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-rw-r--r--xB.c2063
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diff --git a/xB.c b/xB.c
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+++ b/xB.c
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+/*
+ * xB.c: a modular IRC bot
+ *
+ * Copyright (c) 2014 - 2020, Přemysl Eric Janouch <p@janouch.name>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted.
+ *
+ * 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.
+ *
+ */
+
+#include "config.h"
+#define PROGRAM_NAME "xB"
+
+#include "common.c"
+
+// --- Configuration (application-specific) ------------------------------------
+
+static struct simple_config_item g_config_table[] =
+{
+ { "nickname", "xB", "IRC nickname" },
+ { "username", "bot", "IRC user name" },
+ { "realname", "xB IRC bot", "IRC real name/e-mail" },
+
+ { "irc_host", NULL, "Address of the IRC server" },
+ { "irc_port", "6667", "Port of the IRC server" },
+ { "tls", "off", "Whether to use TLS" },
+ { "tls_cert", NULL, "Client TLS certificate (PEM)" },
+ { "tls_verify", "on", "Whether to verify certificates" },
+ { "tls_ca_file", NULL, "OpenSSL CA bundle file" },
+ { "tls_ca_path", NULL, "OpenSSL CA bundle path" },
+ { "autojoin", NULL, "Channels to join on start" },
+ { "reconnect", "on", "Whether to reconnect on error" },
+ { "reconnect_delay", "5", "Time between reconnecting" },
+
+ { "socks_host", NULL, "Address of a SOCKS 4a/5 proxy" },
+ { "socks_port", "1080", "SOCKS port number" },
+ { "socks_username", NULL, "SOCKS auth. username" },
+ { "socks_password", NULL, "SOCKS auth. password" },
+
+ { "prefix", ":", "The prefix for bot commands" },
+ { "admin", NULL, "Host mask for administrators" },
+ { "plugins", NULL, "The plugins to load on startup" },
+ { "plugin_dir", NULL, "Plugin search path override" },
+ { "recover", "on", "Whether to re-launch on crash" },
+
+ { NULL, NULL, NULL }
+};
+
+// --- Application data --------------------------------------------------------
+
+struct plugin
+{
+ LIST_HEADER (struct plugin)
+ struct bot_context *ctx; ///< Parent context
+
+ char *name; ///< Plugin identifier
+ pid_t pid; ///< PID of the plugin process
+
+ 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
+ int write_fd; ///< The write end of the comm. pipe
+
+ struct poller_fd read_event; ///< Read FD event
+ struct poller_fd write_event; ///< Write FD event
+
+ struct str read_buffer; ///< Unprocessed input
+ struct str write_buffer; ///< Output yet to be sent out
+};
+
+static struct plugin *
+plugin_new (void)
+{
+ struct plugin *self = xcalloc (1, sizeof *self);
+ self->pid = -1;
+ self->queued_output = str_make ();
+
+ self->read_fd = -1;
+ self->read_buffer = str_make ();
+ self->write_fd = -1;
+ self->write_buffer = str_make ();
+ return self;
+}
+
+static void
+plugin_destroy (struct plugin *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);
+
+ free (self);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+struct bot_context
+{
+ struct str_map config; ///< User configuration
+ regex_t *admin_re; ///< Regex to match our administrator
+ bool reconnect; ///< Whether to reconnect on conn. fail.
+ unsigned long reconnect_delay; ///< Reconnect delay in seconds
+
+ int irc_fd; ///< Socket FD of the server
+ struct str read_buffer; ///< Input yet to be processed
+ struct poller_fd irc_event; ///< IRC FD event
+ bool irc_registered; ///< Whether we may send messages now
+
+ struct poller_fd signal_event; ///< Signal FD event
+ struct poller_timer ping_tmr; ///< We should send a ping
+ struct poller_timer timeout_tmr; ///< Connection seems to be dead
+ struct poller_timer reconnect_tmr; ///< We should reconnect now
+
+ SSL_CTX *ssl_ctx; ///< SSL context
+ SSL *ssl; ///< SSL connection
+
+ struct plugin *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 on_irc_ping_timeout (void *user_data);
+static void on_irc_timeout (void *user_data);
+static void on_irc_reconnect_timeout (void *user_data);
+
+static void
+bot_context_init (struct bot_context *self)
+{
+ self->config = str_map_make (free);
+ simple_config_load_defaults (&self->config, g_config_table);
+ self->admin_re = NULL;
+
+ self->irc_fd = -1;
+ self->read_buffer = str_make ();
+ self->irc_registered = false;
+
+ self->ssl = NULL;
+ self->ssl_ctx = NULL;
+
+ self->plugins = NULL;
+ self->plugins_by_name = str_map_make (NULL);
+
+ poller_init (&self->poller);
+ self->quitting = false;
+ self->polling = false;
+
+ self->timeout_tmr = poller_timer_make (&self->poller);
+ self->timeout_tmr.dispatcher = on_irc_timeout;
+ self->timeout_tmr.user_data = self;
+
+ self->ping_tmr = poller_timer_make (&self->poller);
+ self->ping_tmr.dispatcher = on_irc_ping_timeout;
+ self->ping_tmr.user_data = self;
+
+ self->reconnect_tmr = poller_timer_make (&self->poller);
+ self->reconnect_tmr.dispatcher = on_irc_reconnect_timeout;
+ self->reconnect_tmr.user_data = self;
+}
+
+static void
+bot_context_free (struct bot_context *self)
+{
+ str_map_free (&self->config);
+ if (self->admin_re)
+ regex_free (self->admin_re);
+ str_free (&self->read_buffer);
+
+ // TODO: terminate the plugins properly before this is called
+ LIST_FOR_EACH (struct plugin, link, self->plugins)
+ plugin_destroy (link);
+
+ if (self->irc_fd != -1)
+ {
+ poller_fd_reset (&self->irc_event);
+ xclose (self->irc_fd);
+ }
+ if (self->ssl)
+ SSL_free (self->ssl);
+ if (self->ssl_ctx)
+ SSL_CTX_free (self->ssl_ctx);
+
+ str_map_free (&self->plugins_by_name);
+ poller_free (&self->poller);
+}
+
+static void
+irc_shutdown (struct bot_context *ctx)
+{
+ // TODO: set a timer after which we cut the connection?
