xK/common.c

1996 lines
46 KiB
C

/*
* common.c: common functionality
*
* Copyright (c) 2014, Přemysl Janouch <p.janouch@gmail.com>
* All rights reserved.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
*/
#define _POSIX_C_SOURCE 199309L
#define _XOPEN_SOURCE 600
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <stdarg.h>
#include <stdint.h>
#include <stdbool.h>
#include <ctype.h>
#include <time.h>
#include <limits.h>
#include <unistd.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <fcntl.h>
#include <poll.h>
#include <signal.h>
#include <strings.h>
#include <regex.h>
#include <libgen.h>
#include <syslog.h>
#include <fnmatch.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>
#ifndef NI_MAXHOST
#define NI_MAXHOST 1025
#endif // ! NI_MAXHOST
#ifndef NI_MAXSERV
#define NI_MAXSERV 32
#endif // ! NI_MAXSERV
#include <getopt.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include "siphash.h"
extern char **environ;
#ifdef _POSIX_MONOTONIC_CLOCK
#define CLOCK_BEST CLOCK_MONOTONIC
#else // ! _POSIX_MONOTIC_CLOCK
#define CLOCK_BEST CLOCK_REALTIME
#endif // ! _POSIX_MONOTONIC_CLOCK
#if defined __GNUC__
#define ATTRIBUTE_PRINTF(x, y) __attribute__ ((format (printf, x, y)))
#else // ! __GNUC__
#define ATTRIBUTE_PRINTF(x, y)
#endif // ! __GNUC__
#if defined __GNUC__ && __GNUC__ >= 4
#define ATTRIBUTE_SENTINEL __attribute__ ((sentinel))
#else // ! __GNUC__ || __GNUC__ < 4
#define ATTRIBUTE_SENTINEL
#endif // ! __GNUC__ || __GNUC__ < 4
#define N_ELEMENTS(a) (sizeof (a) / sizeof ((a)[0]))
#define BLOCK_START do {
#define BLOCK_END } while (0)
// --- Logging -----------------------------------------------------------------
static void
log_message_syslog (int prio, const char *quote, const char *fmt, va_list ap)
{
va_list va;
va_copy (va, ap);
int size = vsnprintf (NULL, 0, fmt, va);
va_end (va);
if (size < 0)
return;
char buf[size + 1];
if (vsnprintf (buf, sizeof buf, fmt, ap) >= 0)
syslog (prio, "%s%s", quote, buf);
}
static void
log_message_stdio (int prio, const char *quote, const char *fmt, va_list ap)
{
(void) prio;
FILE *stream = stderr;
fputs (quote, stream);
vfprintf (stream, fmt, ap);
fputs ("\n", stream);
}
static void (*g_log_message_real) (int, const char *, const char *, va_list)
= log_message_stdio;
static void
log_message (int priority, const char *quote, const char *fmt, ...)
ATTRIBUTE_PRINTF (3, 4);
static void
log_message (int priority, const char *quote, const char *fmt, ...)
{
va_list ap;
va_start (ap, fmt);
g_log_message_real (priority, quote, fmt, ap);
va_end (ap);
}
// `fatal' is reserved for unexpected failures that would harm further operation
#define print_fatal(...) log_message (LOG_ERR, "fatal: ", __VA_ARGS__)
#define print_error(...) log_message (LOG_ERR, "error: ", __VA_ARGS__)
#define print_warning(...) log_message (LOG_WARNING, "warning: ", __VA_ARGS__)
#define print_status(...) log_message (LOG_INFO, "-- ", __VA_ARGS__)
#define exit_fatal(...) \
BLOCK_START \
print_fatal (__VA_ARGS__); \
exit (EXIT_FAILURE); \
BLOCK_END
// --- Debugging and assertions ------------------------------------------------
// We should check everything that may possibly fail with at least a soft
// assertion, so that any causes for problems don't slip us by silently.
//
// `g_soft_asserts_are_deadly' may be useful while running inside a debugger.
static bool g_debug_mode; ///< Debug messages are printed
static bool g_soft_asserts_are_deadly; ///< soft_assert() aborts as well
#define print_debug(...) \
BLOCK_START \
if (g_debug_mode) \
log_message (LOG_DEBUG, "debug: ", __VA_ARGS__); \
BLOCK_END
static void
assertion_failure_handler (bool is_fatal, const char *file, int line,
const char *function, const char *condition)
{
if (is_fatal)
{
print_fatal ("assertion failed [%s:%d in function %s]: %s",
file, line, function, condition);
abort ();
}
else
print_debug ("assertion failed [%s:%d in function %s]: %s",
file, line, function, condition);
}
#define soft_assert(condition) \
((condition) ? true : \
(assertion_failure_handler (g_soft_asserts_are_deadly, \
__FILE__, __LINE__, __func__, #condition), false))
#define hard_assert(condition) \
((condition) ? (void) 0 : \
assertion_failure_handler (true, \
__FILE__, __LINE__, __func__, #condition))
// --- Safe memory management --------------------------------------------------
// When a memory allocation fails and we need the memory, we're usually pretty
// much fucked. Use the non-prefixed versions when there's a legitimate
// worry that an unrealistic amount of memory may be requested for allocation.
