diff options
Diffstat (limited to 'src/syslog_async.c')
| -rw-r--r-- | src/syslog_async.c | 409 |
1 files changed, 0 insertions, 409 deletions
diff --git a/src/syslog_async.c b/src/syslog_async.c deleted file mode 100644 index 431e834f..00000000 --- a/src/syslog_async.c +++ /dev/null @@ -1,409 +0,0 @@ -/* syslog_async is Copyright (c) 2007 Simon Kelley - - This program is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation; version 2 dated June, 1991. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. -*/ - -#include <sys/types.h> -#include <sys/socket.h> -#include <sys/un.h> -#include <sys/file.h> -#include <sys/syslog.h> - -#include <sys/uio.h> -#include <sys/wait.h> -#include <netdb.h> -#include <string.h> -#include <time.h> -#include <unistd.h> -#include <errno.h> -#include <stdarg.h> -#include <stdlib.h> -#include <paths.h> -#include <stdio.h> -#include <ctype.h> - -#include "syslog_async.h" - -/* From RFC 3164 */ -#define MAX_MESSAGE 1024 - -#define DEF_BACKLOG 5 -#define DEF_DELAY 1000 /* doesn't come into effect until backlog > 10 */ - -static int log_fac = LOG_USER; -static int log_opts = LOG_ODELAY; -static const char *log_tag = "syslog"; -static int log_mask = 0xff; -static int log_backlog = DEF_BACKLOG; -static int log_delay = DEF_DELAY; - -static int log_fd = -1; -static int entries_alloced = 0; -static int entries_lost = 0; -static int connection_good = 1; - -struct log_entry { - int offset, length; - struct log_entry *next; - char payload[MAX_MESSAGE]; -}; - -static struct log_entry *entries = NULL; -static struct log_entry *free_entries = NULL; - -static int mksock(int type) -{ - int flags; - int fd = socket(AF_UNIX, type, 0); - - if (fd != -1) - { - if ((flags = fcntl(fd, F_GETFL)) == -1 || - fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1 || - (flags = fcntl(fd, F_GETFD)) == -1 || - fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1) - { - close(fd); - fd = -1; - } - } - return fd; -} - -void openlog_async(const char *ident, int option, int facility) -{ - if (ident) - log_tag = ident; - - log_opts = option; - - if (facility != 0 && (facility &~ LOG_FACMASK) == 0) - log_fac = facility; - - if (log_opts & LOG_NDELAY) - log_fd = mksock(SOCK_DGRAM); -} - -int setlogmask_async(int mask) -{ - int old = log_mask; - - if (mask != 0) - log_mask = mask; - - return old; -} - -void tunelog_async(int backlog, int delay) -{ - /* we need at least one buffer, and the - delay calculations overflow for more than 99 */ - if (backlog < 1) - backlog = 1; - else if (backlog > 99) - backlog = 99; - - /* don't lose existing buffers */ - if (backlog < entries_alloced) - log_backlog = entries_alloced; - else - log_backlog = backlog; - - if (delay < 0) - log_delay = 0; - else if (delay > 1000) - log_delay = 1000; - else - log_delay = delay; -} - -void closelog_async(void) -{ - /* maybe last chance to flush */ - log_write_async(); - - if (log_fd != -1) - { - close(log_fd); - log_fd = -1; - } - - /* restore defaults */ - log_fac = LOG_USER; - log_opts = LOG_ODELAY; - log_tag = "syslog"; - log_mask = 0xff; - - log_delay = DEF_DELAY; - - if (entries_alloced < DEF_BACKLOG) - log_backlog = entries_alloced; - else - log_backlog = DEF_BACKLOG; -} - -int log_fd_async(void) -{ - if (!entries || !connection_good) - return -1; - - return log_fd; -} - -void log_write_async(void) -{ - ssize_t rc; - int fd, tried_stream = 0; - struct log_entry *tmp; - - while (entries) - { - if (log_fd == -1 && - (log_fd = mksock(SOCK_DGRAM)) == -1) - goto fail; - - connection_good = 1; - - if ((rc = send(log_fd, - entries->payload + entries->offset, - entries->length, - MSG_NOSIGNAL)) != -1) - { - entries->length -= rc; - entries->offset += rc; - connection_good = 1; - - if (entries->length == 0) - goto free; - - continue; - } - - if (errno == EINTR) - continue; - - if (errno == EAGAIN) - return; - - /* *BSD, returns this instead of blocking? */ - if (errno == ENOBUFS) - { - connection_good = 0; - return; - } - - /* A stream socket closed at the other end goes into EPIPE - forever, close and re-open. */ - if (errno == EPIPE) - goto reopen_stream; - - if (errno == ECONNREFUSED || - errno == ENOTCONN || - errno == EDESTADDRREQ || - errno == ECONNRESET) - { - /* socket went (syslogd down?), try and reconnect. If we fail, - stop trying until the next call to my_syslog() - ECONNREFUSED -> connection went down - ENOTCONN -> nobody listening - (ECONNRESET, EDESTADDRREQ are *BSD equivalents) */ - - struct sockaddr_un logaddr; - - logaddr.sun_family = AF_LOCAL; - strncpy(logaddr.sun_path, _PATH_LOG, sizeof(logaddr.sun_path)); - - /* Got