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busybox/sysklogd/syslogd.c
Denys Vlasenko 0288b27ad8 small fixes atop syslog config patch 
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
2011-04-16 20:15:14 +02:00

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/* vi: set sw=4 ts=4: */
/*
* Mini syslogd implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org>
*
* "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@gena01.com>
*
* Maintainer: Gennady Feldman <gfeldman@gena01.com> as of Mar 12, 2001
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//usage:#define syslogd_trivial_usage
//usage: "[OPTIONS]"
//usage:#define syslogd_full_usage "\n\n"
//usage: "System logging utility.\n"
//usage: "This version of syslogd ignores /etc/syslog.conf\n"
//usage: "\nOptions:"
//usage: "\n -n Run in foreground"
//usage: "\n -O FILE Log to given file (default:/var/log/messages)"
//usage: "\n -l N Set local log level"
//usage: "\n -S Smaller logging output"
//usage: IF_FEATURE_ROTATE_LOGFILE(
//usage: "\n -s SIZE Max size (KB) before rotate (default:200KB, 0=off)"
//usage: "\n -b N N rotated logs to keep (default:1, max=99, 0=purge)")
//usage: IF_FEATURE_REMOTE_LOG(
//usage: "\n -R HOST[:PORT] Log to IP or hostname on PORT (default PORT=514/UDP)"
//usage: "\n -L Log locally and via network (default is network only if -R)")
//usage: IF_FEATURE_SYSLOGD_DUP(
//usage: "\n -D Drop duplicates")
//usage: IF_FEATURE_IPC_SYSLOG(
//usage: "\n -C[size(KiB)] Log to shared mem buffer (read it using logread)")
//usage: IF_FEATURE_SYSLOGD_CFG(
//usage: "\n -f FILE Use FILE as config (default is /etc/syslog.conf)")
/* NB: -Csize shouldn't have space (because size is optional) */
/* //usage: "\n -m MIN Minutes between MARK lines (default:20, 0=off)" */
//usage:
//usage:#define syslogd_example_usage
//usage: "$ syslogd -R masterlog:514\n"
//usage: "$ syslogd -R 192.168.1.1:601\n"
/*
* Done in syslogd_and_logger.c:
#include "libbb.h"
#define SYSLOG_NAMES
#define SYSLOG_NAMES_CONST
#include <syslog.h>
*/
#include <sys/un.h>
#include <sys/uio.h>
#if ENABLE_FEATURE_REMOTE_LOG
#include <netinet/in.h>
#endif
#if ENABLE_FEATURE_IPC_SYSLOG
#include <sys/ipc.h>
#include <sys/sem.h>
#include <sys/shm.h>
#endif
#define DEBUG 0
/* MARK code is not very useful, is bloat, and broken:
* can deadlock if alarmed to make MARK while writing to IPC buffer
* (semaphores are down but do_mark routine tries to down them again) */
#undef SYSLOGD_MARK
/* Write locking does not seem to be useful either */
#undef SYSLOGD_WRLOCK
enum {
MAX_READ = CONFIG_FEATURE_SYSLOGD_READ_BUFFER_SIZE,
DNS_WAIT_SEC = 2 * 60,
};
/* Semaphore operation structures */
struct shbuf_ds {
int32_t size; /* size of data - 1 */
int32_t tail; /* end of message list */
char data[1]; /* data/messages */
};
#if ENABLE_FEATURE_REMOTE_LOG
typedef struct {
int remoteFD;
unsigned last_dns_resolve;
len_and_sockaddr *remoteAddr;
const char *remoteHostname;
} remoteHost_t;
#endif
typedef struct logFile_t {
const char *path;
int fd;
#if ENABLE_FEATURE_ROTATE_LOGFILE
unsigned size;
uint8_t isRegular;
#endif
} logFile_t;
#if ENABLE_FEATURE_SYSLOGD_CFG
typedef struct logRule_t {