// XXX: it's not a good idea to use print_message() as it may want to allocate
// further memory for printf() and the output streams. That may fail.
static void *
xmalloc (size_t n)
{
void *p = malloc (n);
if (!p)
exit_fatal ("malloc: %s", strerror (errno));
return p;
}
static void *
xcalloc (size_t n, size_t m)
{
void *p = calloc (n, m);
if (!p && n && m)
exit_fatal ("calloc: %s", strerror (errno));
return p;
}
static void *
xrealloc (void *o, size_t n)
{
void *p = realloc (o, n);
if (!p && n)
exit_fatal ("realloc: %s", strerror (errno));
return p;
}
static void *
xreallocarray (void *o, size_t n, size_t m)
{
if (m && n > SIZE_MAX / m)
{
errno = ENOMEM;
exit_fatal ("reallocarray: %s", strerror (errno));
}
return xrealloc (o, n * m);
}
static char *
xstrdup (const char *s)
{
return strcpy (xmalloc (strlen (s) + 1), s);
}
static char *
xstrndup (const char *s, size_t n)
{
size_t size = strlen (s);
if (n > size)
n = size;
char *copy = xmalloc (n + 1);
memcpy (copy, s, n);
copy[n] = '\0';
return copy;
}
// --- Double-linked list helpers ----------------------------------------------
#define LIST_HEADER(type) \
struct type *next; \
struct type *prev;
#define LIST_PREPEND(head, link) \
BLOCK_START \
(link)->prev = NULL; \
(link)->next = (head); \
if ((link)->next) \
(link)->next->prev = (link); \
(head) = (link); \
BLOCK_END
#define LIST_UNLINK(head, link) \
BLOCK_START \
if ((link)->prev) \
(link)->prev->next = (link)->next; \
else \
(head) = (link)->next; \
if ((link)->next) \
(link)->next->prev = (link)->prev; \
BLOCK_END
// --- Dynamically allocated string array --------------------------------------
struct str_vector
{
char **vector;
size_t len;
size_t alloc;
};
static void
str_vector_init (struct str_vector *self)
{
self->alloc = 4;
self->len = 0;
self->vector = xcalloc (sizeof *self->vector, self->alloc);
}
static void
str_vector_free (struct str_vector *self)
{
unsigned i;
for (i = 0; i < self->len; i++)
free (self->vector[i]);
free (self->vector);
self->vector = NULL;
}
static void
str_vector_reset (struct str_vector *self)
{
str_vector_free (self);
str_vector_init (self);
}
static void
str_vector_add_owned (struct str_vector *self, char *s)
{
self->vector[self->len] = s;
if (++self->len >= self->alloc)
self->vector = xreallocarray (self->vector,
sizeof *self->vector, (self->alloc <<= 1));
self->vector[self->len] = NULL;
}
static void
str_vector_add (struct str_vector *self, const char *s)
{
str_vector_add_owned (self, xstrdup (s));
}
static void
str_vector_add_args (struct str_vector *self, const char *s, ...)
ATTRIBUTE_SENTINEL;
static void
str_vector_add_args (struct str_vector *self, const char *s, ...)
{
va_list ap;
va_start (ap, s);
while (s)
{
str_vector_add (self, s);
s = va_arg (ap, const char *);
}
va_end (ap);
}
static void
str_vector_add_vector (struct str_vector *self, char **vector)
{
while (*vector)
str_vector_add (self, *vector++);
}
static void
str_vector_remove (struct str_vector *self, size_t i)
{
hard_assert (i < self->len);
free (self->vector[i]);
memmove (self->vector + i, self->vector + i + 1,
(self->len-- - i) * sizeof *self->vector);
}
// --- Dynamically allocated strings -------------------------------------------
// Basically a string builder to abstract away manual memory management.
struct str
{
char *str; ///< String data, null terminated
size_t alloc; ///< How many bytes are allocated
size_t len; ///< How long the string actually is
};
/// We don't care about allocations that are way too large for the content, as
/// long as the allocation is below the given threshold. (Trivial heuristics.)