connection back? try again. */ - if (connect(log_fd, (struct sockaddr *)&logaddr, sizeof(logaddr)) != -1) - continue; - - /* errors from connect which mean we should keep trying */ - if (errno == ENOENT || - errno == EALREADY || - errno == ECONNREFUSED || - errno == EISCONN || - errno == EINTR || - errno == EAGAIN) - { - /* try again on next syslog() call */ - connection_good = 0; - return; - } - - /* we start with a SOCK_DGRAM socket, but syslog may want SOCK_STREAM */ - if (!tried_stream && errno == EPROTOTYPE) - { - reopen_stream: - tried_stream = 1; - close(log_fd); - if ((log_fd = mksock(SOCK_STREAM)) != -1) - continue; - } - } - - fail: - tried_stream = 0; - - /* give up - try to write to console if we've been asked - take care not to block in open() or write() */ - if ((log_opts & LOG_CONS) && - (fd = open(_PATH_CONSOLE, O_WRONLY | O_NONBLOCK, 0)) != -1) - { - char *start = strchr(entries->payload, '>') + 1; - int flags = fcntl(fd, F_GETFL); - - if (flags != -1) - fcntl(fd, F_SETFL, flags | O_NONBLOCK); - - entries->length -= start - entries->payload; - /* move down to remove the tag, and make room for the \r\n */ - memmove(entries->payload, start, entries->length); - entries->payload[entries->length - 1] = '\r'; - entries->payload[entries->length] = '\n'; - write(fd, entries->payload, entries->length + 1); - close(fd); - } - - free: - tmp = entries; - entries = tmp->next; - tmp->next = free_entries; - free_entries = tmp; - - if (entries_lost != 0) - { - int e = entries_lost; - entries_lost = 0; /* avoid wild recursion */ - syslog_async(LOG_WARNING, "async_syslog overflow: %d log entries lost", e); - } - continue; - } -} - -void syslog_async(int priority, const char *format, ...) -{ - va_list ap; - - va_start(ap, format); - vsyslog_async(priority, format, ap); - va_end(ap); -} - -void vsyslog_async(int priority, const char *format, va_list ap) -{ - struct log_entry *entry; - time_t time_now; - char *p, *q, *r; - size_t len; - - if (!(log_mask & LOG_MASK(LOG_PRI(priority))) || (priority &~ (LOG_PRIMASK|LOG_FACMASK))) - return; - - if ((entry = free_entries)) - free_entries = entry->next; - else if (entries_alloced < log_backlog && (entry = malloc(sizeof(struct log_entry)))) - entries_alloced++; - - if (!entry) - entries_lost++; - else - { - /* add to end of list, consumed from the start */ - entry->next = NULL; - if (!entries) - entries = entry; - else - { - struct log_entry *tmp; - for (tmp = entries; tmp->next; tmp = tmp->next); - tmp->next = entry; - } - - time(&time_now); - p = entry->payload; - p += sprintf(p, "<%d>", priority | log_fac); - - q = p; - - if (log_opts & LOG_PID) - p += sprintf(p, "%.15s %s[%d]: ", ctime(&time_now) + 4, log_tag, getpid()); - else - p += sprintf(p, "%.15s %s: ", ctime(&time_now) + 4, log_tag); - - len = p - entry->payload; - len += vsnprintf(p, MAX_MESSAGE - len, format, ap) + 1; /* include zero-terminator */ - entry->length = len > MAX_MESSAGE ? MAX_MESSAGE : len; - - /* remove trailing '\n's passed to us. */ - for (r = &entry->payload[entry->length - 2]; r >= entry->payload; r--) - if (*r == '\n') - entry->length--; - else - break; - - entry->offset = 0; - - if (log_opts & LOG_PERROR) - { - ssize_t rc, s = entry->length - (q - entry->payload); - /* replace terminator with \n */ - entry->payload[entry->length - 1] = '\n'; - - while (s != 0) - if ((rc = write(STDERR_FILENO, q, s)) != -1) - { - s -= rc; - q += rc; - continue; - } - else if (errno == EINTR) - continue; - else - break; - } - entry->payload[entry->length - 1] = 0; - } - - /* almost always, logging won't block, so try and write this now, - to save collecting too many log messages during a select loop. */ - log_write_async(); - - /* Since we're doing things asynchronously, we - can now generate log lines very fast. With a small buffer (desirable), - that means it can overflow the log-buffer very quickly. - To avoid this, we delay here, the delay growing exponentially - with queue length. Delay is limited to 1 second, by default - but can be tuned for less if needed. Note that for a responsive - syslog, the log-line we just created will have been writen by the - call the log_write_async() above, so that this doesn't delay at all. */ - if (entries && log_delay != 0) - { - struct timespec waiter; - int d; - - for (d = 1,entry = entries; entry->next; entry = entry->next) - { - d *= 2; - if (d >= log_delay) /* limit to 999ms */ - { - d = log_delay - 1; - break; - } - } - - waiter.tv_sec = 0; - waiter.tv_nsec = d * 1000000; /* 1 ms */ - nanosleep(&waiter, NULL); - - /* try and write again */ - log_write_async(); - } -} - |