+ // 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
+try_finish_quit (struct bot_context *ctx)
+{
+ if (ctx->quitting && ctx->irc_fd == -1 && !ctx->plugins)
+ ctx->polling = false;
+}
+
+static bool plugin_zombify (struct plugin *);
+
+static void
+initiate_quit (struct bot_context *ctx)
+{
+ // Initiate bringing down of the two things that block our shutdown:
+ // a/ the IRC socket, b/ our child processes:
+
+ for (struct plugin *plugin = ctx->plugins;
+ plugin; plugin = plugin->next)
+ plugin_zombify (plugin);
+ if (ctx->irc_fd != -1)
+ irc_shutdown (ctx);
+
+ ctx->quitting = true;
+ try_finish_quit (ctx);
+}
+
+static bool irc_send (struct bot_context *ctx,
+ const char *format, ...) ATTRIBUTE_PRINTF (2, 3);
+
+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);
+ }
+
+ if (!soft_assert (ctx->irc_fd != -1))
+ return false;
+
+ va_start (ap, format);
+ struct str str = str_make ();
+ 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
+ ERR_clear_error ();
+ if (SSL_write (ctx->ssl, str.str, str.len) != (int) str.len)
+ {
+ print_debug ("%s: %s: %s", __func__, "SSL_write",
+ xerr_describe_error ());
+ 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_get_boolean_from_config
+ (struct bot_context *ctx, const char *name, bool *value, struct error **e)
+{
+ const char *str = str_map_find (&ctx->config, name);
+ hard_assert (str != NULL);
+
+ if (set_boolean_if_valid (value, str))
+ return true;
+
+ return error_set (e, "invalid configuration value for `%s'", name);
+}
+
+static bool
+irc_initialize_ca_set (SSL_CTX *ssl_ctx, const char *file, const char *path,
+ struct error **e)
+{
+ ERR_clear_error ();
+
+ if (file || path)
+ {
+ if (SSL_CTX_load_verify_locations (ssl_ctx, file, path))
+ return true;
+
+ return error_set (e, "%s: %s",
+ "failed to set locations for the CA certificate bundle",
+ xerr_describe_error ());
+ }
+
+ if (!SSL_CTX_set_default_verify_paths (ssl_ctx))
+ return error_set (e, "%s: %s",
+ "couldn't load the default CA certificate bundle",
+ xerr_describe_error ());
+ return true;
+}
+
+static bool
+irc_initialize_ca (struct bot_context *ctx, struct error **e)
+{
+ const char *ca_file = str_map_find (&ctx->config, "tls_ca_file");
+ const char *ca_path = str_map_find (&ctx->config, "tls_ca_path");
+
+ char *full_file = ca_file
+ ? resolve_filename (ca_file, resolve_relative_config_filename) : NULL;
+ char *full_path = ca_path
+ ? resolve_filename (ca_path, resolve_relative_config_filename) : NULL;
+
+ bool ok = false;
+ if (ca_file && !full_file)
+ error_set (e, "couldn't find the CA bundle file");
+ else if (ca_path && !full_path)
+ error_set (e, "couldn't find the CA bundle path");
+ else
+ ok = irc_initialize_ca_set (ctx->ssl_ctx, full_file, full_path, e);
+
+ free (full_file);
+ free (full_path);
+ return ok;
+}
+
+static bool
+irc_initialize_ssl_ctx (struct bot_context *ctx, struct error **e)
+{
+ // Disable deprecated protocols (see RFC 7568)
+ SSL_CTX_set_options (ctx->ssl_ctx, SSL_OP_NO_SSLv2 | SSL_OP_NO_SSLv3);
+
+ bool verify;
+ if (!irc_get_boolean_from_config (ctx, "tls_verify", &verify, e))
+ return false;
+ SSL_CTX_set_verify (ctx->ssl_ctx,
+ verify ? SSL_VERIFY_PEER : SSL_VERIFY_NONE, NULL);
+
+ struct error *error = NULL;
+ if (!irc_initialize_ca (ctx, &error))
+ {
+ if (verify)
+ {
+ error_propagate (e, error);
+ return false;
+ }
+
+ // Only inform the user if we're not actually verifying
+ print_warning ("%s", error->message);
+ error_free (error);
+ }
+ return true;
+}
+
+static bool
+irc_initialize_tls (struct bot_context *ctx, struct error **e)
+{
+ const char *error_info = NULL;
+ ctx->ssl_ctx = SSL_CTX_new (SSLv23_client_method ());
+ if (!ctx->ssl_ctx)
+ goto error_ssl_1;
+ if (!irc_initialize_ssl_ctx (ctx, e))
+ goto error_ssl_2;
+
+ ctx->ssl = SSL_new (ctx->ssl_ctx);
