/* * utils.c: utilities * * Copyright (c) 2014, Přemysl 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 PROGRAM_NAME "ponymap" #define PROGRAM_VERSION "alpha" #define _POSIX_C_SOURCE 199309L #define _XOPEN_SOURCE 600 #include #include #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) #define MIN(a, b) ((a) < (b) ? (a) : (b)) #define MAX(a, b) ((a) > (b) ? (a) : (b)) #define STRINGIFY(x) #x #define XSTRINGIFY(x) STRINGIFY (x) // --- Logging ----------------------------------------------------------------- static void log_message_syslog (int prio, const char *quote, const char *fmt, va_list ap) { va_list va; va_copy (va, ap); int size = vsnprintf (NULL, 0, fmt, va); va_end (va); if (size < 0) return; char buf[size + 1]; if (vsnprintf (buf, sizeof buf, fmt, ap) >= 0) syslog (prio, "%s%s", quote, buf); } static void log_message_stdio (int prio, const char *quote, const char *fmt, va_list ap) { (void) prio; FILE *stream = stderr; fputs (quote, stream); vfprintf (stream, fmt, ap); fputs ("\n", stream); } static void (*g_log_message_real) (int, const char *, const char *, va_list) = log_message_stdio; static void log_message (int priority, const char *quote, const char *fmt, ...) ATTRIBUTE_PRINTF (3, 4); static void log_message (int priority, const char *quote, const char *fmt, ...) { va_list ap; va_start (ap, fmt); g_log_message_real (priority, quote, fmt, ap); va_end (ap); } // `fatal' is reserved for unexpected failures that would harm further operation #define print_fatal(...) log_message (LOG_ERR, "fatal: ", __VA_ARGS__) #define print_error(...) log_message (LOG_ERR, "error: ", __VA_ARGS__) #define print_warning(...) log_message (LOG_WARNING, "warning: ", __VA_ARGS__) #define print_status(...) log_message (LOG_INFO, "-- ", __VA_ARGS__) #define exit_fatal(...) \ BLOCK_START \ print_fatal (__VA_ARGS__); \ exit (EXIT_FAILURE); \ BLOCK_END // --- Debugging and assertions ------------------------------------------------ // We should check everything that may possibly fail with at least a soft // assertion, so that any causes for problems don't slip us by silently. // // `g_soft_asserts_are_deadly' may be useful while running inside a debugger. static bool g_debug_mode; ///< Debug messages are printed static bool g_soft_asserts_are_deadly; ///< soft_assert() aborts as well #define print_debug(...) \ BLOCK_START \ if (g_debug_mode) \ log_message (LOG_DEBUG, "debug: ", __VA_ARGS__); \ BLOCK_END static void assertion_failure_handler (bool is_fatal, const char *file, int line, const char *function, const char *condition) { if (is_fatal) { print_fatal ("assertion failed [%s:%d in function %s]: %s", file, line, function, condition); abort (); } else print_debug ("assertion failed [%s:%d in function %s]: %s", file, line, function, condition); } #define soft_assert(condition) \ ((condition) ? true : \ (assertion_failure_handler (g_soft_asserts_are_deadly, \ __FILE__, __LINE__, __func__, #condition), false)) #define hard_assert(condition) \ ((condition) ? (void) 0 : \ assertion_failure_handler (true, \ __FILE__, __LINE__, __func__, #condition)) // --- Safe memory management -------------------------------------------------- // When a memory allocation fails and we need the memory, we're usually pretty // much fucked. Use the non-prefixed versions when there's a legitimate // worry that an unrealistic amount of memory may be requested for allocation. // XXX: it's not a good idea to use print_message() as it may want to allocate // further memory for printf() and the output streams. That may fail. static void * xmalloc (size_t n) { void *p = malloc (n); if (!p) exit_fatal ("malloc: %s", strerror (errno)); return p; } static void * xcalloc (size_t n, size_t m) { void *p = calloc (n, m); if (!p && n && m) exit_fatal ("calloc: %s", strerror (errno)); return p; } static void * xrealloc (void *o, size_t n) { void *p = realloc (o, n); if (!p && n) exit_fatal ("realloc: %s", strerror (errno)); return p; } static void * xreallocarray (void *o, size_t n, size_t m) { if (m && n > SIZE_MAX / m) { errno = ENOMEM; exit_fatal ("reallocarray: %s", strerror (errno)); } return xrealloc (o, n * m); } static char * xstrdup (const char *s) { return strcpy (xmalloc (strlen (s) + 1), s); } static char * xstrndup (const char *s, size_t n) { size_t size = strlen (s); if (n > size) n = size; char *copy = xmalloc (n + 1); memcpy (copy, s, n); copy[n] = '\0'; return copy; } // --- Double-linked list helpers ---------------------------------------------- #define LIST_HEADER(type) \ struct type *next; \ struct type *prev; #define LIST_PREPEND(head, link) \ BLOCK_START \ (link)->prev = NULL; \ (link)->next = (head); \ if ((link)->next) \ (link)->next->prev = (link); \ (head) = (link); \ BLOCK_END #define LIST_UNLINK(head, link) \ BLOCK_START \ if ((link)->prev) \ (link)->prev->next = (link)->next; \ else \ (head) = (link)->next; \ if ((link)->next) \ (link)->next->prev = (link)->prev; \ BLOCK_END #define LIST_APPEND_WITH_TAIL(head, tail, link) \ BLOCK_START \ (link)->prev = (tail); \ (link)->next = NULL; \ if ((link)->prev) \ (link)->prev->next = (link); \ else \ (head) = (link); \ (tail) = (link); \ BLOCK_END #define LIST_UNLINK_WITH_TAIL(head, tail, link) \ BLOCK_START \ if ((tail) == (link)) \ (tail) = (link)->prev; \ LIST_UNLINK ((head), (link)); \ BLOCK_END // --- Dynamically allocated string array -------------------------------------- struct str_vector { char **vector; size_t len; size_t alloc; }; static void str_vector_init (struct str_vector *self) { self->alloc = 4; self->len = 0; self->vector = xcalloc (sizeof *self->vector, self->alloc); } static void str_vector_free (struct str_vector *self) { unsigned i; for (i = 0; i < self->len; i++) free (self->vector[i]); free (self->vector); self->vector = NULL; } static void str_vector_reset (struct str_vector *self) { str_vector_free (self); str_vector_init (self); } static void str_vector_add_owned (struct str_vector *self, char *s) { self->vector[self->len] = s; if (++self->len >= self->alloc) self->vector = xreallocarray (self->vector, sizeof *self->vector, (self->alloc <<= 1)); self->vector[self->len] = NULL; } static void str_vector_add (struct str_vector *self, const char *s) { str_vector_add_owned (self, xstrdup (s)); } static void str_vector_add_args (struct str_vector *self, const char *s, ...) ATTRIBUTE_SENTINEL; static void str_vector_add_args (struct str_vector *self, const char *s, ...) { va_list ap; va_start (ap, s); while (s) { str_vector_add (self, s); s = va_arg (ap, const char *); } va_end (ap); } static void str_vector_add_vector (struct str_vector *self, char **vector) { while (*vector) str_vector_add (self, *vector++); } static void str_vector_remove (struct str_vector *self, size_t i) { hard_assert (i < self->len); free (self->vector[i]); memmove (self->vector + i, self->vector + i + 1, (self->len-- - i) * sizeof *self->vector); } // --- Dynamically allocated strings ------------------------------------------- // Basically a string builder to abstract away manual memory management. struct str { char *str; ///< String data, null terminated size_t alloc; ///< How many bytes are allocated size_t len; ///< How long the string actually is }; /// We don't care about allocations that are way too large for the content, as /// long as the allocation is below the given threshold. (Trivial heuristics.) #define STR_SHRINK_THRESHOLD (1 << 20) static void str_init (struct str *self) { self->alloc = 16; self->len = 0; self->str = strcpy (xmalloc (self->alloc), ""); } static void str_free (struct str *self) { free (self->str); self->str = NULL; self->alloc = 0; self->len = 0; } static void str_reset (struct str *self) { str_free (self); str_init (self); } static char * str_steal (struct str *self) { char *str = self->str; self->str = NULL; str_free (self); return str; } static void str_ensure_space (struct str *self, size_t n) { // We allocate at least one more byte for the terminating null character size_t new_alloc = self->alloc; while (new_alloc <= self->len + n) new_alloc <<= 1; if (new_alloc != self->alloc) self->str = xrealloc (self->str, (self->alloc = new_alloc)); } static void str_append_data (struct str *self, const void *data, size_t n) { str_ensure_space (self, n); memcpy (self->str + self->len, data, n); self->len += n; self->str[self->len] = '\0'; } static void str_append_c (struct str *self, char c) { str_append_data (self, &c, 1); } static void str_append (struct str *self, const char *s) { str_append_data (self, s, strlen (s)); } static void str_append_str (struct str *self, const struct str *another) { str_append_data (self, another->str, another->len); } static int str_append_vprintf (struct str *self, const char *fmt, va_list va) { va_list ap; int size; va_copy (ap, va); size = vsnprintf (NULL, 0, fmt, ap); va_end (ap); if (size < 0) return -1; va_copy (ap, va); str_ensure_space (self, size); size = vsnprintf (self->str + self->len, self->alloc - self->len, fmt, ap); va_end (ap); if (size > 0) self->len += size; return size; } static int str_append_printf (struct str *self, const char *fmt, ...) ATTRIBUTE_PRINTF (2, 3); static int str_append_printf (struct str *self, const char *fmt, ...) { va_list ap; va_start (ap, fmt); int size = str_append_vprintf (self, fmt, ap); va_end (ap); return size; } static void str_remove_slice (struct str *self, size_t start, size_t length) { size_t end = start + length; hard_assert (end <= self->len); memmove (self->str + start, self->str + end, self->len - end); self->str[self->len -= length] = '\0'; // Shrink the string if the allocation becomes way too large if (self->alloc >= STR_SHRINK_THRESHOLD && self->len < (self->alloc >> 2)) self->str = xrealloc (self->str, self->alloc >>= 2); } // --- Errors ------------------------------------------------------------------ // Error reporting utilities. Inspired by GError, only much simpler. struct error { char *message; ///< Textual description of the event }; static void error_set (struct error **e, const char *message, ...) ATTRIBUTE_PRINTF (2, 3); static void error_set (struct error **e, const char *message, ...) { if (!e) return; va_list ap; va_start (ap, message); int size = vsnprintf (NULL, 0, message, ap); va_end (ap); hard_assert (size >= 0); struct error *tmp = xmalloc (sizeof *tmp); tmp->message = xmalloc (size + 1); va_start (ap, message); size = vsnprintf (tmp->message, size + 1, message, ap); va_end (ap); hard_assert (size >= 0); soft_assert (*e == NULL); *e = tmp; } static void error_free (struct error *e) { free (e->message); free (e); } static void error_propagate (struct error **destination, struct error *source) { if (!destination) { error_free (source); return; } soft_assert (*destination == NULL); *destination = source; } // --- String hash map --------------------------------------------------------- // The most basic map (or associative array). struct str_map_link { LIST_HEADER (str_map_link) void *data; ///< Payload size_t key_length; ///< Length of the key without '\0' char key[]; ///< The key for this link }; struct str_map { struct str_map_link **map; ///< The hash table data itself size_t alloc; ///< Number of allocated entries size_t len; ///< Number of entries in the table void (*free) (void *); ///< Callback to destruct the payload /// Callback that transforms all key values for storage and comparison; /// has to behave exactly like strxfrm(). size_t (*key_xfrm) (char *dest, const char *src, size_t n); }; // As long as you don't remove the current entry, you can modify the map. // Use `link' directly to access the data. struct str_map_iter { struct str_map *map; ///< The map we're iterating size_t next_index; ///< Next table index to search struct str_map_link *link; ///< Current link }; #define STR_MAP_MIN_ALLOC 16 typedef void (*str_map_free_fn) (void *); static void str_map_init (struct str_map *self) { self->alloc = STR_MAP_MIN_ALLOC; self->len = 0; self->free = NULL; self->key_xfrm = NULL; self->map = xcalloc (self->alloc, sizeof *self->map); } static void str_map_free (struct str_map *self) { struct str_map_link **iter, **end = self->map + self->alloc; struct str_map_link *link, *tmp; for (iter = self->map; iter < end; iter++) for (link = *iter; link; link = tmp) { tmp = link->next; if (self->free) self->free (link->data); free (link); } free (self->map); self->map = NULL; } static void str_map_iter_init (struct str_map_iter *self, struct str_map *map) { self->map = map; self->next_index = 0; self->link = NULL; } static void * str_map_iter_next (struct str_map_iter *self) { struct str_map *map = self->map; if (self->link) self->link = self->link->next; while (!self->link) { if (self->next_index >= map->alloc) return NULL; self->link = map->map[self->next_index++]; } return self->link->data; } static uint64_t str_map_hash (const char *s, size_t len) { static unsigned char key[16] = "SipHash 2-4 key!"; return siphash (key, (const void *) s, len); } static uint64_t str_map_pos (struct str_map *self, const char *s) { size_t mask = self->alloc - 1; return str_map_hash (s, strlen (s)) & mask; } static uint64_t str_map_link_hash (struct str_map_link *self) { return str_map_hash (self->key, self->key_length); } static void str_map_resize (struct str_map *self, size_t new_size) { struct str_map_link **old_map = self->map; size_t i, old_size = self->alloc; // Only powers of two, so that we don't need to compute the modulo hard_assert ((new_size & (new_size - 1)) == 0); size_t mask = new_size - 1; self->alloc = new_size; self->map = xcalloc (self->alloc, sizeof *self->map); for (i = 0; i < old_size; i++) { struct str_map_link *iter = old_map[i], *next_iter; while (iter) { next_iter = iter->next; uint64_t pos = str_map_link_hash (iter) & mask; LIST_PREPEND (self->map[pos], iter); iter = next_iter; } } free (old_map); } static void str_map_set_real (struct str_map *self, const char *key, void *value) { uint64_t pos = str_map_pos (self, key); struct str_map_link *iter = self->map[pos]; for (; iter; iter = iter->next) { if (strcmp (key, iter->key)) continue; // Storing the same data doesn't destroy it if (self->free && value != iter->data) self->free (iter->data); if (value) { iter->data = value; return; } LIST_UNLINK (self->map[pos], iter); free (iter); self->len--; // The array should be at least 1/4 full if (self->alloc >= (STR_MAP_MIN_ALLOC << 2) && self->len < (self->alloc >> 2)) str_map_resize (self, self->alloc >> 2); return; } if (!value) return; if (self->len >= self->alloc) { str_map_resize (self, self->alloc << 1); pos = str_map_pos (self, key); } // Link in a new element for the given pair size_t key_length = strlen (key); struct str_map_link *link = xmalloc (sizeof *link + key_length + 1); link->data = value; link->key_length = key_length; memcpy (link->key, key, key_length + 1); LIST_PREPEND (self->map[pos], link); self->len++; } static void str_map_set (struct str_map *self, const char *key, void *value) { if (!self->key_xfrm) { str_map_set_real (self, key, value); return; } char tmp[self->key_xfrm (NULL, key, 0) + 1]; self->key_xfrm (tmp, key, sizeof tmp); str_map_set_real (self, tmp, value); } static void * str_map_find_real (struct str_map *self, const char *key) { struct str_map_link *iter = self->map[str_map_pos (self, key)]; for (; iter; iter = iter->next) if (!strcmp (key, (const char *) iter + sizeof *iter)) return iter->data; return NULL; } static void * str_map_find (struct str_map *self, const char *key) { if (!self->key_xfrm) return str_map_find_real (self, key); char tmp[self->key_xfrm (NULL, key, 0) + 1]; self->key_xfrm (tmp, key, sizeof tmp); return str_map_find_real (self, tmp); } // --- File descriptor utilities ----------------------------------------------- static void set_cloexec (int fd) { soft_assert (fcntl (fd, F_SETFD, fcntl (fd, F_GETFD) | FD_CLOEXEC) != -1); } static bool set_blocking (int fd, bool blocking) { int flags = fcntl (fd, F_GETFL); hard_assert (flags != -1); bool prev = !