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Diffstat (limited to 'common.c')
| -rw-r--r-- | common.c | 1988 |
1 files changed, 1988 insertions, 0 deletions
diff --git a/common.c b/common.c new file mode 100644 index 0000000..782572d --- /dev/null +++ b/common.c @@ -0,0 +1,1988 @@ +/* + * common.c: common functionality + * + * 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 <time.h> +#include <limits.h> + +#include <unistd.h> +#include <sys/wait.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <fcntl.h> +#include <poll.h> +#include <signal.h> +#include <strings.h> +#include <regex.h> +#include <libgen.h> +#include <syslog.h> +#include <fnmatch.h> + +#include <sys/socket.h> +#include <sys/types.h> +#include <netinet/in.h> +#include <netdb.h> + +#ifndef NI_MAXHOST +#define NI_MAXHOST 1025 +#endif // ! NI_MAXHOST + +#ifndef NI_MAXSERV +#define NI_MAXSERV 32 +#endif // ! NI_MAXSERV + +#include <getopt.h> +#include <openssl/ssl.h> +#include <openssl/err.h> +#include "siphash.h" + +extern char **environ; + +#ifdef _POSIX_MONOTONIC_CLOCK +#define CLOCK_BEST CLOCK_MONOTONIC +#else // ! _POSIX_MONOTIC_CLOCK +#define CLOCK_BEST CLOCK_REALTIME +#endif // ! _POSIX_MONOTONIC_CLOCK + +#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) + +// --- Logging ----------------------------------------------------------------- + +static void +log_message_syslog (int prio, const char *quote, const char *fmt, va_list ap) +{ + va_list va; + va_copy (va, ap); + int size = vsnprintf (NULL, 0, fmt, va); + va_end (va); + if (size < 0) + return; + + char buf[size + 1]; + if (vsnprintf (buf, sizeof buf, fmt, ap) >= 0) + syslog (prio, "%s%s", quote, buf); +} + +static void +log_message_stdio (int prio, const char *quote, const char *fmt, va_list ap) +{ + (void) prio; + FILE *stream = stderr; + + fputs (quote, stream); + vfprintf (stream, fmt, ap); + fputs ("\n", stream); +} + +static void (*g_log_message_real) (int, const char *, const char *, va_list) + = log_message_stdio; + +static void +log_message (int priority, const char *quote, const char *fmt, ...) + ATTRIBUTE_PRINTF (3, 4); + +static void +log_message (int priority, const char *quote, const char *fmt, ...) +{ + va_list ap; + va_start (ap, fmt); + g_log_message_real (priority, quote, fmt, ap); + va_end (ap); +} + +// `fatal' is reserved for unexpected failures that would harm further operation + +#define print_fatal(...) log_message (LOG_ERR, "fatal: ", __VA_ARGS__) +#define print_error(...) log_message (LOG_ERR, "error: ", __VA_ARGS__) +#define print_warning(...) log_message (LOG_WARNING, "warning: ", __VA_ARGS__) +#define print_status(...) log_message (LOG_INFO, "-- ", __VA_ARGS__) + +#define exit_fatal(...) \ + BLOCK_START \ + print_fatal (__VA_ARGS__); \ + exit (EXIT_FAILURE); \ + BLOCK_END + +// --- 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) \ + log_message (LOG_DEBUG, "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) + exit_fatal ("malloc: %s", strerror (errno)); + return p; +} + +static void * +xcalloc (size_t n, size_t m) +{ + void *p = calloc (n, m); + if (!p && n && m) + exit_fatal ("calloc: %s", strerror (errno)); + return p; +} + +static void * +xrealloc (void *o, size_t n) +{ + void *p = realloc (o, n); + if (!p && n) + exit_fatal ("realloc: %s", strerror (errno)); + return p; +} + +static void * +xreallocarray (void *o, size_t n, size_t m) +{ + if (m && n > SIZE_MAX / m) + { + errno = ENOMEM; + exit_fatal ("reallocarray: %s", strerror (errno)); + } + 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 ---------------------------------------------- + +#define LIST_HEADER(type) \ + struct type *next; \ + struct type *prev; + +#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_reset (struct str_vector *self) +{ + str_vector_free (self); + str_vector_init (self); +} + +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 +{ + char *message; ///< Textual description of the event +}; + +static void +error_set (struct error **e, const char *message, ...) ATTRIBUTE_PRINTF (2, 3); + +static void +error_set (struct error **e, const char *message, ...) +{ + if (!e) + return; + + va_list ap; + va_start (ap, message); + int size = vsnprintf (NULL, 0, message, ap); + va_end (ap); + + hard_assert (size >= 0); + + struct error *tmp = xmalloc (sizeof *tmp); + tmp->message = xmalloc (size + 1); + + va_start (ap, message); + size = vsnprintf (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 +{ + LIST_HEADER (str_map_link) + + 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 + + /// Callback that transforms all key values for storage and comparison; + /// has to behave exactly like strxfrm(). + size_t (*key_xfrm) (char *dest, const char *src, size_t n); +}; + +// As long as you don't remove the current entry, you can modify the map. +// Use `link' directly to access the data. + +struct str_map_iter +{ + struct str_map *map; ///< The map we're iterating + size_t next_index; ///< Next table index to search + struct str_map_link *link; ///< Current link +}; + +#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->key_xfrm = 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 void +str_map_iter_init (struct str_map_iter *self, struct str_map *map) +{ + self->map = map; + self->next_index = 0; + self->link = NULL; +} + +static void * +str_map_iter_next (struct str_map_iter *self) +{ + struct str_map *map = self->map; + if (self->link) + self->link = self->link->next; + while (!self->link) + { + if (self->next_index >= map->alloc) + return NULL; + self->link = map->map[self->next_index++]; + } + return self->link->data; +} + +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_real (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_set (struct str_map *self, const char *key, void *value) +{ + if (!self->key_xfrm) + { + str_map_set_real (self, key, value); + return; + } + char tmp[self->key_xfrm (NULL, key, 0) + 1]; + self->key_xfrm (tmp, key, sizeof tmp); + str_map_set_real (self, tmp, value); +} + +static void * +str_map_find_real (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, (const char *) iter + sizeof *iter)) + return iter->data; + return NULL; +} + +static void * +str_map_find (struct str_map *self, const char *key) +{ + if (!self->key_xfrm) + return str_map_find_real (self, key); + + char tmp[self->key_xfrm (NULL, key, 0) + 1]; + self->key_xfrm (tmp, key, sizeof tmp); + return str_map_find_real (self, tmp); +} + +// --- 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 *); +typedef void (*poller_timer_func) (void *); + +#define POLLER_MIN_ALLOC 16 + +struct poller_timer_info +{ + int64_t when; ///< When is the timer to expire + poller_timer_func dispatcher; ///< Event dispatcher + void *user_data; ///< User data +}; + +struct poller_timers +{ + struct poller_timer_info *info; ///< Min-heap of timers + size_t len; ///< Number of scheduled timers + size_t alloc; ///< Number of timers allocated +}; + +static void +poller_timers_init (struct poller_timers *self) +{ + self->alloc = POLLER_MIN_ALLOC; + self->len = 0; + self->info = xmalloc (self->alloc * sizeof *self->info); +} + +static void +poller_timers_free (struct poller_timers *self) +{ + free (self->info); +} + +static int64_t +poller_timers_get_current_time (void) +{ +#ifdef _POSIX_TIMERS + struct timespec tp; + hard_assert (clock_gettime (CLOCK_BEST, &tp) != -1); + return (int64_t) tp.tv_sec * 1000 + (int64_t) tp.tv_nsec / 1000000; +#else + struct timeval tp; + gettimeofday (&tp, NULL); + return (int64_t) tp.tv_sec * 1000 + (int64_t) tp.tv_usec / 1000; +#endif +} + +static void +poller_timers_heapify_down (struct poller_timers *self, size_t index) +{ + typedef struct poller_timer_info info_t; + info_t *end = self->info + self->len; + + while (true) + { + info_t *parent = self->info + index; + info_t *left = self->info + 2 * index + 1; + info_t *right = self->info + 2 * index + 2; + + info_t *largest = parent; + if (left < end && left->when > largest->when) + largest = left; + if (right < end && right->when > largest->when) + largest = right; + if (parent == largest) + break; + + info_t tmp = *parent; + *parent = *largest; + *largest = tmp; + + index = largest - self->info; + } +} + +static void +poller_timers_remove_at_index (struct poller_timers *self, size_t index) +{ + hard_assert (index < self->len); + if (index == --self->len) + return; + + self->info[index] = self->info[self->len]; + poller_timers_heapify_down (self, index); +} + +static void +poller_timers_dispatch (struct poller_timers *self) +{ + int64_t now = poller_timers_get_current_time (); + while (self->len && self->info->when <= now) + { + struct poller_timer_info info = *self->info; + poller_timers_remove_at_index (self, 0); + info.dispatcher (info.user_data); + } +} + +static void +poller_timers_heapify_up (struct poller_timers *self, size_t index) +{ + while (index != 0) + { + size_t parent = (index - 1) / 2; + if (self->info[parent].when <= self->info[index].when) + break; + + struct poller_timer_info tmp = self->info[parent]; + self->info[parent] = self->info[index]; + self->info[index] = tmp; + + index = parent; + } +} + +static ssize_t +poller_timers_find (struct poller_timers *self, + poller_timer_func dispatcher, void *data) +{ + // NOTE: there may be duplicates. + for (size_t i = 0; i < self->len; i++) + if (self->info[i].dispatcher == dispatcher + && self->info[i].user_data == data) + return i; + return -1; +} + +static ssize_t +poller_timers_find_by_data (struct poller_timers *self, void *data) +{ + for (size_t i = 0; i < self->len; i++) + if (self->info[i].user_data == data) + return i; + return -1; +} + +static void +poller_timers_add (struct poller_timers *self, + poller_timer_func dispatcher, void *data, int timeout_ms) +{ + if (self->len == self->alloc) + self->info = xreallocarray (self->info, + self->alloc <<= 1, sizeof *self->info); + + self->info[self->len] = (struct poller_timer_info) { + .when = poller_timers_get_current_time () + timeout_ms, + .dispatcher = dispatcher, .user_data = data }; + poller_timers_heapify_up (self, self->len++); +} + +static int +poller_timers_get_poll_timeout (struct poller_timers *self) +{ + if (!self->len) + return -1; + + int64_t timeout = self->info->when - poller_timers_get_current_time (); + if (timeout <= 0) + return 0; + if (timeout > INT_MAX) + return INT_MAX; + return timeout; +} + +#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 + short events; ///< The poll() events we registered for + 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 + + struct poller_timers timers; ///< Timeouts + + /// Index of the element in `revents' that's about to be dispatched next. + int dispatch_next; + + /// 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); + + poller_timers_init (&self->timers); + + self->dispatch_next = 0; + 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); + } + + poller_timers_free (&self->timers); + + 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; + hard_assert (self->alloc != 0); + + self->revents = xreallocarray + (self->revents, sizeof *self->revents, self->alloc); + self->info = xreallocarray + (self->info, sizeof *self->info, self->alloc); +} + +static short +poller_epoll_to_poll_events (uint32_t events) +{ + short 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 (short 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 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->events = events; + 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_total) + return; + + int i; + for (i = self->dispatch_next; 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]; +} + +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_total); + + int n_fds; + do + n_fds = epoll_wait (self->epoll_fd, self->revents, self->len, + poller_timers_get_poll_timeout (&self->timers)); + while (n_fds == -1 && errno == EINTR); + + if (n_fds == -1) + exit_fatal ("%s: %s", "epoll", strerror (errno)); + + poller_timers_dispatch (&self->timers); + + self->dispatch_next = 0; + self->dispatch_total = n_fds; + + while (self->dispatch_next < self->dispatch_total) + { + struct epoll_event *revents = self->revents + self->dispatch_next; + 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 = info->events; + + self->dispatch_next++; + info->dispatcher (&pfd, info->user_data); + } + + self->dispatch_next = 0; + 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 + + struct poller_timers timers; ///< Timers + int dispatch_next; ///< The next 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); + poller_timers_init (&self->timers); + self->dispatch_next = -1; +} + +static void +poller_free (struct poller *self) +{ + free (self->fds); + free (self->fds_info); + poller_timers_free (&self->timers); +} + +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 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_next) + { + 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); + self->dispatch_next--; + } + else + { + self->fds[index] = self->fds[self->len]; + self->fds_info[index] = self->fds_info[self->len]; + } +} + +static void +poller_run (struct poller *self) +{ + // Not reentrant + hard_assert (self->dispatch_next == -1); + + int result; + do + result = poll (self->fds, self->len, + poller_timers_get_poll_timeout (&self->timers)); + while (result == -1 && errno == EINTR); + + if (result == -1) + exit_fatal ("%s: %s", "poll", strerror (errno)); + + poller_timers_dispatch (&self->timers); + + for (int i = 0; i < (int) self->len; ) + { + struct pollfd pfd = self->fds[i]; + if (!pfd.revents) + continue; + + struct poller_info *info = self->fds_info + i; + self->dispatch_next = ++i; + info->dispatcher (&pfd, info->user_data); + i = self->dispatch_next; + } + + self->dispatch_next = -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 char * +join_str_vector (const struct str_vector *v, char delimiter) +{ + if (!v->len) + return xstrdup (""); + + struct str result; + str_init (&result); + str_append (&result, v->vector[0]); + for (size_t i = 1; i < v->len; i++) + str_append_printf (&result, "%c%s", delimiter, v->vector[i]); + return str_steal (&result); +} + +static char *xstrdup_printf (const char *, ...) ATTRIBUTE_PRINTF (1, 2); + +static char * +xstrdup_printf (const char *format, ...) +{ + va_list ap; + struct str tmp; + str_init (&tmp); + va_start (ap, format); + str_append_vprintf (&tmp, format, ap); + va_end (ap); + return str_steal (&tmp); +} + +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 void +get_xdg_config_dirs (struct str_vector *out) +{ + struct str config_home; + str_init (&config_home); + get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config"); + str_vector_add (out, config_home.str); + str_free (&config_home); + + const char *xdg_config_dirs; + if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS"))) + split_str_ignore_empty (xdg_config_dirs, ':', out); +} + +static char * +resolve_config_filename (const char *filename) +{ + // Absolute path is absolute + if (*filename == '/') + return xstrdup (filename); + + struct str_vector paths; + str_vector_init (&paths); + get_xdg_config_dirs (&paths); + + struct str file; + str_init (&file); + + char *result = NULL; + for (unsigned i = 0; i < paths.len; i++) + { + // As per spec, relative paths are ignored + if (*paths.vector[i] != '/') + continue; + + str_reset (&file); + str_append_printf (&file, "%s/" PROGRAM_NAME "/%s", + paths.vector[i], filename); + + struct stat st; + if (!stat (file.str, &st)) + { + result = str_steal (&file); + break; + } + } + + str_vector_free (&paths); + str_free (&file); + return result; +} + +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, "cannot create directory `%s': %s", + path, strerror (errno)); + return false; + } + } + else if (!S_ISDIR (st.st_mode)) + { + error_set (e, "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 bool +xstrtoul (unsigned long *out, const char *s, int base) +{ + char *end; + errno = 0; + *out = strtoul (s, &end, base); + return errno == 0 && !