+ if (!ctx->ssl)
+ goto error_ssl_2;
+
+ const char *tls_cert = str_map_find (&ctx->config, "tls_cert");
+ if (tls_cert)
+ {
+ char *path = resolve_filename
+ (tls_cert, resolve_relative_config_filename);
+ if (!path)
+ print_error ("%s: %s", "cannot open file", tls_cert);
+ // XXX: perhaps we should read the file ourselves for better messages
+ else if (!SSL_use_certificate_file (ctx->ssl, path, SSL_FILETYPE_PEM)
+ || !SSL_use_PrivateKey_file (ctx->ssl, path, SSL_FILETYPE_PEM))
+ print_error ("%s: %s", "setting the TLS client certificate failed",
+ xerr_describe_error ());
+ free (path);
+ }
+
+ 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);
+
+ switch (xssl_get_error (ctx->ssl, SSL_connect (ctx->ssl), &error_info))
+ {
+ case SSL_ERROR_NONE:
+ return true;
+ case SSL_ERROR_ZERO_RETURN:
+ error_info = "server closed the connection";
+ default:
+ break;
+ }
+
+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:
+ if (!error_info)
+ error_info = xerr_describe_error ();
+ return error_set (e, "%s: %s", "could not initialize TLS", error_info);
+}
+
+static bool
+irc_establish_connection (struct bot_context *ctx,
+ const char *host, const char *port, struct error **e)
+{
+ struct addrinfo gai_hints, *gai_result, *gai_iter;
+ memset (&gai_hints, 0, sizeof gai_hints);
+ gai_hints.ai_socktype = SOCK_STREAM;
+
+ int err = getaddrinfo (host, port, &gai_hints, &gai_result);
+ if (err)
+ return error_set (e, "%s: %s: %s", "connection failed",
+ "getaddrinfo", gai_strerror (err));
+
+ 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!
+ char *address = format_host_port_pair (real_host, port);
+ print_status ("connecting to %s...", address);
+ free (address);
+
+ if (!connect (sockfd, gai_iter->ai_addr, gai_iter->ai_addrlen))
+ break;
+
+ xclose (sockfd);
+ }
+
+ freeaddrinfo (gai_result);
+
+ if (!gai_iter)
+ return error_set (e, "connection failed");
+
+ ctx->irc_fd = sockfd;
+ return true;
+}
+
+// --- Signals -----------------------------------------------------------------
+
+static int g_signal_pipe[2]; ///< A pipe used to signal... signals
+
+static struct strv
+ 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)
+ exit_fatal ("%s: %s", "pipe", strerror (errno));
+
+ 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)
+ exit_fatal ("sigaction: %s", strerror (errno));
+
+ signal (SIGPIPE, SIG_IGN);
+
+ sa.sa_handler = sigterm_handler;
+ if (sigaction (SIGINT, &sa, NULL) == -1
+ || sigaction (SIGTERM, &sa, NULL) == -1)
+ exit_fatal ("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;
+
+ // Avoid annoying resource intensive infinite loops by sleeping for a bit
+ (void) sleep (1);
+
+ // 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)
+{
+ g_recovery_env = strv_make ();
+ strv_append_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
+ {
+ g_startup_reason_location = g_recovery_env.vector + g_recovery_env.len;
+ strv_append (&g_recovery_env, "");
+ }
+}
+
+static bool
+setup_recovery_handler (struct bot_context *ctx, struct error **e)
+{
+ bool recover;
+ if (!irc_get_boolean_from_config (ctx, "recover", &recover, e))
+ return false;
+ if (!recover)
+ return true;
+
+ // 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));
+ return true;
+}
+
+// --- Plugins -----------------------------------------------------------------
+
+/// The name of the special IRC command for interprocess communication
+static const char *plugin_ipc_command = "ZYKLONB";
+
+static struct plugin *
+plugin_find_by_pid (struct bot_context *ctx, pid_t pid)
+{
+ struct plugin *iter;
+ for (iter = ctx->plugins; iter; iter = iter->next)
+ if (iter->pid == pid)
+ return iter;
+ return NULL;
+}
+
+static bool
+plugin_zombify (struct plugin *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).