(flags & O_NONBLOCK); if (blocking) flags &= ~O_NONBLOCK; else flags |= O_NONBLOCK; hard_assert (fcntl (fd, F_SETFL, flags) != -1); return prev; } static void xclose (int fd) { while (close (fd) == -1) if (!soft_assert (errno == EINTR)) break; } // --- Event loop -------------------------------------------------------------- // 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. // Actually it mustn't be totally shitty as scanning exercises it quite a bit. // We sacrifice some memory to allow for O(1) and O(log n) operations. typedef void (*poller_fd_fn) (const struct pollfd *, void *); typedef void (*poller_timer_fn) (void *); typedef void (*poller_idle_fn) (void *); #define POLLER_MIN_ALLOC 16 struct poller_timer { struct poller_timers *timers; ///< The timers part of our poller ssize_t index; ///< Where we are in the array, or -1 int64_t when; ///< When is the timer to expire poller_timer_fn dispatcher; ///< Event dispatcher void *user_data; ///< User data }; struct poller_fd { struct poller *poller; ///< Our poller ssize_t index; ///< Where we are in the array, or -1 int fd; ///< Our file descriptor short events; ///< The poll() events we registered for bool closed; ///< Whether fd has been closed already poller_fd_fn dispatcher; ///< Event dispatcher void *user_data; ///< User data }; struct poller_idle { LIST_HEADER (poller_idle) struct poller *poller; ///< Our poller bool active; ///< Whether we're on the list poller_idle_fn dispatcher; ///< Event dispatcher void *user_data; ///< User data }; // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - struct poller_timers { struct poller_timer **heap; ///< 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->heap = xmalloc (self->alloc * sizeof *self->heap); } static void poller_timers_free (struct poller_timers *self) { free (self->heap); } 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 *timer_t; timer_t *end = self->heap + self->len; while (true) { timer_t *parent = self->heap + index; timer_t *left = self->heap + 2 * index + 1; timer_t *right = self->heap + 2 * index + 2; timer_t *lowest = parent; if (left < end && (*left) ->when < (*lowest)->when) lowest = left; if (right < end && (*right)->when < (*lowest)->when) lowest = right; if (parent == lowest) break; timer_t tmp = *parent; *parent = *lowest; *lowest = tmp; (*parent)->index = parent - self->heap; (*lowest)->index = lowest - self->heap; index = lowest - self->heap; } } static void poller_timers_remove_at_index (struct poller_timers *self, size_t index) { hard_assert (index < self->len); self->heap[index]->index = -1; if (index == --self->len) return; self->heap[index] = self->heap[self->len]; self->heap[index]->index = index; 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->heap[0]->when <= now) { struct poller_timer *timer = self->heap[0]; poller_timers_remove_at_index (self, 0); timer->dispatcher (timer->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->heap[parent]->when <= self->heap[index]->when) break; struct poller_timer *tmp = self->heap[parent]; self->heap[parent] = self->heap[index]; self->heap[index] = tmp; self->heap[parent]->index = parent; self->heap[index] ->index = index; index = parent; } } static void poller_timers_set (struct poller_timers *self, struct poller_timer *timer) { hard_assert (timer->timers == self); if (timer->index != -1) { poller_timers_heapify_down (self, timer->index); poller_timers_heapify_up (self, timer->index); return; } if (self->len == self->alloc) self->heap = xreallocarray (self->heap, self->alloc <<= 1, sizeof *self->heap); self->heap[self->len] = timer; timer->index = self->len; 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->heap[0]->when - poller_timers_get_current_time (); if (timeout <= 0) return 0; if (timeout > INT_MAX) return INT_MAX; return timeout; } // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - static void poller_idle_dispatch (struct poller_idle *list) { struct poller_idle *iter, *next; for (iter = list; iter; iter = next) { next = iter->next; iter->dispatcher (iter->user_data); } } // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - #ifdef __linux__ #include struct poller { int epoll_fd; ///< The epoll FD struct poller_fd **fds; ///< Information associated with each FD int *dummy; ///< For poller_remove_from_dispatch() 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 struct poller_idle *idle; ///< Idle events int revents_len; ///< Number of entries in `revents' }; 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->fds = xcalloc (self->alloc, sizeof *self->fds); self->dummy = xcalloc (self->alloc, sizeof *self->dummy); self->revents = xcalloc (self->alloc, sizeof *self->revents); self->revents_len = 0; poller_timers_init (&self->timers); } static void poller_free (struct poller *self) { for (size_t i = 0; i < self->len; i++) { struct poller_fd *fd = self->fds[i]; hard_assert (epoll_ctl (self->epoll_fd, EPOLL_CTL_DEL, fd->fd, (void *) "") != -1); } poller_timers_free (&self->timers); xclose (self->epoll_fd); free (self->fds); free (self->dummy); free (self->revents); } static void poller_ensure_space (struct poller *self) { if (self->len < self->alloc) return; self->alloc <<= 1; hard_assert (self->alloc != 0); self->revents = xreallocarray (self->revents, sizeof *self->revents, self->alloc); self->fds = xreallocarray (self->fds, sizeof *self->fds, self->alloc); self->dummy = xreallocarray (self->dummy, sizeof *self->dummy, self->alloc); } static short poller_epoll_to_poll_events (uint32_t events) { short result = 0; if (events & EPOLLIN) result |= POLLIN; if (events & EPOLLOUT) result |= POLLOUT; if (events & EPOLLERR) result |= POLLERR; if (events & EPOLLHUP) result |= POLLHUP; if (events & EPOLLPRI) result |= POLLPRI; return result; } static uint32_t poller_poll_to_epoll_events (short events) { uint32_t result = 0; if (events & POLLIN) result |= EPOLLIN; if (events & POLLOUT) result |= EPOLLOUT; if (events & POLLERR) result |= EPOLLERR; if (events & POLLHUP) result |= EPOLLHUP; if (events & POLLPRI) result |= EPOLLPRI; return result; } static void poller_set (struct poller *self, struct poller_fd *fd) { hard_assert (fd->poller == self); bool modifying = true; if (fd->index == -1) { poller_ensure_space (self); self->fds[fd->index = self->len++] = fd; modifying = false; } struct epoll_event event; event.events = poller_poll_to_epoll_events (fd->events); event.data.ptr = fd; hard_assert (epoll_ctl (self->epoll_fd, modifying ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd->fd, &event) != -1); } static int poller_compare_fds (const void *ax, const void *bx) { const struct epoll_event *ay = ax, *by = bx; struct poller_fd *a = ay->data.ptr, *b = by->data.ptr; return a->fd - b->fd; } static void poller_remove_from_dispatch (struct poller *self, const struct poller_fd *fd) { if (!self->revents_len) return; struct epoll_event key = { .data.ptr = (void *) fd }, *fd_event; if ((fd_event = bsearch (&key, self->revents, self->revents_len, sizeof *self->revents, poller_compare_fds))) { fd_event->events = -1; // Don't let any further bsearch()'s touch possibly freed memory int *dummy = self->dummy + (fd_event - self->revents); *dummy = fd->fd; fd_event->data.ptr = (uint8_t *) dummy - offsetof (struct poller_fd, fd); } } static void poller_remove_at_index (struct poller *self, size_t index) { hard_assert (index < self->len); struct poller_fd *fd = self->fds[index]; fd->index = -1; poller_remove_from_dispatch (self, fd); if (!fd->closed) hard_assert (epoll_ctl (self->epoll_fd, EPOLL_CTL_DEL, fd->fd, (void *) "") != -1); if (index != --self->len) { self->fds[index] = self->fds[self->len]; self->fds[index]->index = index; } } static void poller_run (struct poller *self) { // Not reentrant hard_assert (!self->revents_len); int n_fds; do n_fds = epoll_wait (self->epoll_fd, self->revents, self->len, self->idle ? 0 : poller_timers_get_poll_timeout (&self->timers)); while (n_fds == -1 && errno == EINTR); if (n_fds == -1) exit_fatal ("%s: %s", "epoll", strerror (errno)); // Sort them by file descriptor number for binary search qsort (self->revents, n_fds, sizeof *self->revents, poller_compare_fds); self->revents_len = n_fds; poller_timers_dispatch (&self->timers); poller_idle_dispatch (self->idle); for (int i = 0; i < n_fds; i++) { struct epoll_event *revents = self->revents + i; if (revents->events == (uint32_t) -1) continue; struct poller_fd *fd = revents->data.ptr; struct pollfd pfd; pfd.fd = fd->fd; pfd.revents = poller_epoll_to_poll_events (revents->events); pfd.events = fd->events; fd->dispatcher (&pfd, fd->user_data); } self->revents_len = 0; } #else // !__linux__ struct poller { struct pollfd *fds; ///< Polled descriptors struct poller_fd **fds_data; ///< Additional information for each FD size_t len; ///< Number of polled descriptors size_t alloc; ///< Number of entries allocated struct poller_timers timers; ///< Timers struct poller_idle *idle; ///< Idle events 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_data = xcalloc (self->alloc, sizeof *self->fds_data); poller_timers_init (&self->timers); self->dispatch_next = -1; } static void poller_free (struct poller *self) { free (self->fds); free (self->fds_data); poller_timers_free (&self->timers); } 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_data = xreallocarray (self->fds_data, sizeof *self->fds_data, self->alloc); } static void poller_set (struct poller *self, struct poller_fd *fd) { hard_assert (fd->poller == self); if (fd->index == -1) { poller_ensure_space (self); self->fds_data[fd->index = self->len++] = fd; } struct pollfd *new_entry = self->fds + fd->index; memset (new_entry, 0, sizeof *new_entry); new_entry->fd = fd->fd; new_entry->events = fd->events; } static void poller_remove_at_index (struct poller *self, size_t index) { hard_assert (index < self->len); struct poller_fd *fd = self->fds_data[index]; fd->index = -1; 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_data + index, self->fds_data + index + 1, (self->len - index) * sizeof *self->fds_data); for (size_t i = index; i < self->len; i++) self->fds_data[i]->index = i; self->dispatch_next--; } else { self->fds[index] = self->fds [self->len]; self->fds_data[index] = self->fds_data[self->len]; self->fds_data[index]->index = index; } } static void poller_run (struct poller *self) { // Not reentrant hard_assert (self->dispatch_next == -1); int result; do result = poll (self->fds, self->len, self->idle ? 