#define STR_SHRINK_THRESHOLD (1 << 20)
static void
str_init (struct str *self)
{
self->alloc = 16;
self->len = 0;
self->str = strcpy (xmalloc (self->alloc), "");
}
static void
str_free (struct str *self)
{
free (self->str);
self->str = NULL;
self->alloc = 0;
self->len = 0;
}
static void
str_reset (struct str *self)
{
str_free (self);
str_init (self);
}
static char *
str_steal (struct str *self)
{
char *str = self->str;
self->str = NULL;
str_free (self);
return str;
}
static void
str_ensure_space (struct str *self, size_t n)
{
// We allocate at least one more byte for the terminating null character
size_t new_alloc = self->alloc;
while (new_alloc <= self->len + n)
new_alloc <<= 1;
if (new_alloc != self->alloc)
self->str = xrealloc (self->str, (self->alloc = new_alloc));
}
static void
str_append_data (struct str *self, const char *data, size_t n)
{
str_ensure_space (self, n);
memcpy (self->str + self->len, data, n);
self->len += n;
self->str[self->len] = '\0';
}
static void
str_append_c (struct str *self, char c)
{
str_append_data (self, &c, 1);
}
static void
str_append (struct str *self, const char *s)
{
str_append_data (self, s, strlen (s));
}
static void
str_append_str (struct str *self, const struct str *another)
{
str_append_data (self, another->str, another->len);
}
static int
str_append_vprintf (struct str *self, const char *fmt, va_list va)
{
va_list ap;
int size;
va_copy (ap, va);
size = vsnprintf (NULL, 0, fmt, ap);
va_end (ap);
if (size < 0)
return -1;
va_copy (ap, va);
str_ensure_space (self, size);
size = vsnprintf (self->str + self->len, self->alloc - self->len, fmt, ap);
va_end (ap);
if (size > 0)
self->len += size;
return size;
}
static int
str_append_printf (struct str *self, const char *fmt, ...)
ATTRIBUTE_PRINTF (2, 3);
static int
str_append_printf (struct str *self, const char *fmt, ...)
{
va_list ap;
va_start (ap, fmt);
int size = str_append_vprintf (self, fmt, ap);
va_end (ap);
return size;
}
static void
str_remove_slice (struct str *self, size_t start, size_t length)
{
size_t end = start + length;
hard_assert (end <= self->len);
memmove (self->str + start, self->str + end, self->len - end);
self->str[self->len -= length] = '\0';
// Shrink the string if the allocation becomes way too large
if (self->alloc >= STR_SHRINK_THRESHOLD && self->len < (self->alloc >> 2))
self->str = xrealloc (self->str, self->alloc >>= 2);
}
// --- Errors ------------------------------------------------------------------
// Error reporting utilities. Inspired by GError, only much simpler.
struct error
{
char *message; ///< Textual description of the event
};
static void
error_set (struct error **e, const char *message, ...) ATTRIBUTE_PRINTF (2, 3);
static void
error_set (struct error **e, const char *message, ...)
{
if (!e)
return;
va_list ap;
va_start (ap, message);
int size = vsnprintf (NULL, 0, message, ap);
va_end (ap);
hard_assert (size >= 0);
struct error *tmp = xmalloc (sizeof *tmp);
tmp->message = xmalloc (size + 1);
va_start (ap, message);
size = vsnprintf (tmp->message, size + 1, message, ap);
va_end (ap);
hard_assert (size >= 0);
soft_assert (*e == NULL);
*e = tmp;
}
static void
error_free (struct error *e)
{
free (e->message);
free (e);
}
static void
error_propagate (struct error **destination, struct error *source)
{
if (!destination)
{
error_free (source);
return;
}
soft_assert (*destination == NULL);
*destination = source;
}
// --- String hash map ---------------------------------------------------------
// The most basic <string, managed pointer> map (or associative array).
struct str_map_link
{
LIST_HEADER (str_map_link)
void *data; ///< Payload
size_t key_length; ///< Length of the key without '\0'
char key[]; ///< The key for this link
};
struct str_map
{
struct str_map_link **map; ///< The hash table data itself
size_t alloc; ///< Number of allocated entries
size_t len; ///< Number of entries in the table
void (*free) (void *); ///< Callback to destruct the payload
/// Callback that transforms all key values for storage and comparison;
/// has to behave exactly like strxfrm().
size_t (*key_xfrm) (char *dest, const char *src, size_t n);
};
// As long as you don't remove the current entry, you can modify the map.
// Use `link' directly to access the data.
struct str_map_iter
{
struct str_map *map; ///< The map we're iterating
size_t next_index; ///< Next table index to search
struct str_map_link *link; ///< Current link
};
#define STR_MAP_MIN_ALLOC 16
typedef void (*str_map_free_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 <key, value> pair
size_t key_length = strlen (key);
struct str_map_link *link = xmalloc (sizeof *link + key_length + 1);
link->data = value;
link->key_length = key_length;
memcpy (link->key, key, key_length + 1);
LIST_PREPEND (self->map[pos], link);
self->len++;
}
static void
str_map_set (struct str_map *self, const char *key, void *value)
{
if (!self->key_xfrm)
{
str_map_set_real (self, key, value);
return;
}
char tmp[self->key_xfrm (NULL, key, 0) + 1];
self->key_xfrm (tmp, key, sizeof tmp);
str_map_set_real (self, tmp, value);
}
static void *
str_map_find_real (struct str_map *self, const char *key)
{
struct str_map_link *iter = self->map[str_map_pos (self, key)];
for (; iter; iter = iter->next)
if (!strcmp (key, (const char *) iter + sizeof *iter))
return iter->data;
return NULL;
}
static void *
str_map_find (struct str_map *self, const char *key)
{
if (!self->key_xfrm)
return str_map_find_real (self, key);
char tmp[self->key_xfrm (NULL, key, 0) + 1];
self->key_xfrm (tmp, key, sizeof tmp);
return str_map_find_real (self, tmp);
}
// --- File descriptor utilities -----------------------------------------------
static void
set_cloexec (int fd)
{
soft_assert (fcntl (fd, F_SETFD, fcntl (fd, F_GETFD) | FD_CLOEXEC) != -1);
}
static bool
set_blocking (int fd, bool blocking)
{
int flags = fcntl (fd, F_GETFL);
hard_assert (flags != -1);
bool prev = !(flags & O_NONBLOCK);
if (blocking)
flags &= ~O_NONBLOCK;
else
flags |= O_NONBLOCK;
hard_assert (fcntl (fd, F_SETFL, flags) != -1);
return prev;
}
static void
xclose (int fd)
{
while (close (fd) == -1)
if (!soft_assert (errno == EINTR))
break;
}
// --- Polling -----------------------------------------------------------------
// Basically the poor man's GMainLoop/libev/libuv. It might make some sense
// to instead use those tested and proven libraries but we don't need much
// and it's interesting to implement.