*end && end != s; +} + +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; +} + +#define XSSL_ERROR_TRY_AGAIN INT_MAX + +/// A small wrapper around SSL_get_error() to simplify further handling +static int +xssl_get_error (SSL *ssl, int result, const char **error_info) +{ + int error = SSL_get_error (ssl, result); + switch (error) + { + case SSL_ERROR_NONE: + case SSL_ERROR_ZERO_RETURN: + case SSL_ERROR_WANT_READ: + case SSL_ERROR_WANT_WRITE: + return error; + case SSL_ERROR_SYSCALL: + if ((error = ERR_get_error ())) + *error_info = ERR_error_string (error, NULL); + else if (result == 0) + // An EOF that's not according to the protocol is still an EOF + return SSL_ERROR_ZERO_RETURN; + else + { + if (errno == EINTR) + return XSSL_ERROR_TRY_AGAIN; + *error_info = strerror (errno); + } + return SSL_ERROR_SSL; + default: + if ((error = ERR_get_error ())) + *error_info = ERR_error_string (error, NULL); + else + *error_info = "Unknown error"; + return SSL_ERROR_SSL; + } +} + +// --- Regular expressions ----------------------------------------------------- + +static regex_t * +regex_compile (const char *regex, int flags, struct error **e) +{ + regex_t *re = xmalloc (sizeof *re); + int err = regcomp (re, regex, flags); + if (!err) + return re; + + char buf[regerror (err, re, NULL, 0)]; + regerror (err, re, buf, sizeof buf); + + free (re); + error_set (e, "%s: %s", "failed to compile regular expression", buf); + return NULL; +} + +static void +regex_free (void *regex) +{ + regfree (regex); + free (regex); +} + +// The cost of hashing a string is likely to be significantly smaller than that +// of compiling the whole regular expression anew, so here is a simple cache. +// Adding basic support for subgroups is easy: check `re_nsub' and output into +// a `struct str_vector' (if all we want is the substrings). + +static void +regex_cache_init (struct str_map *cache) +{ + str_map_init (cache); + cache->free = regex_free; +} + +static bool +regex_cache_match (struct str_map *cache, const char *regex, int flags, + const char *s, struct error **e) +{ + regex_t *re = str_map_find (cache, regex); + if (!re) + { + re = regex_compile (regex, flags, e); + if (!re) + return false; + str_map_set (cache, regex, re); + } + return regexec (re, s, 0, NULL, 0) != REG_NOMATCH; +} + +// --- IRC utilities ----------------------------------------------------------- + +struct irc_message +{ + struct str_map tags; ///< IRC 3.2 message tags + char *prefix; ///< Message prefix + char *command; ///< IRC command + struct str_vector params; ///< Command parameters +}; + +static void +irc_parse_message_tags (const char *tags, struct str_map *out) +{ + struct str_vector v; + str_vector_init (&v); + split_str_ignore_empty (tags, ';', &v); + + for (size_t i = 0; i < v.len; i++) + { + char *key = v.vector[i], *equal_sign = strchr (key, '='); + if (equal_sign) + { + *equal_sign = '\0'; + str_map_set (out, key, xstrdup (equal_sign + 1)); + } + else + str_map_set (out, key, xstrdup ("")); + } + + str_vector_free (&v); +} + +static void +irc_parse_message (struct irc_message *msg, const char *line) +{ + str_map_init (&msg->tags); + msg->tags.free = free; + + msg->prefix = NULL; + msg->command = NULL; + str_vector_init (&msg->params); + + // IRC 3.2 message tags + if (*line == '@') + { + size_t tags_len = strcspn (++line, " "); + char *tags = xstrndup (line, tags_len); + irc_parse_message_tags (tags, &msg->tags); + free (tags); + + line += tags_len; + while (*line == ' ') + line++; + } + + // 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) +{ + str_map_free (&msg->tags); + 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, *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; + } + + // XXX: we might want to just advance some kind of an offset to avoid + // moving memory around