+ poller_fd_reset (&plugin->write_event);
+
+ // 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;
+
+ // TODO: wait a few seconds and then send SIGKILL to the plugin
+ return true;
+}
+
+static void
+on_plugin_writable (const struct pollfd *fd, struct plugin *plugin)
+{
+ struct str *buf = &plugin->write_buffer;
+ size_t written_total = 0;
+
+ if (fd->revents & ~(POLLOUT | POLLHUP | POLLERR))
+ print_debug ("fd %d: unexpected 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 (errno == EINTR)
+ continue;
+
+ soft_assert (errno == EPIPE);
+ // Zombies shouldn't get dispatched for writability
+ hard_assert (!plugin->is_zombie);
+
+ print_debug ("%s: %s", "write", 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
+ poller_fd_reset (&plugin->write_event);
+}
+
+static void
+plugin_queue_write (struct plugin *plugin)
+{
+ if (plugin->is_zombie)
+ return;
+
+ // Don't let the write buffer grow indefinitely. 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_fd_set (&plugin->write_event, POLLOUT);
+}
+
+static void
+plugin_send (struct plugin *plugin, const char *format, ...)
+ ATTRIBUTE_PRINTF (2, 3);
+
+static void
+plugin_send (struct plugin *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_ipc (struct plugin *plugin, const struct irc_message *msg)
+{
+ // 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 (!plugin->initialized && !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 (&plugin->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\n", msg->params.vector[1]);
+ }
+}
+
+static void
+plugin_process_message (const struct irc_message *msg,
+ const char *raw, void *user_data)
+{
+ struct plugin *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))
+ plugin_process_ipc (plugin, msg);
+ else if (plugin->initialized && ctx->irc_registered)
+ {
+ // Pass everything else through to the IRC server
+ // XXX: when the server isn't ready yet, these messages get silently
+ // discarded, which shouldn't pose a problem most of the time.
+ // Perhaps we could send a "connected" notification on `register'
+ // if `irc_ready' is true, or after it becomes true later, so that
+ // plugins know when to start sending unprovoked IRC messages.
+ // XXX: another case is when the connection gets interrupted and the
+ // plugin tries to send something back while we're reconnecting.
+ // For that we might set up a global buffer that gets flushed out
+ // after `irc_ready' becomes true. Note that there is always some
+ // chance of messages getting lost without us even noticing it.
+ irc_send (ctx, "%s", raw);
+ }
+}
+
+static void
+on_plugin_readable (const struct pollfd *fd, struct plugin *plugin)
+{
+ if (fd->revents & ~(POLLIN | POLLHUP | POLLERR))
+ print_debug ("fd %d: unexpected 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_reserve (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;
+ }
+ }
+
+ 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 char *
+plugin_resolve_relative_filename (const char *filename)
+{
+ struct strv paths = strv_make ();
+ get_xdg_data_dirs (&paths);
+ char *result = resolve_relative_filename_generic
+ (&paths, PROGRAM_NAME "/plugins/", filename);
+ strv_free (&paths);
+ return result;
+}
+
+static struct plugin *
+plugin_launch (struct bot_context *ctx, const char *name, struct error **e)
+{
+ char *path = NULL;
+ const char *plugin_dir = str_map_find (&ctx->config, "plugin_dir");
+ if (plugin_dir)
+ {
+ // resolve_relative_filename_generic() won't accept relative paths,
+ // so just keep the old behaviour and expect the file to exist.
+ // We could use resolve_filename() on "plugin_dir" with paths=getcwd().
+ path = xstrdup_printf ("%s/%s", plugin_dir, name);
+ }
+ else if (!(path = plugin_resolve_relative_filename (name)))
+ {
+ error_set (e, "plugin not found");
+ goto fail_0;
+ }
+
+ int stdin_pipe[2];
+ if (pipe (stdin_pipe) == -1)
+ {
+ error_set (e, "%s: %s", "pipe", strerror (errno));
+ goto fail_0;
+ }
+
+ int stdout_pipe[2];
+ if (pipe (stdout_pipe) == -1)
+ {
+ error_set (e, "%s: %s", "pipe", strerror (errno));
+ goto fail_1;
+ }
+
+ struct str work_dir = str_make ();
+ get_xdg_home_dir (&work_dir, "XDG_DATA_HOME", ".local/share");
+ str_append_printf (&work_dir, "/%s", PROGRAM_NAME);
+
+ if (!mkdir_with_parents (work_dir.str, e))
+ goto fail_2;
+
+ set_cloexec (stdin_pipe[1]);
+ set_cloexec (stdout_pipe[0]);
+
+ pid_t pid = fork ();
+ if (pid == -1)
+ {
+ error_set (e, "%s: %s", "fork", strerror (errno));
+ goto fail_2;
+ }
+
+ if (pid == 0)
+ {
+ // Redirect the child's stdin and stdout to the pipes
+ if (dup2 (stdin_pipe[0], STDIN_FILENO) == -1
+ || dup2 (stdout_pipe[1], STDOUT_FILENO) == -1)
+ {
+ print_error ("%s: %s: %s", "failed to load the plugin",
+ "dup2", strerror (errno));
+ _exit (EXIT_FAILURE);
+ }
+ if (chdir (work_dir.str))
+ {
