this buffer doesn't get too large either
+ str_append_printf (&plugin->queued_output, "%s\r\n", raw);
+ }
+
+ if (!strcasecmp (msg->command, "PING"))
+ {
+ if (msg->params.len)
+ irc_send (ctx, "PONG :%s", msg->params.vector[0]);
+ else
+ irc_send (ctx, "PONG");
+ }
+ else if (!ctx->irc_ready && (!strcasecmp (msg->command, "MODE")
+ || !strcasecmp (msg->command, "376") // RPL_ENDOFMOTD
+ || !strcasecmp (msg->command, "422"))) // ERR_NOMOTD
+ {
+ print_status ("successfully connected");
+ ctx->irc_ready = true;
+
+ const char *autojoin = str_map_find (&ctx->config, "autojoin");
+ if (autojoin)
+ irc_send (ctx, "JOIN :%s", autojoin);
+ }
+ else if (!strcasecmp (msg->command, "PRIVMSG"))
+ process_privmsg (ctx, msg);
+}
+
+enum irc_read_result
+{
+ IRC_READ_OK, ///< Some data were read successfully
+ IRC_READ_EOF, ///< The server has closed connection
+ IRC_READ_AGAIN, ///< No more data at the moment
+ IRC_READ_ERROR ///< General connection failure
+};
+
+static enum irc_read_result
+irc_fill_read_buffer_ssl (struct bot_context *ctx, struct str *buf)
+{
+ int n_read;
+start:
+ n_read = SSL_read (ctx->ssl, buf->str + buf->len,
+ buf->alloc - buf->len - 1 /* null byte */);
+
+ const char *error_info = NULL;
+ switch (SSL_get_error (ctx->ssl, n_read))
+ {
+ case SSL_ERROR_NONE:
+ buf->str[buf->len += n_read] = '\0';
+ return IRC_READ_AGAIN;
+ case SSL_ERROR_ZERO_RETURN:
+ return IRC_READ_EOF;
+ case SSL_ERROR_WANT_READ:
+ return IRC_READ_AGAIN;
+ case SSL_ERROR_WANT_WRITE:
+ {
+ // Let it finish the handshake as we don't poll for writability;
+ // any errors are to be collected by SSL_read() in the next iteration
+ struct pollfd pfd = { .fd = ctx->irc_fd, .events = POLLOUT };
+ soft_assert (poll (&pfd, 1, 0) > 0);
+ goto start;
+ }
+ case SSL_ERROR_SYSCALL:
+ {
+ int err;
+ if ((err = ERR_get_error ()))
+ error_info = ERR_error_string (err, NULL);
+ else if (n_read == 0)
+ return IRC_READ_EOF;
+ else
+ {
+ if (errno == EINTR)
+ goto start;
+ error_info = strerror (errno);
+ }
+ break;
+ }
+ case SSL_ERROR_SSL:
+ default:
+ error_info = ERR_error_string (ERR_get_error (), NULL);
+ }
+
+ print_debug ("%s: %s: %s", __func__, "SSL_read", error_info);
+ return IRC_READ_ERROR;
+}
+
+static enum irc_read_result
+irc_fill_read_buffer (struct bot_context *ctx, struct str *buf)
+{
+ ssize_t n_read;
+start:
+ n_read = recv (ctx->irc_fd, buf->str + buf->len,
+ buf->alloc - buf->len - 1 /* null byte */, 0);
+
+ if (n_read > 0)
+ {
+ buf->str[buf->len += n_read] = '\0';
+ return IRC_READ_OK;
+ }
+ if (n_read == 0)
+ return IRC_READ_EOF;
+
+ if (errno == EAGAIN)
+ return IRC_READ_AGAIN;
+ if (errno == EINTR)
+ goto start;
+
+ print_debug ("%s: %s: %s", __func__, "recv", strerror (errno));
+ return IRC_READ_ERROR;
+}
+
+static bool irc_connect (struct bot_context *ctx, struct error **e);
+
+static void
+irc_try_reconnect (struct bot_context *ctx)
+{
+ if (!soft_assert (ctx->irc_fd == -1))
+ return;
+
+ const char *reconnect_str = str_map_find (&ctx->config, "reconnect");
+ hard_assert (reconnect_str != NULL); // We have a default value for this
+
+ bool reconnect;
+ if (!set_boolean_if_valid (&reconnect, reconnect_str))
+ {
+ print_fatal ("invalid configuration value for `%s'", "recover");
+ try_finish_quit (ctx);
+ return;
+ }
+ if (!reconnect)
+ return;
+
+ const char *delay_str = str_map_find (&ctx->config, "reconnect_delay");
+ hard_assert (delay_str != NULL); // We have a default value for this
+
+ char *end_ptr;
+ errno = 0;
+ long delay = strtol (delay_str, &end_ptr, 10);
+ if (errno != 0 || end_ptr == delay_str || *end_ptr)
+ {
+ print_error ("invalid configuration value for `%s'",
+ "reconnect_delay");
+ delay = 0;
+ }
+
+ while (true)
+ {
+ // TODO: this would be better suited by a timeout event;
+ // remember to update try_finish_quit() etc. to reflect this
+ print_status ("trying to reconnect in %ld seconds...", delay);
+ sleep (delay);
+
+ struct error *e = NULL;
+ if (irc_connect (ctx, &e))
+ break;
+
+ print_error ("%s", e->message);
+ error_free (e);
+ }
+
+ // TODO: inform plugins about the new connection
+}
+
+static void
+on_irc_disconnected (struct bot_context *ctx)
+{
+ // Get rid of the dead socket etc.