0 : poller_timers_get_poll_timeout (&self->timers)); while (result == -1 && errno == EINTR); if (result == -1) exit_fatal ("%s: %s", "poll", strerror (errno)); poller_timers_dispatch (&self->timers); poller_idle_dispatch (self->idle); for (int i = 0; i < (int) self->len; ) { struct pollfd pfd = self->fds[i]; struct poller_fd *fd = self->fds_data[i]; self->dispatch_next = ++i; if (pfd.revents) fd->dispatcher (&pfd, fd->user_data); i = self->dispatch_next; } self->dispatch_next = -1; } #endif // !__linux__ // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - static void poller_timer_init (struct poller_timer *self, struct poller *poller) { memset (self, 0, sizeof *self); self->timers = &poller->timers; self->index = -1; } static void poller_timer_set (struct poller_timer *self, int timeout_ms) { self->when = poller_timers_get_current_time () + timeout_ms; poller_timers_set (self->timers, self); } static void poller_timer_reset (struct poller_timer *self) { if (self->index != -1) poller_timers_remove_at_index (self->timers, self->index); } // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - static void poller_idle_init (struct poller_idle *self, struct poller *poller) { memset (self, 0, sizeof *self); self->poller = poller; } static void poller_idle_set (struct poller_idle *self) { if (self->active) return; LIST_PREPEND (self->poller->idle, self); self->active = true; } static void poller_idle_reset (struct poller_idle *self) { if (!self->active) return; LIST_UNLINK (self->poller->idle, self); self->prev = NULL; self->next = NULL; self->active = false; } // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - static void poller_fd_init (struct poller_fd *self, struct poller *poller, int fd) { memset (self, 0, sizeof *self); self->poller = poller; self->index = -1; self->fd = fd; } static void poller_fd_set (struct poller_fd *self, short events) { self->events = events; poller_set (self->poller, self); } static void poller_fd_reset (struct poller_fd *self) { if (self->index != -1) poller_remove_at_index (self->poller, self->index); } // --- Utilities --------------------------------------------------------------- static void split_str_ignore_empty (const char *s, char delimiter, struct str_vector *out) { const char *begin = s, *end; while ((end = strchr (begin, delimiter))) { if (begin != end) str_vector_add_owned (out, xstrndup (begin, end - begin)); begin = ++end; } if (*begin) str_vector_add (out, begin); } static char * strip_str_in_place (char *s, const char *stripped_chars) { char *end = s + strlen (s); while (end > s && strchr (stripped_chars, end[-1])) *--end = '\0'; char *start = s + strspn (s, stripped_chars); if (start > s) memmove (s, start, end - start + 1); return s; } static char * join_str_vector (const struct str_vector *v, char delimiter) { if (!v->len) return xstrdup (""); struct str result; str_init (&result); str_append (&result, v->vector[0]); for (size_t i = 1; i < v->len; i++) str_append_printf (&result, "%c%s", delimiter, v->vector[i]); return str_steal (&result); } static char *xstrdup_printf (const char *, ...) ATTRIBUTE_PRINTF (1, 2); static char * xstrdup_printf (const char *format, ...) { va_list ap; struct str tmp; str_init (&tmp); va_start (ap, format); str_append_vprintf (&tmp, format, ap); va_end (ap); return str_steal (&tmp); } static bool str_append_env_path (struct str *output, const char *var, bool only_absolute) { const char *value = getenv (var); if (!value || (only_absolute && *value != '/')) return false; str_append (output, value); return true; } static void get_xdg_home_dir (struct str *output, const char *var, const char *def) { str_reset (output); if (!str_append_env_path (output, var, true)) { str_append_env_path (output, "HOME", false); str_append_c (output, '/'); str_append (output, def); } } static void get_xdg_config_dirs (struct str_vector *out) { struct str config_home; str_init (&config_home); get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config"); str_vector_add (out, config_home.str); str_free (&config_home); const char *xdg_config_dirs; if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS"))) split_str_ignore_empty (xdg_config_dirs, ':', out); } static char * resolve_config_filename (const char *filename) { // Absolute path is absolute if (*filename == '/') return xstrdup (filename); struct str_vector paths; str_vector_init (&paths); get_xdg_config_dirs (&paths); struct str file; str_init (&file); char *result = NULL; for (unsigned i = 0; i < paths.len; i++) { // As per spec, relative paths are ignored if (*paths.vector[i] != '/') continue; str_reset (&file); str_append_printf (&file, "%s/" PROGRAM_NAME "/%s", paths.vector[i], filename); struct stat st; if (!stat (file.str, &st)) { result = str_steal (&file); break; } } str_vector_free (&paths); str_free (&file); return result; } static bool ensure_directory_existence (const char *path, struct error **e) { struct stat st; if (stat (path, &st)) { if (mkdir (path, S_IRWXU | S_IRWXG | S_IRWXO)) { error_set (e, "cannot create directory `%s': %s", path, strerror (errno)); return false; } } else if (!S_ISDIR (st.st_mode)) { error_set (e, "cannot create directory `%s': %s", path, "file exists but is not a directory"); return false; } return true; } static