// At the moment the FD's are stored in an unsorted array. This is not ideal
// complexity-wise but I don't think I have much of a choice with poll(),
// and neither with epoll for that matter.
//
// unsorted array sorted array
// search O(n) O(log n) [O(log log n)]
// insert by fd O(n) O(n)
// delete by fd O(n) O(n)
//
// Insertion in the unsorted array can be reduced to O(1) if I maintain a
// bitmap of present FD's but that's still not a huge win.
//
// I don't expect this to be much of an issue, as there are typically not going
// to be that many FD's to watch, and the linear approach is cache-friendly.
typedef void (*poller_dispatcher_fn) (const struct pollfd *, void *);
typedef void (*poller_timer_fn) (void *);
#define POLLER_MIN_ALLOC 16
struct poller_timer_info
{
int64_t when; ///< When is the timer to expire
poller_timer_fn 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_fn dispatcher, void *data)
{
// NOTE: there may be duplicates.
for (size_t i = 0; i < self->len; i++)
if (self->info[i].dispatcher == dispatcher
&& self->info[i].user_data == data)
return i;
return -1;
}
static ssize_t
poller_timers_find_by_data (struct poller_timers *self, void *data)
{
for (size_t i = 0; i < self->len; i++)
if (self->info[i].user_data == data)
return i;
return -1;
}
static void
poller_timers_add (struct poller_timers *self,
poller_timer_fn dispatcher, void *data, int timeout_ms)
{
if (self->len == self->alloc)
self->info = xreallocarray (self->info,
self->alloc <<= 1, sizeof *self->info);
self->info[self->len] = (struct poller_timer_info) {
.when = poller_timers_get_current_time () + timeout_ms,
.dispatcher = dispatcher, .user_data = data };
poller_timers_heapify_up (self, self->len++);
}
static int
poller_timers_get_poll_timeout (struct poller_timers *self)
{
if (!self->len)
return -1;
int64_t timeout = self->info->when - poller_timers_get_current_time ();
if (timeout <= 0)
return 0;
if (timeout > INT_MAX)
return INT_MAX;
return timeout;
}
#ifdef __linux__
// I don't really need this, I've basically implemented this just because I can.
#include <sys/epoll.h>
struct poller_info
{
int fd; ///< Our file descriptor
short events; ///< The poll() events we registered for
poller_dispatcher_fn dispatcher; ///< Event dispatcher
void *user_data; ///< User data
};
struct poller
{
int epoll_fd; ///< The epoll FD
struct poller_info **info; ///< Information associated with each FD
struct epoll_event *revents; ///< Output array for epoll_wait()
size_t len; ///< Number of polled descriptors
size_t alloc; ///< Number of entries allocated
struct poller_timers timers; ///< Timeouts
/// Index of the element in `revents' that's about to be dispatched next.
int dispatch_next;
/// The total number of entries stored in `revents' by epoll_wait().