+ if (ctx->ssl)
+ {
+ SSL_free (ctx->ssl);
+ ctx->ssl = NULL;
+ SSL_CTX_free (ctx->ssl_ctx);
+ ctx->ssl_ctx = NULL;
+ }
+
+ ssize_t i = poller_find_by_fd (&ctx->poller, ctx->irc_fd);
+ if (i != -1)
+ poller_remove_at_index (&ctx->poller, i);
+
+ xclose (ctx->irc_fd);
+ ctx->irc_fd = -1;
+
+ // TODO: inform plugins about the disconnect event
+
+ if (ctx->quitting)
+ {
+ // Unload all plugins
+ // TODO: wait for a few seconds and then send SIGKILL to all plugins
+ for (struct plugin_data *plugin = ctx->plugins;
+ plugin; plugin = plugin->next)
+ plugin_zombify (plugin);
+
+ try_finish_quit (ctx);
+ return;
+ }
+
+ irc_try_reconnect (ctx);
+}
+
+static void
+on_irc_readable (const struct pollfd *fd, struct bot_context *ctx)
+{
+ if (fd->revents != POLLIN)
+ print_debug ("poller fd %d: revents: %d", fd->fd, fd->revents);
+
+ (void) set_blocking (ctx->irc_fd, false);
+
+ struct str *buf = &ctx->read_buffer;
+ enum irc_read_result (*fill_buffer)(struct bot_context *, struct str *)
+ = ctx->ssl
+ ? irc_fill_read_buffer_ssl
+ : irc_fill_read_buffer;
+ bool disconnected = false;
+ while (true)
+ {
+ str_ensure_space (buf, 512);
+ switch (fill_buffer (ctx, buf))
+ {
+ case IRC_READ_AGAIN:
+ goto end;
+ case IRC_READ_ERROR:
+ print_error ("reading from the IRC server failed");
+ disconnected = true;
+ goto end;
+ case IRC_READ_EOF:
+ print_status ("the IRC server closed the connection");
+ disconnected = true;
+ goto end;
+ case IRC_READ_OK:
+ break;
+ }
+
+ if (buf->len >= (1 << 20))
+ {
+ print_fatal ("the IRC server seems to spew out data frantically");
+ irc_shutdown (ctx);
+ goto end;
+ }
+ }
+end:
+ (void) set_blocking (ctx->irc_fd, true);
+ irc_process_buffer (buf, irc_process_message, ctx);
+
+ if (disconnected)
+ on_irc_disconnected (ctx);
+}
+
+static bool
+irc_connect (struct bot_context *ctx, struct error **e)
+{
+ const char *irc_host = str_map_find (&ctx->config, "irc_host");
+ const char *irc_port = str_map_find (&ctx->config, "irc_port");
+ const char *ssl_use_str = str_map_find (&ctx->config, "ssl_use");
+
+ const char *nickname = str_map_find (&ctx->config, "nickname");
+ const char *username = str_map_find (&ctx->config, "username");
+ const char *fullname = str_map_find (&ctx->config, "fullname");
+
+ // We have a default value for these
+ hard_assert (irc_port && ssl_use_str);
+ hard_assert (nickname && username && fullname);
+
+ // TODO: again, get rid of `struct error' in here. The question is: how
+ // do we tell our caller that he should not try to reconnect?
