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