int dispatch_total;
};
static void
poller_init (struct poller *self)
{
self->epoll_fd = epoll_create (POLLER_MIN_ALLOC);
hard_assert (self->epoll_fd != -1);
set_cloexec (self->epoll_fd);
self->len = 0;
self->alloc = POLLER_MIN_ALLOC;
self->info = xcalloc (self->alloc, sizeof *self->info);
self->revents = xcalloc (self->alloc, sizeof *self->revents);
poller_timers_init (&self->timers);
self->dispatch_next = 0;
self->dispatch_total = 0;
}
static void
poller_free (struct poller *self)
{
for (size_t i = 0; i < self->len; i++)
{
struct poller_info *info = self->info[i];
hard_assert (epoll_ctl (self->epoll_fd,
EPOLL_CTL_DEL, info->fd, (void *) "") != -1);
free (info);
}
poller_timers_free (&self->timers);
xclose (self->epoll_fd);
free (self->info);
free (self->revents);
}
static ssize_t
poller_find_by_fd (struct poller *self, int fd)
{
for (size_t i = 0; i < self->len; i++)
if (self->info[i]->fd == fd)
return i;
return -1;
}
static void
poller_ensure_space (struct poller *self)
{
if (self->len < self->alloc)
return;
self->alloc <<= 1;
hard_assert (self->alloc != 0);
self->revents = xreallocarray
(self->revents, sizeof *self->revents, self->alloc);
self->info = xreallocarray
(self->info, sizeof *self->info, self->alloc);
}
static short
poller_epoll_to_poll_events (uint32_t events)
{
short result = 0;
if (events & EPOLLIN) result |= POLLIN;
if (events & EPOLLOUT) result |= POLLOUT;
if (events & EPOLLERR) result |= POLLERR;
if (events & EPOLLHUP) result |= POLLHUP;
if (events & EPOLLPRI) result |= POLLPRI;
return result;
}
static uint32_t
poller_poll_to_epoll_events (short events)
{
uint32_t result = 0;
if (events & POLLIN) result |= EPOLLIN;
if (events & POLLOUT) result |= EPOLLOUT;
if (events & POLLERR) result |= EPOLLERR;
if (events & POLLHUP) result |= EPOLLHUP;
if (events & POLLPRI) result |= EPOLLPRI;
return result;
}
static void
poller_set (struct poller *self, int fd, short events,
poller_dispatcher_fn dispatcher, void *data)
{
ssize_t index = poller_find_by_fd (self, fd);
bool modifying = true;
if (index == -1)
{
poller_ensure_space (self);
self->info[index = self->len++] = xcalloc (1, sizeof **self->info);
modifying = false;
}
struct poller_info *info = self->info[index];
info->fd = fd;
info->events = events;
info->dispatcher = dispatcher;
info->user_data = data;
struct epoll_event event;
event.events = poller_poll_to_epoll_events (events);
event.data.ptr = info;
hard_assert (epoll_ctl (self->epoll_fd,
modifying ? EPOLL_CTL_MOD : EPOLL_CTL_ADD, fd, &event) != -1);
}
static void
poller_remove_from_dispatch (struct poller *self,
const struct poller_info *info)
{
if (!self->dispatch_total)
return;
int i;
for (i = self->dispatch_next; i < self->dispatch_total; i++)
if (self->revents[i].data.ptr == info)
break;
if (i == self->dispatch_total)
return;
if (i != --self->dispatch_total)
self->revents[i] = self->revents[self->dispatch_total];
}
static void
poller_remove_at_index (struct poller *self, size_t index)
{
hard_assert (index < self->len);
struct poller_info *info = self->info[index];
poller_remove_from_dispatch (self, info);
hard_assert (epoll_ctl (self->epoll_fd,
EPOLL_CTL_DEL, info->fd, (void *) "") != -1);
free (info);
if (index != --self->len)
self->info[index] = self->info[self->len];
}
static void
poller_run (struct poller *self)
{
// Not reentrant
hard_assert (!self->dispatch_total);
int n_fds;
do
n_fds = epoll_wait (self->epoll_fd, self->revents, self->len,
poller_timers_get_poll_timeout (&self->timers));
while (n_fds == -1 && errno == EINTR);
if (n_fds == -1)
exit_fatal ("%s: %s", "epoll", strerror (errno));
self->dispatch_next = 0;
self->dispatch_total = n_fds;
poller_timers_dispatch (&self->timers);
while (self->dispatch_next < self->dispatch_total)
{
struct epoll_event *revents = self->revents + self->dispatch_next;
struct poller_info *info = revents->data.ptr;
struct pollfd pfd;
pfd.fd = info->fd;
pfd.revents = poller_epoll_to_poll_events (revents->events);
pfd.events = info->events;
self->dispatch_next++;
info->dispatcher (&pfd, info->user_data);
}
self->dispatch_next = 0;
self->dispatch_total = 0;
}
#else // !__linux__
struct poller_info
{
poller_dispatcher_func dispatcher; ///< Event dispatcher
void *user_data; ///< User data
};
struct poller
{
struct pollfd *fds; ///< Polled descriptors
struct poller_info *fds_info; ///< Additional information for each FD
size_t len; ///< Number of polled descriptors
size_t alloc; ///< Number of entries allocated
struct poller_timers timers; ///< Timers
int dispatch_next; ///< The next dispatched FD or -1
};
static void
poller_init (struct poller *self)
{
self->alloc = POLLER_MIN_ALLOC;
self->len = 0;
self->fds = xcalloc (self->alloc, sizeof *self->fds);
self->fds_info = xcalloc (self->alloc, sizeof *self->fds_info);
poller_timers_init (&self->timers);
self->dispatch_next = -1;
}
static void
poller_free (struct poller *self)
{
free (self->fds);
free (self->fds_info);
poller_timers_free (&self->timers);
}
static ssize_t
poller_find_by_fd (struct poller *self, int fd)
{
for (size_t i = 0; i < self->len; i++)
if (self->fds[i].fd == fd)
return i;
return -1;
}
static void
poller_ensure_space (struct poller *self)
{
if (self->len < self->alloc)
return;
self->alloc <<= 1;
self->fds = xreallocarray (self->fds, sizeof *self->fds, self->alloc);