+ print_error ("%s: %s: %s", "failed to load the plugin",
+ "chdir", strerror (errno));
+ _exit (EXIT_FAILURE);
+ }
+
+ xclose (stdin_pipe[0]);
+ xclose (stdout_pipe[1]);
+
+ // Restore some of the signal handling
+ signal (SIGPIPE, SIG_DFL);
+
+ char *argv[] = { path, NULL };
+ execve (argv[0], argv, environ);
+
+ // We will collect the failure later via SIGCHLD
+ print_error ("%s: %s: %s", "failed to load the plugin",
+ "exec", strerror (errno));
+ _exit (EXIT_FAILURE);
+ }
+
+ str_free (&work_dir);
+ free (path);
+
+ xclose (stdin_pipe[0]);
+ xclose (stdout_pipe[1]);
+
+ struct plugin *plugin = plugin_new ();
+ plugin->ctx = ctx;
+ plugin->pid = pid;
+ plugin->name = xstrdup (name);
+ plugin->read_fd = stdout_pipe[0];
+ plugin->write_fd = stdin_pipe[1];
+ return plugin;
+
+fail_2:
+ str_free (&work_dir);
+ xclose (stdout_pipe[0]);
+ xclose (stdout_pipe[1]);
+fail_1:
+ xclose (stdin_pipe[0]);
+ xclose (stdin_pipe[1]);
+fail_0:
+ free (path);
+ return NULL;
+}
+
+static bool
+plugin_load (struct bot_context *ctx, const char *name, struct error **e)
+{
+ if (!is_valid_plugin_name (name))
+ return error_set (e, "invalid plugin name");
+ if (str_map_find (&ctx->plugins_by_name, name))
+ return error_set (e, "the plugin has already been loaded");
+
+ struct plugin *plugin;
+ if (!(plugin = plugin_launch (ctx, name, e)))
+ return false;
+
+ set_blocking (plugin->read_fd, false);
+ set_blocking (plugin->write_fd, false);
+
+ plugin->read_event = poller_fd_make (&ctx->poller, plugin->read_fd);
+ plugin->read_event.dispatcher = (poller_fd_fn) on_plugin_readable;
+ plugin->read_event.user_data = plugin;
+
+ plugin->write_event = poller_fd_make (&ctx->poller, plugin->write_fd);
+ plugin->write_event.dispatcher = (poller_fd_fn) on_plugin_writable;
+ plugin->write_event.user_data = plugin;
+
+ LIST_PREPEND (ctx->plugins, plugin);
+ str_map_set (&ctx->plugins_by_name, name, plugin);
+
+ poller_fd_set (&plugin->read_event, POLLIN);
+ return true;
+}
+
+static bool
+plugin_unload (struct bot_context *ctx, const char *name, struct error **e)
+{
+ struct plugin *plugin = str_map_find (&ctx->plugins_by_name, name);
+
+ if (!plugin)
+ return error_set (e, "no such plugin is loaded");
+
+ plugin_zombify (plugin);
+
+ // TODO: add a `kill zombies' command to forcefully get rid of processes
+ // that do not understand the request.
+ 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 strv plugins = strv_make ();
+ cstr_split (plugin_list, ",", true, &plugins);
+ for (size_t i = 0; i < plugins.len; i++)
+ {
+ char *name = cstr_strip_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);
+ }
+ }
+
+ strv_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 strv *out)
+{
+ cstr_split (arguments, ",", true, out);
+ for (size_t i = 0; i < out->len; )
+ {
+ if (!*cstr_strip_in_place (out->vector[i], " \t"))
+ strv_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)
+{
+ // No administrator set -> everyone is an administrator
+ if (!ctx->admin_re)
+ return true;
+ return regexec (ctx->admin_re, msg->prefix, 0, NULL, 0) != REG_NOMATCH;
+}
+
+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';
+
+ va_list ap;
+ struct str text = str_make ();
+ 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)
+{
+ // XXX: we might want to wait until the plugin terminates before we try
+ // to reload it (so that it can save its configuration or whatever)
+
+ // 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 char *
+make_status_report (struct bot_context *ctx)
+{
+ struct str report = str_make ();
+ const char *reason = getenv (g_startup_reason_str);
+ if (!reason)
+ reason = "launched normally";
+ str_append_printf (&report, "\x02startup reason:\x0f %s", reason);
+
+ size_t zombies = 0;
+ const char *prepend = "; \x02plugins:\x0f ";
+ for (struct plugin *plugin = ctx->plugins; plugin; plugin = plugin->next)
+ {
+ if (plugin->is_zombie)
+ zombies++;
+ else
+ {
+ str_append_printf (&report, "%s%s", prepend, plugin->name);
+ prepend = ", ";
+ }
+ }
+ if (!ctx->plugins)
+ str_append_printf (&report, "%s\x02none\x0f", prepend);
+
+ str_append_printf (&report, "; \x02zombies:\x0f %zu", zombies);
+ return str_steal (&report);
+}
+
+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 strv list = strv_make ();
+
+ 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))
+ {
+ char *report = make_status_report (ctx);
+ respond_to_user (ctx, msg, "%s", report);
+ 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]);
+ }
+
+ strv_free (&list);
+}
+
+static void
+irc_forward_message_to_plugins (struct bot_context *ctx, const char *raw)
+{
+ // For consistency with plugin_process_message()
+ if (!ctx->irc_registered)
+ return;
+
+ for (struct plugin *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);
+ }
+}
+
+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...