+ if (!irc_host)
+ {
+ error_set (e, CONNECT_ERROR, CONNECT_ERROR_INVALID_CONFIGURATION,
+ "no hostname specified in configuration");
+ return false;
+ }
+
+ bool use_ssl;
+ if (!set_boolean_if_valid (&use_ssl, ssl_use_str))
+ {
+ error_set (e, CONNECT_ERROR, CONNECT_ERROR_INVALID_CONFIGURATION,
+ "invalid configuration value for `%s'", "use_ssl");
+ return false;
+ }
+
+ if (!irc_establish_connection (ctx, irc_host, irc_port, use_ssl, e))
+ return false;
+
+ // TODO: set a timeout on the socket, something like 30 minutes, then we
+ // should ideally send a PING... or just forcefully reconnect.
+ //
+ // TODO: in exec try: 1/ set blocking, 2/ setsockopt() SO_LINGER,
+ // (struct linger) { .l_onoff = true; .l_linger = 1 /* 1s should do */; }
+ // 3/ /* O_CLOEXEC */ But only if the QUIT message proves unreliable.
+ poller_set (&ctx->poller, ctx->irc_fd, POLLIN,
+ (poller_dispatcher_func) on_irc_readable, ctx);
+
+ // TODO: probably check for errors from these calls as well
+ irc_send (ctx, "NICK %s", nickname);
+ irc_send (ctx, "USER %s 8 * :%s", username, fullname);
+ return true;
+}
+
+static void
+on_signal_pipe_readable (const struct pollfd *fd, struct bot_context *ctx)
+{
+ char *dummy;
+ (void) read (fd->fd, &dummy, 1);
+
+ // XXX: do we need to check if we have a connection?
+ if (g_termination_requested && !ctx->quitting)
+ {
+ irc_send (ctx, "QUIT :Terminated by signal");
+ initiate_quit (ctx);
+ }
+
+ // Reap all dead children (since the pipe may overflow, we ask waitpid()
+ // to return all the zombies it knows about).
+ while (true)
+ {
+ int status;
+ pid_t zombie = waitpid (-1, &status, WNOHANG);
+
+ if (zombie == -1)
+ {
+ // No children to wait on
+ if (errno == ECHILD)
+ break;
+
+ hard_assert (errno == EINTR);
+ continue;
+ }
+
+ if (zombie == 0)
+ break;
+
+ struct plugin_data *plugin = plugin_find_by_pid (ctx, zombie);
+ // Something has died but we don't recognize it (re-exec?)
+ if (!soft_assert (plugin != NULL))
+ continue;
+
+ // TODO: callbacks on children death, so that we may tell the user
+ // "plugin `name' died like a dirty jewish pig"; use `status'
+ if (!plugin->is_zombie && WIFSIGNALED (status))
+ {
+ char *notes = "";
+#ifdef WCOREDUMP
+ if (WCOREDUMP (status))
+ notes = " (core dumped)";
+#endif
+ print_warning ("Plugin `%s' died from signal %d%s",
+ plugin->name, WTERMSIG (status), notes);
+ }
+
+ // Let's go through the zombie state to simplify things a bit
+ // TODO: might not be a completely bad idea to restart the plugin
+ plugin_zombify (plugin);
+
+ plugin->pid = -1;
+
+ ssize_t poller_idx = poller_find_by_fd (&ctx->poller, plugin->read_fd);
+ if (poller_idx != -1)
+ poller_remove_at_index (&ctx->poller, poller_idx);
+
+ xclose (plugin->read_fd);
+ plugin->read_fd = -1;
+
+ LIST_UNLINK (ctx->plugins, plugin);
+ plugin_data_free (plugin);
+ free (plugin);
+
+ // Living child processes block us from quitting
+ try_finish_quit (ctx);
+ }
+}
+
+static void
+write_default_configuration (const char *filename)
+{
+ struct str path, base;
+ int status = EXIT_SUCCESS;
+
+ str_init (&path);
+ str_init (&base);
+
+ if (filename)
+ {
+ char *tmp = xstrdup (filename);
+ str_append (&path, dirname (tmp));
+ strcpy (tmp, filename);
+ str_append (&base, basename (tmp));
+ free (tmp);
+ }
+ else
+ {
+ get_xdg_home_dir (&path, "XDG_CONFIG_HOME", ".config");
+ str_append (&path, "/" PROGRAM_NAME);
+ str_append (&base, PROGRAM_NAME ".conf");
+ }
+
+ struct error *e = NULL;
+ if (!mkdir_with_parents (path.str, &e))
+ {
