/* * common.c: common functionality * * 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 #include #include #include #include #ifndef NI_MAXHOST #define NI_MAXHOST 1025 #endif // ! NI_MAXHOST #ifndef NI_MAXSERV #define NI_MAXSERV 32 #endif // ! NI_MAXSERV #include #include #include #include "siphash.h" extern char **environ; #ifdef _POSIX_MONOTONIC_CLOCK #define CLOCK_BEST CLOCK_MONOTONIC #else // ! _POSIX_MONOTIC_CLOCK #define CLOCK_BEST CLOCK_REALTIME #endif // ! _POSIX_MONOTONIC_CLOCK #if defined __GNUC__ #define ATTRIBUTE_PRINTF(x, y) __attribute__ ((format (printf, x, y))) #else // ! __GNUC__ #define ATTRIBUTE_PRINTF(x, y) #endif // ! __GNUC__ #if defined __GNUC__ && __GNUC__ >= 4 #define ATTRIBUTE_SENTINEL __attribute__ ((sentinel)) #else // ! __GNUC__ || __GNUC__ < 4 #define ATTRIBUTE_SENTINEL #endif // ! __GNUC__ || __GNUC__ < 4 #define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0])) #define BLOCK_START do { #define BLOCK_END } while (0) // --- 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 }; // As long as you don't remove the current entry, you can modify the map. // Use `link' directly to access the data. struct str_map_iter { struct str_map *map; ///< The map we're iterating size_t next_index; ///< Next table index to search struct str_map_link *link; ///< Current link }; #define STR_MAP_MIN_ALLOC 16 typedef void (*str_map_free_func) (void *); static void str_map_init (struct str_map *self) { self->alloc = STR_MAP_MIN_ALLOC; self->len = 0; self->free = NULL; self->map = xcalloc (self->alloc, sizeof *self->map); } static void str_map_free (struct str_map *self) { struct str_map_link **iter, **end = self->map + self->alloc; struct str_map_link *link, *tmp; for (iter = self->map; iter < end; iter++) for (link = *iter; link; link = tmp) { tmp = link->next; if (self->free) self->free (link->data); free (link); } free (self->map); self->map = NULL; } static void str_map_iter_init (struct str_map_iter *self, struct str_map *map) { self->map = map; self->next_index = 0; self->link = NULL; } static bool str_map_iter_next (struct str_map_iter *self) { struct str_map *map = self->map; if (self->link) self->link = self->link->next; while (!self->link) { if (self->next_index >= map->len) return false; self->link = map->map[self->next_index++]; } return true; } 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 *); typedef void (*poller_timer_func) (void *); #define POLLER_MIN_ALLOC 16 struct poller_timer_info { int64_t when; ///< When is the timer to expire poller_timer_func dispatcher; ///< Event dispatcher void *user_data; ///< User data }; struct poller_timers { struct poller_timer_info *info; ///< Min-heap of timers size_t len; ///< Number of scheduled timers size_t alloc; ///< Number of timers allocated }; static void poller_timers_init (struct poller_timers *self) { self->alloc = POLLER_MIN_ALLOC; self->len = 0; self->info = xmalloc (self->alloc * sizeof *self->info); } static void poller_timers_free (struct poller_timers *self) { free (self->info); } static int64_t poller_timers_get_current_time (void) { #ifdef _POSIX_TIMERS struct timespec tp; hard_assert (clock_gettime (CLOCK_BEST, &tp) != -1); return (int64_t) tp.tv_sec * 1000 + (int64_t) tp.tv_nsec / 1000000; #else struct timeval tp; gettimeofday (&tp, NULL); return (int64_t) tp.tv_sec * 1000 + (int64_t) tp.tv_usec / 1000; #endif } static void poller_timers_heapify_down (struct poller_timers *self, size_t index) { typedef struct poller_timer_info info_t; info_t *end = self->info + self->len; while (true) { info_t *parent = self->info + index; info_t *left = self->info + 2 * index + 1; info_t *right = self->info + 2 * index + 2; info_t *largest = parent; if (left < end && left->when > largest->when) largest = left; if (right < end && right->when > largest->when) largest = right; if (parent == largest) break; info_t tmp = *parent; *parent = *largest; *largest = tmp; index = largest - self->info; } } static void poller_timers_remove_at_index (struct poller_timers *self, size_t index) { hard_assert (index < self->len); if (index == --self->len) return; self->info[index] = self->info[self->len]; poller_timers_heapify_down (self, index); } static void poller_timers_dispatch (struct poller_timers *self) { int64_t now = poller_timers_get_current_time (); while (self->len && self->info->when <= now) { struct poller_timer_info info = *self->info; poller_timers_remove_at_index (self, 0); info.dispatcher (info.user_data); } } static void poller_timers_heapify_up (struct poller_timers *self, size_t index) { while (index != 0) { size_t parent = (index - 1) / 2; if (self->info[parent].when <= self->info[index].when) break; struct poller_timer_info tmp = self->info[parent]; self->info[parent] = self->info[index]; self->info[index] = tmp; index = parent; } } static ssize_t poller_timers_find (struct poller_timers *self, poller_timer_func dispatcher, void *data) { // NOTE: there may be duplicates. for (size_t i = 0; i < self->len; i++) if (self->info[i].dispatcher == dispatcher && self->info[i].user_data == data) return i; return -1; } static void poller_timers_add (struct poller_timers *self, poller_timer_func dispatcher, void *data, int timeout_ms) { if (self->len == self->alloc) self->info = xreallocarray (self->info, self->alloc <<= 1, sizeof *self->info); self->info[self->len] = (struct poller_timer_info) { .when = poller_timers_get_current_time () + timeout_ms, .dispatcher = dispatcher, .user_data = data }; poller_timers_heapify_up (self, self->len++); } static int poller_timers_get_poll_timeout (struct poller_timers *self) { if (!self->len) return -1; int64_t timeout = self->info->when - poller_timers_get_current_time (); return timeout >= 0 ? timeout : 0; } #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 struct poller_timers timers; ///< Timeouts /// Index of the element in `revents' that's about to be dispatched next. int dispatch_next; /// The total number of entries stored in `revents' by epoll_wait(). int dispatch_total; }; static void poller_init (struct poller *self) { self->epoll_fd = epoll_create (POLLER_MIN_ALLOC); hard_assert (self->epoll_fd != -1); set_cloexec (self->epoll_fd); self->len = 0; self->alloc = POLLER_MIN_ALLOC; self->info = xcalloc (self->alloc, sizeof *self->info); self->revents = xcalloc (self->alloc, sizeof *self->revents); poller_timers_init (&self->timers); self->dispatch_next = 0; self->dispatch_total = 0; } static void poller_free (struct poller *self) { for (size_t i = 0; i < self->len; i++) { struct poller_info *info = self->info[i]; hard_assert (epoll_ctl (self->epoll_fd, EPOLL_CTL_DEL, info->fd, (void *) "") != -1); free (info); } poller_timers_free (&self->timers); xclose (self->epoll_fd); free (self->info); free (self->revents); } static ssize_t poller_find_by_fd (struct poller *self, int fd) { for (size_t i = 0; i < self->len; i++) if (self->info[i]->fd == fd) return i; return -1; } static void poller_ensure_space (struct poller *self) { if (self->len < self->alloc) return; self->alloc <<= 1; 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_total) return; int i; for (i = self->dispatch_next; i < self->dispatch_total; i++) if (self->revents[i].data.ptr == info) break; if (i == self->dispatch_total) return; if (i != --self->dispatch_total) self->revents[i] = self->revents[self->dispatch_total]; } static void poller_remove_at_index (struct poller *self, size_t index) { hard_assert (index < self->len); struct poller_info *info = self->info[index]; poller_remove_from_dispatch (self, info); hard_assert (epoll_ctl (self->epoll_fd, EPOLL_CTL_DEL, info->fd, (void *) "") != -1); free (info); if (index != --self->len) self->info[index] = self->info[self->len]; } static void poller_run (struct poller *self) { // Not reentrant hard_assert (!self->dispatch_total); int n_fds; do n_fds = epoll_wait (self->epoll_fd, self->revents, self->len, poller_timers_get_poll_timeout (&self->timers)); while (n_fds == -1 && errno == EINTR); if (n_fds == -1) { print_fatal ("%s: %s", "epoll", strerror (errno)); exit (EXIT_FAILURE); } poller_timers_dispatch (&self->timers); self->dispatch_next = 0; self->dispatch_total = n_fds; while (self->dispatch_next < self->dispatch_total) { struct epoll_event *revents = self->revents + self->dispatch_next; struct poller_info *info = revents->data.ptr; struct pollfd pfd; pfd.fd = info->fd; pfd.revents = poller_epoll_to_poll_events (revents->events); pfd.events = poller_epoll_to_poll_events (info->events); self->dispatch_next++; info->dispatcher (&pfd, info->user_data); } self->dispatch_next = 0; self->dispatch_total = 0; } #else // !__linux__ struct poller_info { poller_dispatcher_func dispatcher; ///< Event dispatcher void *user_data; ///< User data }; struct poller { struct pollfd *fds; ///< Polled descriptors struct poller_info *fds_info; ///< Additional information for each FD size_t len; ///< Number of polled descriptors size_t alloc; ///< Number of entries allocated struct poller_timers timers; ///< Timers int dispatch_next; ///< The next dispatched FD or -1 }; static void poller_init (struct poller *self) { self->alloc = POLLER_MIN_ALLOC; self->len = 0; self->fds = xcalloc (self->alloc, sizeof *self->fds); self->fds_info = xcalloc (self->alloc, sizeof *self->fds_info); poller_timers_init (&self->timers); self->dispatch_next = -1; } static void poller_free (struct poller *self) { free (self->fds); free (self->fds_info); poller_timers_free (&self->timers); } static ssize_t poller_find_by_fd (struct poller *self, int fd) { for (size_t i = 0; i < self->len; i++) if (self->fds[i].fd == fd) return i; return -1; } static void poller_ensure_space (struct poller *self) { if (self->len < self->alloc) return; self->alloc <<= 1; self->fds = xreallocarray (self->fds, sizeof *self->fds, self->alloc); self->fds_info = xreallocarray (self->fds_info, sizeof *self->fds_info, self->alloc); } static void poller_set (struct poller *self, int fd, short 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_next) { memmove (self->fds + index, self->fds + index + 1, (self->len - index) * sizeof *self->fds); memmove (self->fds_info + index, self->fds_info + index + 1, (self->len - index) * sizeof *self->fds_info); self->dispatch_next--; } else { self->fds[index] = self->fds[self->len]; self->fds_info[index] = self->fds_info[self->len]; } } static void poller_run (struct poller *self) { // Not reentrant hard_assert (self->dispatch_next == -1); int result; do result = poll (self->fds, self->len, poller_timers_get_poll_timeout (&self->timers)); while (result == -1 && errno == EINTR); if (result == -1) { print_fatal ("%s: %s", "poll", strerror (errno)); exit (EXIT_FAILURE); } poller_timers_dispatch (&self->timers); for (int i = 0; i < (int) self->len; ) { struct pollfd pfd = self->fds[i]; if (!pfd.revents) continue; struct poller_info *info = self->fds_info + i; self->dispatch_next = ++i; info->dispatcher (&pfd, info->user_data); i = self->dispatch_next; } self->dispatch_next = -1; } #endif // !