+
+ irc_forward_message_to_plugins (ctx, 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_registered && !strcasecmp (msg->command, "001"))
+ {
+ print_status ("successfully connected");
+ ctx->irc_registered = 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_tls (struct bot_context *ctx, struct str *buf)
+{
+ int n_read;
+start:
+ ERR_clear_error ();
+ n_read = SSL_read (ctx->ssl, buf->str + buf->len,
+ buf->alloc - buf->len - 1 /* null byte */);
+
+ const char *error_info = NULL;
+ switch (xssl_get_error (ctx->ssl, n_read, &error_info))
+ {
+ case SSL_ERROR_NONE:
+ buf->str[buf->len += n_read] = '\0';
+ return IRC_READ_OK;
+ 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 XSSL_ERROR_TRY_AGAIN:
+ goto start;
+ default:
+ 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 *, struct error **);
+static void irc_queue_reconnect (struct bot_context *);
+
+static void
+irc_cancel_timers (struct bot_context *ctx)
+{
+ poller_timer_reset (&ctx->timeout_tmr);
+ poller_timer_reset (&ctx->ping_tmr);
+ poller_timer_reset (&ctx->reconnect_tmr);
+}
+
+static void
+on_irc_reconnect_timeout (void *user_data)
+{
+ struct bot_context *ctx = user_data;
+
+ struct error *e = NULL;
+ if (irc_connect (ctx, &e))
+ {
+ // TODO: inform plugins about the new connection
+ return;
+ }
+
+ print_error ("%s", e->message);
+ error_free (e);
+ irc_queue_reconnect (ctx);
+}
+
+static void
+irc_queue_reconnect (struct bot_context *ctx)
+{
+ hard_assert (ctx->irc_fd == -1);
+ print_status ("trying to reconnect in %ld seconds...",
+ ctx->reconnect_delay);
+ poller_timer_set (&ctx->reconnect_tmr, ctx->reconnect_delay * 1000);
+}
+
+static void
+on_irc_disconnected (struct bot_context *ctx)
+{
+ // Get rid of the dead socket and related things
+ if (ctx->ssl)
+ {
+ SSL_free (ctx->ssl);
+ ctx->ssl = NULL;
+ SSL_CTX_free (ctx->ssl_ctx);
+ ctx->ssl_ctx = NULL;
+ }
+
+ poller_fd_reset (&ctx->irc_event);
+ xclose (ctx->irc_fd);
+ ctx->irc_fd = -1;
+ ctx->irc_registered = false;
+
+ // TODO: inform plugins about the disconnect event
+
+ // All of our timers have lost their meaning now
+ irc_cancel_timers (ctx);
+
+ if (ctx->quitting)
+ try_finish_quit (ctx);
+ else if (!ctx->reconnect)
+ initiate_quit (ctx);
+ else
+ irc_queue_reconnect (ctx);
+}
+
+static void
+on_irc_ping_timeout (void *user_data)
+{
+ struct bot_context *ctx = user_data;
+ print_error ("connection timeout");
+ on_irc_disconnected (ctx);
+}
+
+static void
+on_irc_timeout (void *user_data)
+{
+ // Provoke a response from the server
+ struct bot_context *ctx = user_data;
+ irc_send (ctx, "PING :%s",
+ (char *) str_map_find (&ctx->config, "nickname"));
+}
+
+static void
+irc_reset_connection_timeouts (struct bot_context *ctx)
+{
+ irc_cancel_timers (ctx);
+ poller_timer_set (&ctx->timeout_tmr, 3 * 60 * 1000);
+ poller_timer_set (&ctx->ping_tmr, (3 * 60 + 30) * 1000);
+}
+
+static void
+on_irc_readable (const struct pollfd *fd, struct bot_context *ctx)
+{
+ if (fd->revents & ~(POLLIN | POLLHUP | POLLERR))
+ print_debug ("fd %d: unexpected 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_tls
+ : irc_fill_read_buffer;
+ bool disconnected = false;
+ while (true)
+ {
+ str_reserve (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_error ("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);
+ else
+ irc_reset_connection_timeouts (ctx);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+// The bot is currently mostly synchronous (which also makes it shorter),
+// however our current SOCKS code is not, hence we must wrap it.
+
+struct irc_socks_data
+{
+ struct bot_context *ctx; ///< Bot context
+ struct poller inner_poller; ///< Special inner poller
+ bool polling; ///< Inner poller is no longer needed
+ struct socks_connector connector; ///< SOCKS connector
+ bool succeeded; ///< Were we successful in connecting?