self->fds_info = xreallocarray
(self->fds_info, sizeof *self->fds_info, self->alloc);
}
static void
poller_set (struct poller *self, int fd, short events,
poller_dispatcher_func dispatcher, void *data)
{
ssize_t index = poller_find_by_fd (self, fd);
if (index == -1)
{
poller_ensure_space (self);
index = self->len++;
}
struct pollfd *new_entry = self->fds + index;
memset (new_entry, 0, sizeof *new_entry);
new_entry->fd = fd;
new_entry->events = events;
self->fds_info[index] = (struct poller_info) { dispatcher, data };
}
static void
poller_remove_at_index (struct poller *self, size_t index)
{
hard_assert (index < self->len);
if (index == --self->len)
return;
// Make sure that we don't disrupt the dispatch loop; kind of crude
if ((int) index < self->dispatch_next)
{
memmove (self->fds + index, self->fds + index + 1,
(self->len - index) * sizeof *self->fds);
memmove (self->fds_info + index, self->fds_info + index + 1,
(self->len - index) * sizeof *self->fds_info);
self->dispatch_next--;
}
else
{
self->fds[index] = self->fds[self->len];
self->fds_info[index] = self->fds_info[self->len];
}
}
static void
poller_run (struct poller *self)
{
// Not reentrant
hard_assert (self->dispatch_next == -1);
int result;
do
result = poll (self->fds, self->len,
poller_timers_get_poll_timeout (&self->timers));
while (result == -1 && errno == EINTR);
if (result == -1)
exit_fatal ("%s: %s", "poll", strerror (errno));
poller_timers_dispatch (&self->timers);
for (int i = 0; i < (int) self->len; )
{
struct pollfd pfd = self->fds[i];
struct poller_info *info = self->fds_info + i;
self->dispatch_next = ++i;
if (pfd.revents)
info->dispatcher (&pfd, info->user_data);
i = self->dispatch_next;
}
self->dispatch_next = -1;
}
#endif // !__linux__
// --- Utilities ---------------------------------------------------------------
static void
split_str_ignore_empty (const char *s, char delimiter, struct str_vector *out)
{
const char *begin = s, *end;
while ((end = strchr (begin, delimiter)))
{
if (begin != end)
str_vector_add_owned (out, xstrndup (begin, end - begin));
begin = ++end;
}
if (*begin)
str_vector_add (out, begin);
}
static char *
strip_str_in_place (char *s, const char *stripped_chars)
{
char *end = s + strlen (s);
while (end > s && strchr (stripped_chars, end[-1]))
*--end = '\0';
char *start = s + strspn (s, stripped_chars);
if (start > s)
memmove (s, start, end - start + 1);
return s;
}
static char *
join_str_vector (const struct str_vector *v, char delimiter)
{
if (!v->len)
return xstrdup ("");
struct str result;
str_init (&result);
str_append (&result, v->vector[0]);
for (size_t i = 1; i < v->len; i++)
str_append_printf (&result, "%c%s", delimiter, v->vector[i]);
return str_steal (&result);
}
static char *xstrdup_printf (const char *, ...) ATTRIBUTE_PRINTF (1, 2);
static char *
xstrdup_printf (const char *format, ...)
{
va_list ap;
struct str tmp;
str_init (&tmp);
va_start (ap, format);
str_append_vprintf (&tmp, format, ap);
va_end (ap);
return str_steal (&tmp);
}
static bool
str_append_env_path (struct str *output, const char *var, bool only_absolute)
{
const char *value = getenv (var);
if (!value || (only_absolute && *value != '/'))
return false;
str_append (output, value);
return true;
}
static void
get_xdg_home_dir (struct str *output, const char *var, const char *def)
{
str_reset (output);
if (!str_append_env_path (output, var, true))
{
str_append_env_path (output, "HOME", false);
str_append_c (output, '/');
str_append (output, def);
}
}
static void
get_xdg_config_dirs (struct str_vector *out)
{
struct str config_home;
str_init (&config_home);
get_xdg_home_dir (&config_home, "XDG_CONFIG_HOME", ".config");
str_vector_add (out, config_home.str);
str_free (&config_home);
const char *xdg_config_dirs;
if ((xdg_config_dirs = getenv ("XDG_CONFIG_DIRS")))
split_str_ignore_empty (xdg_config_dirs, ':', out);
}
static char *
resolve_config_filename (const char *filename)
{
// Absolute path is absolute
if (*filename == '/')
return xstrdup (filename);
struct str_vector paths;
str_vector_init (&paths);
get_xdg_config_dirs (&paths);
struct str file;
str_init (&file);
char *result = NULL;
for (unsigned i = 0; i < paths.len; i++)
{
// As per spec, relative paths are ignored
if (*paths.vector[i] != '/')
continue;
str_reset (&file);
str_append_printf (&file, "%s/" PROGRAM_NAME "/%s",
paths.vector[i], filename);
struct stat st;
if (!stat (file.str, &st))
{
result = str_steal (&file);
break;
}
}
str_vector_free (&paths);
str_free (&file);
return result;
}
static bool
ensure_directory_existence (const char *path, struct error **e)
{
struct stat st;
if (stat (path, &st))
{
if (mkdir (path, S_IRWXU | S_IRWXG | S_IRWXO))
{
error_set (e, "cannot create directory `%s': %s",
path, strerror (errno));
return false;
}
}
else if (!S_ISDIR (st.st_mode))
{
error_set (e, "cannot create directory `%s': %s",
path, "file exists but is not a directory");
return false;
}
return true;
}
static bool
mkdir_with_parents (char *path, struct error **e)
{
char *p = path;
// XXX: This is prone to the TOCTTOU problem. The solution would be to
// rewrite the function using the {mkdir,fstat}at() functions from
// POSIX.1-2008, ideally returning a file descriptor to the open
// directory, with the current code as a fallback. Or to use chdir().