+ print_fatal ("%s", e->message);
+ status = EXIT_FAILURE;
+ goto out;
+ }
+
+ str_append_c (&path, '/');
+ str_append_str (&path, &base);
+
+ FILE *fp = fopen (path.str, "w");
+ if (!fp)
+ {
+ print_fatal ("could not open `%s' for writing: %s",
+ path.str, strerror (errno));
+ status = EXIT_FAILURE;
+ goto out;
+ }
+
+ errno = 0;
+ for (size_t i = 0; i < N_ELEMENTS (g_config_table); i++)
+ {
+ const struct config_item *item = g_config_table + i;
+ fprintf (fp, "# %s\n", item->description);
+ if (item->default_value)
+ fprintf (fp, "%s=%s\n", item->key, item->default_value);
+ else
+ fprintf (fp, "#%s=\n", item->key);
+ }
+ fclose (fp);
+ if (errno)
+ {
+ print_fatal ("writing to `%s' failed: %s", path.str, strerror (errno));
+ status = EXIT_FAILURE;
+ goto out;
+ }
+ print_status ("configuration written to `%s'", path.str);
+
+out:
+ str_free (&path);
+ str_free (&base);
+ exit (status);
+}
+
+static void
+print_usage (const char *program_name)
+{
+ fprintf (stderr,
+ "Usage: %s [OPTION]...\n"
+ "Experimental IRC bot.\n"
+ "\n"
+ " -d, --debug run in debug mode\n"
+ " -h, --help display this help and exit\n"
+ " -V, --version output version information and exit\n"
+ " --write-default-cfg [filename]\n"
+ " write a default configuration file and exit\n",
+ program_name);
+}
+
+int
+main (int argc, char *argv[])
+{
+ const char *invocation_name = argv[0];
+ str_vector_init (&g_original_argv);
+ str_vector_add_vector (&g_original_argv, argv);
+
+ static struct option opts[] =
+ {
+ { "debug", no_argument, NULL, 'd' },
+ { "help", no_argument, NULL, 'h' },
+ { "version", no_argument, NULL, 'V' },
+ { "write-default-cfg", optional_argument, NULL, 'w' },
+ { NULL, 0, NULL, 0 }
+ };
+
+ while (1)
+ {
+ int c, opt_index;
+
+ c = getopt_long (argc, argv, "dhV", opts, &opt_index);
+ if (c == -1)
+ break;
+
+ switch (c)
+ {
+ case 'd':
+ g_debug_mode = true;
+ break;
+ case 'h':
+ print_usage (invocation_name);
+ exit (EXIT_SUCCESS);
+ case 'V':
+ printf (PROGRAM_NAME " " PROGRAM_VERSION "\n");
+ exit (EXIT_SUCCESS);
+ case 'w':
+ write_default_configuration (optarg);
+ abort ();
+ default:
+ print_fatal ("error in options");
+ exit (EXIT_FAILURE);
+ }
+ }
+
+ print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting");
+ setup_signal_handlers ();
+
+ SSL_library_init ();
+ atexit (EVP_cleanup);
+ SSL_load_error_strings ();
+ atexit (ERR_free_strings);
+
+ struct bot_context ctx;
+ bot_context_init (&ctx);
+
+ struct error *e = NULL;
+ if (!read_config_file (&ctx.config, &e))
+ {
+ print_fatal ("error loading configuration: %s", e->message);
+ error_free (e);
+ exit (EXIT_FAILURE);
+ }
+
+ setup_recovery_handler (&ctx);
+ poller_set (&ctx.poller, g_signal_pipe[0], POLLIN,
+ (poller_dispatcher_func) on_signal_pipe_readable, &ctx);
+
+ plugin_load_all_from_config (&ctx);
+ if (!irc_connect (&ctx, &e))
+ {
+ print_error ("%s", e->message);
+ error_free (e);
+ exit (EXIT_FAILURE);
+ }
+
+ // TODO: clean re-exec support; to save the state I can either use argv,
+ // argp, or I can create a temporary file, unlink it and use the FD
+ // (mkstemp() on a `struct str' constructed from XDG_RUNTIME_DIR, TMPDIR
+ // or /tmp as a last resort + PROGRAM_NAME + ".XXXXXX" -> unlink();
+ // remember to use O_CREAT | O_EXCL). The state needs to be versioned.
+ // Unfortunately I cannot de/serialize SSL state.
+
+ ctx.polling = true;
+ while (ctx.polling)
+ poller_run (&ctx.poller);
+
+ bot_context_free (&ctx);
+ str_vector_free (&g_original_argv);
+ return EXIT_SUCCESS;
+}
+