unnecessarily. + str_remove_slice (buf, 0, start - buf->str); +} + +static int +irc_tolower (int c) +{ + if (c == '[') return '{'; + if (c == ']') return '}'; + if (c == '\\') return '|'; + if (c == '~') return '^'; + return c >= 'A' && c <= 'Z' ? c + ('a' - 'A') : c; +} + +static size_t +irc_strxfrm (char *dest, const char *src, size_t n) +{ + size_t len = strlen (src); + while (n-- && (*dest++ = irc_tolower (*src++))) + ; + return len; +} + +static int +irc_strcmp (const char *a, const char *b) +{ + int x; + while (*a || *b) + if ((x = irc_tolower (*a++) - irc_tolower (*b++))) + return x; + return 0; +} + +static int +irc_fnmatch (const char *pattern, const char *string) +{ + size_t pattern_size = strlen (pattern) + 1; + size_t string_size = strlen (string) + 1; + char x_pattern[pattern_size], x_string[string_size]; + irc_strxfrm (x_pattern, pattern, pattern_size); + irc_strxfrm (x_string, string, string_size); + return fnmatch (x_pattern, x_string, 0); +} + +// --- Configuration ----------------------------------------------------------- + +// The keys are stripped of surrounding whitespace, the values are not. + +struct config_item +{ + const char *key; + const char *default_value; + const char *description; +}; + +static void +load_config_defaults (struct str_map *config, const struct config_item *table) +{ + for (; table->key != NULL; table++) + if (table->default_value) + str_map_set (config, table->key, xstrdup (table->default_value)); + else + str_map_set (config, table->key, NULL); +} + +static bool +read_config_file (struct str_map *config, struct error **e) +{ + char *filename = resolve_config_filename (PROGRAM_NAME ".conf"); + if (!filename) + return true; + + FILE *fp = fopen (filename, "r"); + if (!fp) + { + error_set (e, "could not open `%s' for reading: %s", + filename, strerror (errno)); + return false; + } + + struct str line; + str_init (&line); + + bool errors = false; + for (unsigned 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) + { + char *value = end + 1; + do + *end = '\0'; + while (isspace (*--end)); + + str_map_set (config, start, xstrdup (value)); + } + else if (*start) + { + error_set (e, "line %u in config: %s", line_no, "malformed input"); + errors = true; + break; + } + } + + str_free (&line); + fclose (fp); + return !errors; +} + +static char * +write_default_config (const char *filename, const char *prolog, + const struct config_item *table, struct error **e) +{ + struct str path, base; + + 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"); + } + + if (!mkdir_with_parents (path.str, e)) + goto error; + + str_append_c (&path, '/'); + str_append_str (&path, &base); + + FILE *fp = fopen (path.str, "w"); + if (!fp) + { + error_set (e, "could not open `%s' for writing: %s", + path.str, strerror (errno)); + goto error; + } + + if (prolog) + fputs (prolog, fp); + + errno = 0; + for (; table->key != NULL; table++) + { + fprintf (fp, "# %s\n", table->description); + if (table->default_value) + fprintf (fp, "%s=%s\n", table->key, table->default_value); + else + fprintf (fp, "#%s=\n", table->key); + } + fclose (fp); + if (errno) + { + error_set (e, "writing to `%s' failed: %s", path.str, strerror (errno)); + goto error; + } + + str_free (&base); + return str_steal (&path); + +error: + str_free (&base); + str_free (&path); + return NULL; + +} + +static void +call_write_default_config (const char *hint, const struct config_item *table) +{ + static const char *prolog = + "# " PROGRAM_NAME " " PROGRAM_VERSION " configuration file\n" + "#\n" + "# Relative paths are searched for in ${XDG_CONFIG_HOME:-~/.config}\n" + "# /" PROGRAM_NAME " as well as in $XDG_CONFIG_DIRS/" PROGRAM_NAME "\n" + "\n"; + + struct error *e = NULL; + char *filename = write_default_config (hint, prolog, table, &e); + if (!filename) + { + print_error ("%s", e->message); + error_free (e); + exit (EXIT_FAILURE); + } + print_status ("configuration written to `%s'", filename); + free (filename); +} |