while ((p = strchr (p + 1, '/')))
{
*p = '\0';
bool success = ensure_directory_existence (path, e);
*p = '/';
if (!success)
return false;
}
return ensure_directory_existence (path, e);
}
static bool
set_boolean_if_valid (bool *out, const char *s)
{
if (!strcasecmp (s, "yes")) *out = true;
else if (!strcasecmp (s, "no")) *out = false;
else if (!strcasecmp (s, "on")) *out = true;
else if (!strcasecmp (s, "off")) *out = false;
else if (!strcasecmp (s, "true")) *out = true;
else if (!strcasecmp (s, "false")) *out = false;
else return false;
return true;
}
static bool
xstrtoul (unsigned long *out, const char *s, int base)
{
char *end;
errno = 0;
*out = strtoul (s, &end, base);
return errno == 0 && !*end && end != s;
}
static bool
read_line (FILE *fp, struct str *s)
{
int c;
bool at_end = true;
str_reset (s);
while ((c = fgetc (fp)) != EOF)
{
at_end = false;
if (c == '\r')
continue;
if (c == '\n')
break;
str_append_c (s, c);
}
return !at_end;
}
#define XSSL_ERROR_TRY_AGAIN INT_MAX
/// A small wrapper around SSL_get_error() to simplify further handling
static int
xssl_get_error (SSL *ssl, int result, const char **error_info)
{
int error = SSL_get_error (ssl, result);
switch (error)
{
case SSL_ERROR_NONE:
case SSL_ERROR_ZERO_RETURN:
case SSL_ERROR_WANT_READ:
case SSL_ERROR_WANT_WRITE:
return error;
case SSL_ERROR_SYSCALL:
if ((error = ERR_get_error ()))
*error_info = ERR_error_string (error, NULL);
else if (result == 0)
// An EOF that's not according to the protocol is still an EOF
return SSL_ERROR_ZERO_RETURN;
else
{
if (errno == EINTR)
return XSSL_ERROR_TRY_AGAIN;
*error_info = strerror (errno);
}
return SSL_ERROR_SSL;
default:
if ((error = ERR_get_error ()))
*error_info = ERR_error_string (error, NULL);
else
*error_info = "Unknown error";
return SSL_ERROR_SSL;
}
}
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;
}
// --- IRC utilities -----------------------------------------------------------
struct irc_message
{
struct str_map tags; ///< IRC 3.2 message tags
char *prefix; ///< Message prefix
char *command; ///< IRC command
struct str_vector params; ///< Command parameters
};
static void
irc_parse_message_tags (const char *tags, struct str_map *out)
{
struct str_vector v;
str_vector_init (&v);
split_str_ignore_empty (tags, ';', &v);
for (size_t i = 0; i < v.len; i++)
{
char *key = v.vector[i], *equal_sign = strchr (key, '=');
if (equal_sign)
{
*equal_sign = '\0';
str_map_set (out, key, xstrdup (equal_sign + 1));
}
else
str_map_set (out, key, xstrdup (""));
}
str_vector_free (&v);
}
static void
irc_parse_message (struct irc_message *msg, const char *line)
{
str_map_init (&msg->tags);
msg->tags.free = free;
msg->prefix = NULL;
msg->command = NULL;
str_vector_init (&msg->params);
// IRC 3.2 message tags
if (*line == '@')
{
size_t tags_len = strcspn (++line, " ");
char *tags = xstrndup (line, tags_len);
irc_parse_message_tags (tags, &msg->tags);
free (tags);
line += tags_len;
while (*line == ' ')
line++;
}
// Prefix
if (*line == ':')
{
size_t prefix_len = strcspn (++line, " ");
msg->prefix = xstrndup (line, prefix_len);
line += prefix_len;
}
// Command name
{
while (*line == ' ')
line++;
size_t cmd_len = strcspn (line, " ");
msg->command = xstrndup (line, cmd_len);
line += cmd_len;
}
// Arguments
while (true)
{
while (*line == ' ')
line++;
if (*line == ':')
{
str_vector_add (&msg->params, ++line);
break;
}
size_t param_len = strcspn (line, " ");
if (!param_len)
break;
str_vector_add_owned (&msg->params, xstrndup (line, param_len));
line += param_len;
}
}
static void
irc_free_message (struct irc_message *msg)
{
str_map_free (&msg->tags);
free (msg->prefix);
free (msg->command);
str_vector_free (&msg->params);
}
static void
irc_process_buffer (struct str *buf,
void (*callback)(const struct irc_message *, const char *, void *),
void *user_data)
{
char *start = buf->str, *end = start + buf->len;
for (char *p = start; p + 1 < end; p++)
{
// Split the input on newlines
if (p[0] != '\r' || p[1] != '\n')
continue;
*p = 0;
struct irc_message msg;
irc_parse_message (&msg, start);
callback (&msg, start, user_data);
irc_free_message (&msg);
start = p + 2;
}
// XXX: we might want to just advance some kind of an offset to avoid
// moving memory around unnecessarily.