uint8_t enabled_facility_priomap[LOG_NFACILITIES];
struct logFile_t *file;
struct logRule_t *next;
} logRule_t;
#endif
/* Allows us to have smaller initializer. Ugly. */
#define GLOBALS \
logFile_t logFile; \
/* interval between marks in seconds */ \
/*int markInterval;*/ \
/* level of messages to be logged */ \
int logLevel; \
IF_FEATURE_ROTATE_LOGFILE( \
/* max size of file before rotation */ \
unsigned logFileSize; \
/* number of rotated message files */ \
unsigned logFileRotate; \
) \
IF_FEATURE_IPC_SYSLOG( \
int shmid; /* ipc shared memory id */ \
int s_semid; /* ipc semaphore id */ \
int shm_size; \
struct sembuf SMwup[1]; \
struct sembuf SMwdn[3]; \
) \
IF_FEATURE_SYSLOGD_CFG( \
logRule_t *log_rules; \
)
struct init_globals {
GLOBALS
};
struct globals {
GLOBALS
#if ENABLE_FEATURE_REMOTE_LOG
llist_t *remoteHosts;
#endif
#if ENABLE_FEATURE_IPC_SYSLOG
struct shbuf_ds *shbuf;
#endif
time_t last_log_time;
/* localhost's name. We print only first 64 chars */
char *hostname;
/* We recv into recvbuf... */
char recvbuf[MAX_READ * (1 + ENABLE_FEATURE_SYSLOGD_DUP)];
/* ...then copy to parsebuf, escaping control chars */
/* (can grow x2 max) */
char parsebuf[MAX_READ*2];
/* ...then sprintf into printbuf, adding timestamp (15 chars),
* host (64), fac.prio (20) to the message */
/* (growth by: 15 + 64 + 20 + delims = ~110) */
char printbuf[MAX_READ*2 + 128];
};
static const struct init_globals init_data = {
.logFile = {
.path = "/var/log/messages",
.fd = -1,
},
#ifdef SYSLOGD_MARK
.markInterval = 20 * 60,
#endif
.logLevel = 8,
#if ENABLE_FEATURE_ROTATE_LOGFILE
.logFileSize = 200 * 1024,
.logFileRotate = 1,
#endif
#if ENABLE_FEATURE_IPC_SYSLOG
.shmid = -1,
.s_semid = -1,
.shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024), /* default shm size */
.SMwup = { {1, -1, IPC_NOWAIT} },
.SMwdn = { {0, 0}, {1, 0}, {1, +1} },
#endif
};
#define G (*ptr_to_globals)
#define INIT_G() do { \
SET_PTR_TO_GLOBALS(memcpy(xzalloc(sizeof(G)), &init_data, sizeof(init_data))); \
} while (0)
/* Options */
enum {
OPTBIT_mark = 0, // -m
OPTBIT_nofork, // -n
OPTBIT_outfile, // -O
OPTBIT_loglevel, // -l
OPTBIT_small, // -S
IF_FEATURE_ROTATE_LOGFILE(OPTBIT_filesize ,) // -s
IF_FEATURE_ROTATE_LOGFILE(OPTBIT_rotatecnt ,) // -b
IF_FEATURE_REMOTE_LOG( OPTBIT_remotelog ,) // -R
IF_FEATURE_REMOTE_LOG( OPTBIT_locallog ,) // -L
IF_FEATURE_IPC_SYSLOG( OPTBIT_circularlog,) // -C
IF_FEATURE_SYSLOGD_DUP( OPTBIT_dup ,) // -D
IF_FEATURE_SYSLOGD_CFG( OPTBIT_cfg ,) // -f
OPT_mark = 1 << OPTBIT_mark ,
OPT_nofork = 1 << OPTBIT_nofork ,
OPT_outfile = 1 << OPTBIT_outfile ,
OPT_loglevel = 1 << OPTBIT_loglevel,
OPT_small = 1 << OPTBIT_small ,
OPT_filesize = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_filesize )) + 0,
OPT_rotatecnt = IF_FEATURE_ROTATE_LOGFILE((1 << OPTBIT_rotatecnt )) + 0,
OPT_remotelog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_remotelog )) + 0,
OPT_locallog = IF_FEATURE_REMOTE_LOG( (1 << OPTBIT_locallog )) + 0,
OPT_circularlog = IF_FEATURE_IPC_SYSLOG( (1 << OPTBIT_circularlog)) + 0,
OPT_dup = IF_FEATURE_SYSLOGD_DUP( (1 << OPTBIT_dup )) + 0,
OPT_cfg = IF_FEATURE_SYSLOGD_CFG( (1 << OPTBIT_cfg )) + 0,