+};
+
+static void
+irc_on_socks_connected (void *user_data, int socket, const char *hostname)
+{
+ (void) hostname;
+
+ struct irc_socks_data *data = user_data;
+ data->ctx->irc_fd = socket;
+ data->succeeded = true;
+ data->polling = false;
+}
+
+static void
+irc_on_socks_failure (void *user_data)
+{
+ struct irc_socks_data *data = user_data;
+ data->succeeded = false;
+ data->polling = false;
+}
+
+static void
+irc_on_socks_connecting (void *user_data,
+ const char *address, const char *via, const char *version)
+{
+ (void) user_data;
+ print_status ("connecting to %s via %s (%s)...", address, via, version);
+}
+
+static void
+irc_on_socks_error (void *user_data, const char *error)
+{
+ (void) user_data;
+ print_error ("%s: %s", "SOCKS connection failed", error);
+}
+
+static bool
+irc_establish_connection_socks (struct bot_context *ctx,
+ const char *socks_host, const char *socks_port,
+ const char *host, const char *service, struct error **e)
+{
+ struct irc_socks_data data;
+ struct poller *poller = &data.inner_poller;
+ struct socks_connector *connector = &data.connector;
+
+ data.ctx = ctx;
+ poller_init (poller);
+ data.polling = true;
+ socks_connector_init (connector, poller);
+ data.succeeded = false;
+
+ connector->on_connected = irc_on_socks_connected;
+ connector->on_connecting = irc_on_socks_connecting;
+ connector->on_error = irc_on_socks_error;
+ connector->on_failure = irc_on_socks_failure;
+ connector->user_data = &data;
+
+ if (socks_connector_add_target (connector, host, service, e))
+ {
+ socks_connector_run (connector, socks_host, socks_port,
+ str_map_find (&ctx->config, "socks_username"),
+ str_map_find (&ctx->config, "socks_password"));
+ while (data.polling)
+ poller_run (poller);
+ if (!data.succeeded)
+ error_set (e, "connection failed");
+ }
+
+ socks_connector_free (connector);
+ poller_free (poller);
+ return data.succeeded;
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
+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 *socks_host = str_map_find (&ctx->config, "socks_host");
+ const char *socks_port = str_map_find (&ctx->config, "socks_port");
+
+ const char *nickname = str_map_find (&ctx->config, "nickname");
+ const char *username = str_map_find (&ctx->config, "username");
+ const char *realname = str_map_find (&ctx->config, "realname");
+
+ // We have a default value for these
+ hard_assert (irc_port && socks_port);
+ hard_assert (nickname && username && realname);
+
+ // 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)
+ return error_set (e, "no hostname specified in configuration");
+
+ bool use_tls;
+ if (!irc_get_boolean_from_config (ctx, "tls", &use_tls, e))
+ return false;
+
+ bool connected = socks_host
+ ? irc_establish_connection_socks (ctx,
+ socks_host, socks_port, irc_host, irc_port, e)
+ : irc_establish_connection (ctx, irc_host, irc_port, e);
+ if (!connected)
+ return false;
+
+ if (use_tls && !irc_initialize_tls (ctx, e))
+ {
+ xclose (ctx->irc_fd);
+ ctx->irc_fd = -1;
+ return false;
+ }
+ print_status ("connection established");
+
+ ctx->irc_event = poller_fd_make (&ctx->poller, ctx->irc_fd);
+ ctx->irc_event.dispatcher = (poller_fd_fn) on_irc_readable;
+ ctx->irc_event.user_data = ctx;
+
+ // 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_fd_set (&ctx->irc_event, POLLIN);
+ irc_reset_connection_timeouts (ctx);
+
+ irc_send (ctx, "NICK %s", nickname);
+ irc_send (ctx, "USER %s 8 * :%s", username, realname);
+ return true;
+}
+
+static bool
+parse_config (struct bot_context *ctx, struct error **e)
+{
+ if (!irc_get_boolean_from_config (ctx, "reconnect", &ctx->reconnect, e))
+ return false;
+
+ const char *delay_str = str_map_find (&ctx->config, "reconnect_delay");
+ hard_assert (delay_str != NULL); // We have a default value for this
+ if (!xstrtoul (&ctx->reconnect_delay, delay_str, 10))
+ {
+ return error_set (e,
+ "invalid configuration value for `%s'", "reconnect_delay");
+ }
+
+ hard_assert (!ctx->admin_re);
+ const char *admin = str_map_find (&ctx->config, "admin");
+ if (!admin)
+ return true;
+
+ struct error *error = NULL;
+ ctx->admin_re = regex_compile (admin, REG_EXTENDED | REG_NOSUB, &error);
+ if (!error)
+ return true;
+
+ error_set (e, "invalid configuration value for `%s': %s",
+ "admin", error->message);
+ error_free (error);
+ return false;
+}
+
+static void
+on_plugin_death (struct plugin *plugin, int status)
+{
+ struct bot_context *ctx = plugin->ctx;
+
+ // TODO: callbacks on children death, so that we may tell the user
+ // "plugin `name' died"; use `status'
+ if (!plugin->is_zombie && WIFSIGNALED (status))
+ {
+ const 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;
+
+ // In theory we could close `read_fd', set `read_event->closed' to true
+ // and expect epoll to no longer return events for the descriptor, as
+ // all the pipe ends should be closed by then (the child is dead, so its
+ // pipe FDs have been closed [assuming it hasn't forked without closing
+ // the descriptors, which would be evil], and we would have closed all
+ // of our FDs for this pipe as well). In practice that doesn't work.