str_remove_slice (buf, 0, start - buf->str);
}
static int
irc_tolower (int c)
{
if (c == '[') return '{';
if (c == ']') return '}';
if (c == '\\') return '|';
if (c == '~') return '^';
return c >= 'A' && c <= 'Z' ? c + ('a' - 'A') : c;
}
static size_t
irc_strxfrm (char *dest, const char *src, size_t n)
{
size_t len = strlen (src);
while (n-- && (*dest++ = irc_tolower (*src++)))
;
return len;
}
static int
irc_strcmp (const char *a, const char *b)
{
int x;
while (*a || *b)
if ((x = irc_tolower (*a++) - irc_tolower (*b++)))
return x;
return 0;
}
static int
irc_fnmatch (const char *pattern, const char *string)
{
size_t pattern_size = strlen (pattern) + 1;
size_t string_size = strlen (string) + 1;
char x_pattern[pattern_size], x_string[string_size];
irc_strxfrm (x_pattern, pattern, pattern_size);
irc_strxfrm (x_string, string, string_size);
return fnmatch (x_pattern, x_string, 0);
}
// --- Configuration -----------------------------------------------------------
// The keys are stripped of surrounding whitespace, the values are not.
struct config_item
{
const char *key;
const char *default_value;
const char *description;
};
static void
load_config_defaults (struct str_map *config, const struct config_item *table)
{
for (; table->key != NULL; table++)
if (table->default_value)
str_map_set (config, table->key, xstrdup (table->default_value));
else
str_map_set (config, table->key, NULL);
}
static bool
read_config_file (struct str_map *config, struct error **e)
{
char *filename = resolve_config_filename (PROGRAM_NAME ".conf");
if (!filename)
return true;
FILE *fp = fopen (filename, "r");
if (!fp)
{
error_set (e, "could not open `%s' for reading: %s",
filename, strerror (errno));
return false;
}
struct str line;
str_init (&line);
bool errors = false;
for (unsigned line_no = 1; read_line (fp, &line); line_no++)
{
char *start = line.str;
if (*start == '#')
continue;
while (isspace (*start))
start++;
char *end = strchr (start, '=');
if (end)
{
char *value = end + 1;
do
*end = '\0';
while (isspace (*--end));
str_map_set (config, start, xstrdup (value));
}
else if (*start)
{
error_set (e, "line %u in config: %s", line_no, "malformed input");
errors = true;
break;
}
}
str_free (&line);
fclose (fp);
return !errors;
}
static char *
write_default_config (const char *filename, const char *prolog,
const struct config_item *table, struct error **e)
{
struct str path, base;
str_init (&path);
str_init (&base);
if (filename)
{
char *tmp = xstrdup (filename);
str_append (&path, dirname (tmp));
strcpy (tmp, filename);
str_append (&base, basename (tmp));
free (tmp);
}
else
{
get_xdg_home_dir (&path, "XDG_CONFIG_HOME", ".config");
str_append (&path, "/" PROGRAM_NAME);
str_append (&base, PROGRAM_NAME ".conf");
}
if (!mkdir_with_parents (path.str, e))
goto error;
str_append_c (&path, '/');
str_append_str (&path, &base);
FILE *fp = fopen (path.str, "w");
if (!fp)
{
error_set (e, "could not open `%s' for writing: %s",
path.str, strerror (errno));
goto error;
}
if (prolog)
fputs (prolog, fp);
errno = 0;
for (; table->key != NULL; table++)
{
fprintf (fp, "# %s\n", table->description);
if (table->default_value)
fprintf (fp, "%s=%s\n", table->key, table->default_value);
else
fprintf (fp, "#%s=\n", table->key);
}
fclose (fp);
if (errno)
{
error_set (e, "writing to `%s' failed: %s", path.str, strerror (errno));
goto error;
}
str_free (&base);
return str_steal (&path);
error:
str_free (&base);
str_free (&path);
return NULL;
}
static void
call_write_default_config (const char *hint, const struct config_item *table)
{
static const char *prolog =
"# " PROGRAM_NAME " " PROGRAM_VERSION " configuration file\n"
"#\n"
"# Relative paths are searched for in ${XDG_CONFIG_HOME:-~/.config}\n"
"# /" PROGRAM_NAME " as well as in $XDG_CONFIG_DIRS/" PROGRAM_NAME "\n"
"\n";
struct error *e = NULL;
char *filename = write_default_config (hint, prolog, table, &e);
if (!filename)
{
print_error ("%s", e->message);
error_free (e);
exit (EXIT_FAILURE);
}
print_status ("configuration written to `%s'", filename);
free (filename);
}