};
#define OPTION_STR "m:nO:l:S" \
IF_FEATURE_ROTATE_LOGFILE("s:" ) \
IF_FEATURE_ROTATE_LOGFILE("b:" ) \
IF_FEATURE_REMOTE_LOG( "R:" ) \
IF_FEATURE_REMOTE_LOG( "L" ) \
IF_FEATURE_IPC_SYSLOG( "C::") \
IF_FEATURE_SYSLOGD_DUP( "D" ) \
IF_FEATURE_SYSLOGD_CFG( "f:" )
#define OPTION_DECL *opt_m, *opt_l \
IF_FEATURE_ROTATE_LOGFILE(,*opt_s) \
IF_FEATURE_ROTATE_LOGFILE(,*opt_b) \
IF_FEATURE_IPC_SYSLOG( ,*opt_C = NULL) \
IF_FEATURE_SYSLOGD_CFG( ,*opt_f = NULL)
#define OPTION_PARAM &opt_m, &(G.logFile.path), &opt_l \
IF_FEATURE_ROTATE_LOGFILE(,&opt_s) \
IF_FEATURE_ROTATE_LOGFILE(,&opt_b) \
IF_FEATURE_REMOTE_LOG( ,&remoteAddrList) \
IF_FEATURE_IPC_SYSLOG( ,&opt_C) \
IF_FEATURE_SYSLOGD_CFG( ,&opt_f)
#if ENABLE_FEATURE_SYSLOGD_CFG
static const CODE* find_by_name(char *name, const CODE* c_set)
{
for (; c_set->c_name; c_set++) {
if (strcmp(name, c_set->c_name) == 0)
return c_set;
}
return NULL;
}
#endif
static const CODE* find_by_val(int val, const CODE* c_set)
{
for (; c_set->c_name; c_set++) {
if (c_set->c_val == val)
return c_set;
}
return NULL;
}
#if ENABLE_FEATURE_SYSLOGD_CFG
static void parse_syslogdcfg(const char *file)
{
char *t;
logRule_t **pp_rule;
/* tok[0] set of selectors */
/* tok[1] file name */
/* tok[2] has to be NULL */
char *tok[3];
parser_t *parser;
parser = config_open2(file ? file : "/etc/syslog.conf",
file ? xfopen_for_read : fopen_or_warn_stdin);
if (!parser)
/* didn't find default /etc/syslog.conf */
/* proceed as if we built busybox without config support */
return;
/* use ptr to ptr to avoid checking whether head was initialized */
pp_rule = &G.log_rules;
/* iterate through lines of config, skipping comments */
while (config_read(parser, tok, 3, 2, "# \t", PARSE_NORMAL | PARSE_MIN_DIE)) {
char *cur_selector;
logRule_t *cur_rule;
/* unexpected trailing token? */
if (tok[2])
goto cfgerr;
cur_rule = *pp_rule = xzalloc(sizeof(*cur_rule));
cur_selector = tok[0];
/* iterate through selectors: "kern.info;kern.!err;..." */
do {
const CODE *code;
char *next_selector;
uint8_t negated_prio; /* "kern.!err" */
uint8_t single_prio; /* "kern.=err" */
uint32_t facmap; /* bitmap of enabled facilities */
uint8_t primap; /* bitmap of enabled priorities */
unsigned i;
next_selector = strchr(cur_selector, ';');
if (next_selector)
*next_selector++ = '\0';
t = strchr(cur_selector, '.');
if (!t)
goto cfgerr;
*t++ = '\0'; /* separate facility from priority */
negated_prio = 0;
single_prio = 0;
if (*t == '!') {
negated_prio = 1;
++t;
}
if (*t == '=') {
single_prio = 1;
++t;
}
/* parse priority */
if (*t == '*')
primap = 0xff; /* all 8 log levels enabled */
else {
uint8_t priority;
code = find_by_name(t, prioritynames);
if (!code)
goto cfgerr;
primap = 0;
priority = code->c_val;
if (priority == INTERNAL_NOPRI) {
/* ensure we take "enabled_facility_priomap[fac] &= 0" branch below */
negated_prio = 1;
} else {
priority = 1 << priority;
do {
primap |= priority;
if (single_prio)
break;
priority >>= 1;
} while (priority);
if (negated_prio)
primap = ~primap;
}
}
/* parse facility */
if (*cur_selector == '*')
facmap = (1<<LOG_NFACILITIES) - 1;
else {
char *next_facility;
facmap = 0;
t = cur_selector;