__linux__ // --- Utilities --------------------------------------------------------------- static void split_str_ignore_empty (const char *s, char delimiter, struct str_vector *out) { const char *begin = s, *end; while ((end = strchr (begin, delimiter))) { if (begin != end) str_vector_add_owned (out, xstrndup (begin, end - begin)); begin = ++end; } if (*begin) str_vector_add (out, begin); } static char * strip_str_in_place (char *s, const char *stripped_chars) { char *end = s + strlen (s); while (end > s && strchr (stripped_chars, end[-1])) *--end = '\0'; char *start = s + strspn (s, stripped_chars); if (start > s) memmove (s, start, end - start + 1); return s; } static 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 bool xstrtoul (unsigned long *out, const char *s, int base) { char *end; errno = 0; *out = strtoul (s, &end, base); return errno == 0 && !*end && end != s; } static bool read_line (FILE *fp, struct str *s) { int c; bool at_end = true; str_reset (s); while ((c = fgetc (fp)) != EOF) { at_end = false; if (c == '\r') continue; if (c == '\n') break; str_append_c (s, c); } return !at_end; } #define XSSL_ERROR_TRY_AGAIN INT_MAX /// A small wrapper around SSL_get_error() to simplify further handling static int xssl_get_error (SSL *ssl, int result, const char **error_info) { int error = SSL_get_error (ssl, result); switch (error) { case SSL_ERROR_NONE: case SSL_ERROR_ZERO_RETURN: case SSL_ERROR_WANT_READ: case SSL_ERROR_WANT_WRITE: return error; case SSL_ERROR_SYSCALL: if ((error = ERR_get_error ())) *error_info = ERR_error_string (error, NULL); else if (result == 0) // An EOF that's not according to the protocol is still an EOF return SSL_ERROR_ZERO_RETURN; else { if (errno == EINTR) return XSSL_ERROR_TRY_AGAIN; *error_info = strerror (errno); } return SSL_ERROR_SSL; default: if ((error = ERR_get_error ())) *error_info = ERR_error_string (error, NULL); else *error_info = "Unknown error"; return SSL_ERROR_SSL; } } // --- Regular expressions ----------------------------------------------------- static size_t regex_error_domain_tag; #define REGEX_ERROR (error_resolve_domain (®ex_error_domain_tag)) enum { REGEX_ERROR_COMPILATION_FAILED }; static regex_t * regex_compile (const char *regex, int flags, struct error **e) { regex_t *re = xmalloc (sizeof *re); int err = regcomp (re, regex, flags); if (!err) return re; struct str desc; str_init (&desc); size_t required = regerror (err, re, NULL, 0); str_ensure_space (&desc, required); desc.len += regerror (err, re, desc.str + desc.len, desc.alloc - desc.len) - 1; free (re); error_set (e, REGEX_ERROR, REGEX_ERROR_COMPILATION_FAILED, "%s: %s", "failed to compile regular expression", desc.str); str_free (&desc); return NULL; } static void regex_free (void *regex) { regfree (regex); free (regex); } // The cost of hashing a string is likely to be significantly smaller than that // of compiling the whole regular expression anew, so here is a simple cache. // Adding basic support for subgroups is easy: check `re_nsub' and output into // a `struct str_vector' (if all we want is the substrings). static void regex_cache_init (struct str_map *cache) { str_map_init (cache); cache->free = regex_free; } static bool regex_cache_match (struct str_map *cache, const char *regex, int flags, const char *s, struct error **e) { regex_t *re = str_map_find (cache, regex); if (!re) { re = regex_compile (regex, flags, e); if (!re) return false; str_map_set (cache, regex, re); } return regexec (re, s, 0, NULL, 0) != REG_NOMATCH; } // --- IRC utilities ----------------------------------------------------------- struct irc_message { struct str_map tags; ///< IRC 3.2 message tags char *prefix; ///< Message prefix char *command; ///< IRC command struct str_vector params; ///< Command parameters }; static void irc_parse_message_tags (const char *tags, struct str_map *out) { struct str_vector v; str_vector_init (&v); split_str_ignore_empty (tags, ';', &v); for (size_t i = 0; i < v.len; i++) { char *key = v.vector[i], *equal_sign = strchr (key, '='); if (equal_sign) { *equal_sign = '\0'; str_map_set (out, key, xstrdup (equal_sign + 1)); } else str_map_set (out, key, xstrdup ("")); } str_vector_free (&v); } static void irc_parse_message (struct irc_message *msg, const char *line) { str_map_init (&msg->tags); msg->tags.free = free; msg->prefix = NULL; msg->command = NULL; str_vector_init (&msg->params); // IRC 3.2 message tags if (*line == '@') { size_t tags_len = strcspn (++line, " "); char *tags = xstrndup (line, tags_len); irc_parse_message_tags (tags, &msg->tags); free (tags); line += tags_len; while (*line == ' ') line++; } // Prefix if (*line == ':') { size_t prefix_len = strcspn (++line, " "); msg->prefix = xstrndup (line, prefix_len); line += prefix_len; } // Command name { while (*line == ' ') line++; size_t cmd_len = strcspn (line, " "); msg->command = xstrndup (line, cmd_len); line += cmd_len; } // Arguments while (true) { while (*line == ' ') line++; if (*line == ':') { str_vector_add (&msg->params, ++line); break; } size_t param_len = strcspn (line, " "); if (!param_len) break; str_vector_add_owned (&msg->params, xstrndup (line, param_len)); line += param_len; } } static void irc_free_message (struct irc_message *msg) { str_map_free (&msg->tags); free (msg->prefix); free (msg->command); str_vector_free (&msg->params); } static void irc_process_buffer (struct str *buf, void (*callback)(const struct irc_message *, const char *, void *), void *user_data) { char *start = buf->str, *end = start + buf->len; for (char *p = start; p + 1 < end; p++) { // Split the input on newlines if (p[0] != '\r' || p[1] != '\n') continue; *p = 0; struct irc_message msg; irc_parse_message (&msg, start); callback (&msg, start, user_data); irc_free_message (&msg); start = p + 2; } // XXX: we might want to just advance some kind of an offset to avoid // moving memory around unnecessarily. str_remove_slice (buf, 0, start - buf->str); } static int irc_tolower (char c) { if (c == '[') return '{'; if (c == ']') return '}'; if (c == '\\') return '|'; if (c == '~') return '^'; return c >= 'A' && c <= 'Z' ? c + ('a' - 'A') : c; } static int irc_strcmp (const char *a, const char *b) { int x; while (*a || *b) if ((x = irc_tolower (*a++) - irc_tolower (*b++))) return x; return 0; } // --- 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 void load_config_defaults (struct str_map *config, const struct config_item *table) { for (; table->key != NULL; table++) if (table->default_value) str_map_set (config, table->key, xstrdup (table->default_value)); else str_map_set (config, table->key, NULL); } static bool read_config_file (struct str_map *config, struct error **e) { 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; } static char * write_default_config (const char *filename, const struct config_item *table, struct error **e) { struct str path, base; str_init (&path); str_init (&base); if (filename) { char *tmp = xstrdup (filename); str_append (&path, dirname (tmp)); strcpy (tmp, filename); str_append (&base, basename (tmp)); free (tmp); } else { get_xdg_home_dir (&path, "XDG_CONFIG_HOME", ".config"); str_append (&path, "/" PROGRAM_NAME); str_append (&base, PROGRAM_NAME ".conf"); } if (!mkdir_with_parents (path.str, e)) goto error; str_append_c (&path, '/'); str_append_str (&path, &base); FILE *fp = fopen (path.str, "w"); if (!fp) { error_set (e, IO_ERROR, IO_ERROR_FAILED, "could not open `%s' for writing: %s", path.str, strerror (errno)); goto error; } errno = 0; for (; table->key != NULL; table++) { fprintf (fp, "# %s\n", table->description); if (table->default_value) fprintf (fp, "%s=%s\n", table->key, table->default_value); else fprintf (fp, "#%s=\n", table->key); } fclose (fp); if (errno) { error_set (e, IO_ERROR, IO_ERROR_FAILED, "writing to `%s' failed: %s", path.str, strerror (errno)); goto error; } str_free (&base); return str_steal (&path); error: str_free (&base); str_free (&path); return NULL; }