bool mkdir_with_parents (char *path, struct error **e) { char *p = path; // XXX: This is prone to the TOCTTOU problem. The solution would be to // rewrite the function using the {mkdir,fstat}at() functions from // POSIX.1-2008, ideally returning a file descriptor to the open // directory, with the current code as a fallback. Or to use chdir(). while ((p = strchr (p + 1, '/'))) { *p = '\0'; bool success = ensure_directory_existence (path, e); *p = '/'; if (!success) return false; } return ensure_directory_existence (path, e); } static bool set_boolean_if_valid (bool *out, const char *s) { if (!strcasecmp (s, "yes")) *out = true; else if (!strcasecmp (s, "no")) *out = false; else if (!strcasecmp (s, "on")) *out = true; else if (!strcasecmp (s, "off")) *out = false; else if (!strcasecmp (s, "true")) *out = true; else if (!strcasecmp (s, "false")) *out = false; else return false; return true; } static bool xstrtoul (unsigned long *out, const char *s, int base) { char *end; errno = 0; *out = strtoul (s, &end, base); return errno == 0 && !*end && end != s; } static bool read_line (FILE *fp, struct str *s) { int c; bool at_end = true; str_reset (s); while ((c = fgetc (fp)) != EOF) { at_end = false; if (c == '\r') continue; if (c == '\n') break; str_append_c (s, c); } return !at_end; } #define XSSL_ERROR_TRY_AGAIN INT_MAX /// A small wrapper around SSL_get_error() to simplify further handling static int xssl_get_error (SSL *ssl, int result, const char **error_info) { int error = SSL_get_error (ssl, result); switch (error) { case SSL_ERROR_NONE: case SSL_ERROR_ZERO_RETURN: case SSL_ERROR_WANT_READ: case SSL_ERROR_WANT_WRITE: return error; case SSL_ERROR_SYSCALL: if ((error = ERR_get_error ())) *error_info = ERR_error_string (error, NULL); else if (result == 0) // An EOF that's not according to the protocol is still an EOF return SSL_ERROR_ZERO_RETURN; else { if (errno == EINTR) return XSSL_ERROR_TRY_AGAIN; *error_info = strerror (errno); } return SSL_ERROR_SSL; default: if ((error = ERR_get_error ())) *error_info = ERR_error_string (error, NULL); else *error_info = "Unknown error"; return SSL_ERROR_SSL; } } static char * format_host_port_pair (const char *host, const char *port) { // IPv6 addresses mess with the "colon notation"; let's go with RFC 2732 if (strchr (host, ':')) return xstrdup_printf ("[%s]:%s", host, port); return xstrdup_printf ("%s:%s", host, port); } // --- Regular expressions ----------------------------------------------------- static regex_t * regex_compile (const char *regex, int flags, struct error **e) { regex_t *re = xmalloc (sizeof *re); int err = regcomp (re, regex, flags); if (!err) return re; char buf[regerror (err, re, NULL, 0)]; regerror (err, re, buf, sizeof buf); free (re); error_set (e, "%s: %s", "failed to compile regular expression", buf); return NULL; } static void regex_free (void *regex) { regfree (regex); free (regex); } // The cost of hashing a string is likely to be significantly smaller than that // of compiling the whole regular expression anew, so here is a simple cache. // Adding basic support for subgroups is easy: check `re_nsub' and output into // a `struct str_vector' (if all we want is the substrings). static void regex_cache_init (struct str_map *cache) { str_map_init (cache); cache->free = regex_free; } static bool regex_cache_match (struct str_map *cache, const char *regex, int flags, const char *s, struct error **e) { regex_t *re = str_map_find (cache, regex); if (!re) { re = regex_compile (regex, flags, e); if (!re) return false; str_map_set (cache, regex, re); } return regexec (re, s, 0, NULL, 0) != REG_NOMATCH; } // --- Configuration ----------------------------------------------------------- // The keys are stripped of surrounding whitespace, the values are not. struct config_item { const char *key; const char *default_value; const char *description; }; static void load_config_defaults (struct str_map *config, const struct config_item *table) { for (; table->key != NULL; table++) if (table->default_value) str_map_set (config, table->key, xstrdup (table->default_value)); else str_map_set (config, table->key, NULL); } static bool read_config_file (struct str_map *config, struct error **e) { char *filename = resolve_config_filename (PROGRAM_NAME ".conf"); if (!filename) return true; FILE *fp = fopen (filename, "r"); if (!fp) { error_set (e, "could not open `%s' for reading: %s", filename, strerror (errno)); return false; } struct str line; str_init (&line); bool errors = false; for (unsigned line_no = 1; read_line (fp, &line); line_no++) { char *start = line.str; if (*start == '#') continue; while (isspace (*start)) start++; char *end = strchr (start, '='); if (end) { char *value = end + 1; do *end = '\0'; while (isspace (*--end)); str_map_set (config, start, xstrdup (value)); } else if (*start) { error_set (e, "line %u in config: %s", line_no, "malformed input"); errors = true; break; } } str_free (&line); fclose (fp); return !errors; } static char * write_default_config (const char *filename, const char *prolog, const struct config_item *table, struct error **e) { struct str path, base; str_init (&path); str_init (&base); if (filename) { char *tmp = xstrdup (filename); str_append (&path, dirname (tmp)); strcpy (tmp, filename); str_append (&base, basename (tmp)); free (tmp); } else { get_xdg_home_dir (&path, "XDG_CONFIG_HOME", ".config"); str_append (&path, "/" PROGRAM_NAME); str_append (&base, PROGRAM_NAME ".conf"); } if (!mkdir_with_parents (path.str, e)) goto error; str_append_c (&path, '/'); str_append_str (&path, &base); FILE *fp = fopen (path.str, "w"); if (!fp) { error_set (e, "could not open `%s' for writing: %s", path.str, strerror (errno)); goto error; } if (prolog) fputs (prolog, fp); errno = 0; for (; table->key != NULL; table++) { fprintf (fp, "# %s\n", table->description); if (table->default_value) fprintf (fp, "%s=%s\n", table->key, table->default_value); else fprintf (fp, "#%s=\n", table->key); } fclose (fp); if (errno) { error_set (e, "writing to `%s' failed: %s", path.str, strerror (errno)); goto error; } str_free (&base); return str_steal (&path); error: str_free (&base); str_free (&path); return NULL; } static void call_write_default_config (const char *hint, const struct config_item *table) { static const char *prolog = "# " PROGRAM_NAME " " PROGRAM_VERSION " configuration file\n" "#\n" "# Relative paths are searched for in ${XDG_CONFIG_HOME:-~/.config}\n" "# /" PROGRAM_NAME " as well as in $XDG_CONFIG_DIRS/" PROGRAM_NAME "\n" "\n"; struct error *e = NULL; char *filename = write_default_config (hint, prolog, table, &e); if (!filename) { print_error ("%s", e->message); error_free (e); exit (EXIT_FAILURE); } print_status ("configuration written to `%s'", filename); free (filename); } // --- Option handler ---------------------------------------------------------- // Simple wrapper for the getopt_long API to make it easier to use and maintain. #define OPT_USAGE_ALIGNMENT_COLUMN 30 ///< Alignment for option descriptions enum { OPT_OPTIONAL_ARG = (1 << 0), ///< The argument is optional OPT_LONG_ONLY = (1 << 1) ///< Ignore the short name in opt_string }; // All options need to have both a short name, and a long name. The short name // is what is returned from opt_handler_get(). It is possible to define a value // completely out of the character range combined with the OPT_LONG_ONLY flag. // // When `arg_hint' is defined, the option is assumed to have an argument. struct opt { int short_name; ///< The single-letter name const char *long_name; ///< The long name const char *arg_hint; ///< Option argument hint int flags; ///< Option flags const char *description; ///< Option description }; struct opt_handler { int argc; ///< The number of program arguments char **argv; ///< Program arguments const char *arg_hint; ///< Program arguments hint const char *description; ///< Description of the program const struct opt *opts; ///< The list of options size_t opts_len; ///< The length of the option array struct option *options; ///< The list of options for getopt char *opt_string; ///< The `optstring' for getopt }; static void opt_handler_free (struct opt_handler *self) { free (self->options); free (self->opt_string); } static void opt_handler_init (struct opt_handler *self, int argc, char **argv, const struct opt *opts, const char *arg_hint, const char *description) { memset (self, 0, sizeof *self); self->argc = argc; self->argv = argv; self->arg_hint = arg_hint; self->description = description; size_t len = 0; for (const struct opt *iter = opts; iter->long_name; iter++) len++; self->opts = opts; self->opts_len = len; self->options = xcalloc (len + 1, sizeof *self->options); struct str opt_string; str_init (&opt_string); for (size_t i = 0; i < len; i++) { const struct opt *opt = opts + i; struct option *mapped = self->options + i; mapped->name = opt->long_name; if (!opt->arg_hint) mapped->has_arg = no_argument; else if (opt->flags & OPT_OPTIONAL_ARG) mapped->has_arg = optional_argument; else mapped->has_arg = required_argument; mapped->val = opt->short_name; if (opt->flags & OPT_LONG_ONLY) continue; str_append_c (&opt_string, opt->short_name); if (opt->arg_hint) { str_append_c (&opt_string, ':'); if (opt->flags & OPT_OPTIONAL_ARG) str_append_c (&opt_string, ':'); } } self->opt_string = str_steal (&opt_string); } static void opt_handler_usage (struct opt_handler *self, FILE *stream) { struct str usage; str_init (&usage); str_append_printf (&usage, "Usage: %s [OPTION]... %s\n", self->argv[0], self->arg_hint ? self->arg_hint : ""); str_append_printf (&usage, "%s\n\n", self->description); for (size_t i = 0; i < self->opts_len; i++) { struct str row; str_init (&row); const struct opt *opt = self->opts + i; if (!(opt->flags & OPT_LONG_ONLY)) str_append_printf (&row, " -%c, ", opt->short_name); else str_append (&row, " "); str_append_printf (&row, "--%s", opt->long_name); if (opt->arg_hint) str_append_printf (&row, (opt->flags & OPT_OPTIONAL_ARG) ? " [%s]" : " %s", opt->arg_hint); // TODO: keep the indent if there are multiple lines if (row.len + 2 <= OPT_USAGE_ALIGNMENT_COLUMN) { str_append (&row, " "); str_append_printf (&usage, "%-*s%s\n", OPT_USAGE_ALIGNMENT_COLUMN, row.str, opt->description); } else str_append_printf (&usage, "%s\n%-*s%s\n", row.str, OPT_USAGE_ALIGNMENT_COLUMN, "", opt->description); str_free (&row); } fputs (usage.str, stream); str_free (&usage); } static int opt_handler_get (struct opt_handler *self) { return getopt_long (self->argc, self->argv, self->opt_string, self->options, NULL); }