/* iterate through facilities: "kern,daemon.<priospec>" */
do {
next_facility = strchr(t, ',');
if (next_facility)
*next_facility++ = '\0';
code = find_by_name(t, facilitynames);
if (!code)
goto cfgerr;
/* "mark" is not a real facility, skip it */
if (code->c_val != INTERNAL_MARK)
facmap |= 1<<(LOG_FAC(code->c_val));
t = next_facility;
} while (t);
}
/* merge result with previous selectors */
for (i = 0; i < LOG_NFACILITIES; ++i) {
if (!(facmap & (1<<i)))
continue;
if (negated_prio)
cur_rule->enabled_facility_priomap[i] &= primap;
else
cur_rule->enabled_facility_priomap[i] |= primap;
}
cur_selector = next_selector;
} while (cur_selector);
/* check whether current file name was mentioned in previous rules or
* as global logfile (G.logFile).
*/
if (strcmp(G.logFile.path, tok[1]) == 0) {
cur_rule->file = &G.logFile;
goto found;
}
/* temporarily use cur_rule as iterator, but *pp_rule still points
* to currently processing rule entry.
* NOTE: *pp_rule points to the current (and last in the list) rule.
*/
for (cur_rule = G.log_rules; cur_rule != *pp_rule; cur_rule = cur_rule->next) {
if (strcmp(cur_rule->file->path, tok[1]) == 0) {
/* found - reuse the same file structure */
(*pp_rule)->file = cur_rule->file;
cur_rule = *pp_rule;
goto found;
}
}
cur_rule->file = xzalloc(sizeof(*cur_rule->file));
cur_rule->file->fd = -1;
cur_rule->file->path = xstrdup(tok[1]);
found:
pp_rule = &cur_rule->next;
}
config_close(parser);
return;
cfgerr:
bb_error_msg_and_die("error in '%s' at line %d", file, parser->lineno);
}
#endif
/* circular buffer variables/structures */
#if ENABLE_FEATURE_IPC_SYSLOG
#if CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE < 4
#error Sorry, you must set the syslogd buffer size to at least 4KB.
#error Please check CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE
#endif
/* our shared key (syslogd.c and logread.c must be in sync) */
enum { KEY_ID = 0x414e4547 }; /* "GENA" */
static void ipcsyslog_cleanup(void)
{
if (G.shmid != -1) {
shmdt(G.shbuf);
}
if (G.shmid != -1) {
shmctl(G.shmid, IPC_RMID, NULL);
}
if (G.s_semid != -1) {
semctl(G.s_semid, 0, IPC_RMID, 0);
}
}
static void ipcsyslog_init(void)
{
if (DEBUG)
printf("shmget(%x, %d,...)\n", (int)KEY_ID, G.shm_size);
G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 0644);
if (G.shmid == -1) {
bb_perror_msg_and_die("shmget");
}
G.shbuf = shmat(G.shmid, NULL, 0);
if (G.shbuf == (void*) -1L) { /* shmat has bizarre error return */
bb_perror_msg_and_die("shmat");
}
memset(G.shbuf, 0, G.shm_size);
G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data) - 1;
/*G.shbuf->tail = 0;*/
/* we'll trust the OS to set initial semval to 0 (let's hope) */
G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
if (G.s_semid == -1) {
if (errno == EEXIST) {
G.s_semid = semget(KEY_ID, 2, 0);
if (G.s_semid != -1)
return;
}
bb_perror_msg_and_die("semget");
}
}
/* Write message to shared mem buffer */
static void log_to_shmem(const char *msg)
{
int old_tail, new_tail;
int len;
if (semop(G.s_semid, G.SMwdn, 3) == -1) {
bb_perror_msg_and_die("SMwdn");
}
/* Circular Buffer Algorithm:
* --------------------------
* tail == position where to store next syslog message.