+ poller_fd_reset (&plugin->read_event);
+
+ xclose (plugin->read_fd);
+ plugin->read_fd = -1;
+
+ LIST_UNLINK (ctx->plugins, plugin);
+ plugin_destroy (plugin);
+
+ // Living child processes block us from quitting
+ try_finish_quit (ctx);
+}
+
+static bool
+try_reap_plugin (struct bot_context *ctx)
+{
+ int status;
+ pid_t zombie = waitpid (-1, &status, WNOHANG);
+
+ if (zombie == -1)
+ {
+ // No children to wait on
+ if (errno == ECHILD)
+ return false;
+
+ hard_assert (errno == EINTR);
+ return true;
+ }
+
+ if (zombie == 0)
+ return false;
+
+ struct plugin *plugin = plugin_find_by_pid (ctx, zombie);
+ // XXX: re-exec if something has died that we don't recognize?
+ if (soft_assert (plugin != NULL))
+ on_plugin_death (plugin, status);
+ return true;
+}
+
+static void
+kill_all_zombies (struct bot_context *ctx)
+{
+ for (struct plugin *plugin = ctx->plugins; plugin; plugin = plugin->next)
+ {
+ if (!plugin->is_zombie)
+ continue;
+
+ print_status ("forcefully killing a zombie of `%s' (PID %d)",
+ plugin->name, (int) plugin->pid);
+ kill (plugin->pid, SIGKILL);
+ }
+}
+
+static void
+on_signal_pipe_readable (const struct pollfd *fd, struct bot_context *ctx)
+{
+ char dummy;
+ (void) read (fd->fd, &dummy, 1);
+
+ if (g_termination_requested)
+ {
+ g_termination_requested = false;
+ if (!ctx->quitting)
+ {
+ // There may be a timer set to reconnect to the server
+ irc_cancel_timers (ctx);
+
+ if (ctx->irc_fd != -1)
+ irc_send (ctx, "QUIT :Terminated by signal");
+ initiate_quit (ctx);
+ }
+ else
+ // Disregard proper termination, just kill all the children
+ kill_all_zombies (ctx);
+ }
+
+ // Reap all dead children (since the signal pipe may overflow etc. we run
+ // waitpid() in a loop to return all the zombies it knows about).
+ while (try_reap_plugin (ctx))
+ ;
+}
+
+int
+main (int argc, char *argv[])
+{
+ g_original_argv = strv_make ();
+ strv_append_vector (&g_original_argv, argv);
+
+ static const struct opt opts[] =
+ {
+ { 'd', "debug", NULL, 0, "run in debug mode" },
+ { 'h', "help", NULL, 0, "display this help and exit" },
+ { 'V', "version", NULL, 0, "output version information and exit" },
+ { 'w', "write-default-cfg", "FILENAME",
+ OPT_OPTIONAL_ARG | OPT_LONG_ONLY,
+ "write a default configuration file and exit" },
+ { 0, NULL, NULL, 0, NULL }
+ };
+
+ struct opt_handler oh =
+ opt_handler_make (argc, argv, opts, NULL, "Modular IRC bot.");
+
+ int c;
+ while ((c = opt_handler_get (&oh)) != -1)
+ switch (c)
+ {
+ case 'd':
+ g_debug_mode = true;
+ break;
+ case 'h':
+ opt_handler_usage (&oh, stdout);
+ exit (EXIT_SUCCESS);
+ case 'V':
+ printf (PROGRAM_NAME " " PROGRAM_VERSION "\n");
+ exit (EXIT_SUCCESS);
+ case 'w':
+ call_simple_config_write_default (optarg, g_config_table);
+ exit (EXIT_SUCCESS);
+ default:
+ print_error ("wrong options");
+ opt_handler_usage (&oh, stderr);
+ exit (EXIT_FAILURE);
+ }
+
+ opt_handler_free (&oh);
+
+ print_status (PROGRAM_NAME " " PROGRAM_VERSION " starting");
+ setup_signal_handlers ();
+ init_openssl ();
+
+ struct bot_context ctx;
+ bot_context_init (&ctx);
+
+ struct error *e = NULL;
+ if (!simple_config_update_from_file (&ctx.config, &e)
+ || !setup_recovery_handler (&ctx, &e))
+ {
+ print_error ("%s", e->message);
+ error_free (e);
+ exit (EXIT_FAILURE);
+ }
+
+ ctx.signal_event = poller_fd_make (&ctx.poller, g_signal_pipe[0]);
+ ctx.signal_event.dispatcher = (poller_fd_fn) on_signal_pipe_readable;
+ ctx.signal_event.user_data = &ctx;
+ poller_fd_set (&ctx.signal_event, POLLIN);
+
+#if OpenBSD >= 201605
+ // cpath is for creating the plugin home directory
+ if (pledge ("stdio rpath cpath inet proc exec", NULL))
+ exit_fatal ("%s: %s", "pledge", strerror (errno));
+#endif
+
+ plugin_load_all_from_config (&ctx);
+ if (!parse_config (&ctx, &e)
+ || !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);
+ strv_free (&g_original_argv);
+ return EXIT_SUCCESS;
+}
+