* tail's max value is (shbuf->size - 1)
* Last byte of buffer is never used and remains NUL.
*/
len = strlen(msg) + 1; /* length with NUL included */
again:
old_tail = G.shbuf->tail;
new_tail = old_tail + len;
if (new_tail < G.shbuf->size) {
/* store message, set new tail */
memcpy(G.shbuf->data + old_tail, msg, len);
G.shbuf->tail = new_tail;
} else {
/* k == available buffer space ahead of old tail */
int k = G.shbuf->size - old_tail;
/* copy what fits to the end of buffer, and repeat */
memcpy(G.shbuf->data + old_tail, msg, k);
msg += k;
len -= k;
G.shbuf->tail = 0;
goto again;
}
if (semop(G.s_semid, G.SMwup, 1) == -1) {
bb_perror_msg_and_die("SMwup");
}
if (DEBUG)
printf("tail:%d\n", G.shbuf->tail);
}
#else
void ipcsyslog_cleanup(void);
void ipcsyslog_init(void);
void log_to_shmem(const char *msg);
#endif /* FEATURE_IPC_SYSLOG */
/* Print a message to the log file. */
static void log_locally(time_t now, char *msg, logFile_t *log_file)
{
#ifdef SYSLOGD_WRLOCK
struct flock fl;
#endif
int len = strlen(msg);
if (log_file->fd >= 0) {
/* Reopen log file every second. This allows admin
* to delete the file and not worry about restarting us.
* This costs almost nothing since it happens
* _at most_ once a second.
*/
if (!now)
now = time(NULL);
if (G.last_log_time != now) {
G.last_log_time = now;
close(log_file->fd);
goto reopen;
}
} else {
reopen:
log_file->fd = open(log_file->path, O_WRONLY | O_CREAT
| O_NOCTTY | O_APPEND | O_NONBLOCK,
0666);
if (log_file->fd < 0) {
/* cannot open logfile? - print to /dev/console then */
int fd = device_open(DEV_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
if (fd < 0)
fd = 2; /* then stderr, dammit */
full_write(fd, msg, len);
if (fd != 2)
close(fd);
return;
}
#if ENABLE_FEATURE_ROTATE_LOGFILE
{
struct stat statf;
log_file->isRegular = (fstat(log_file->fd, &statf) == 0 && S_ISREG(statf.st_mode));
/* bug (mostly harmless): can wrap around if file > 4gb */
log_file->size = statf.st_size;
}
#endif
}
#ifdef SYSLOGD_WRLOCK
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 1;
fl.l_type = F_WRLCK;
fcntl(log_file->fd, F_SETLKW, &fl);
#endif
#if ENABLE_FEATURE_ROTATE_LOGFILE
if (G.logFileSize && log_file->isRegular && log_file->size > G.logFileSize) {
if (G.logFileRotate) { /* always 0..99 */
int i = strlen(log_file->path) + 3 + 1;
char oldFile[i];
char newFile[i];
i = G.logFileRotate - 1;
/* rename: f.8 -> f.9; f.7 -> f.8; ... */
while (1) {
sprintf(newFile, "%s.%d", log_file->path, i);
if (i == 0) break;
sprintf(oldFile, "%s.%d", log_file->path, --i);
/* ignore errors - file might be missing */
rename(oldFile, newFile);
}
/* newFile == "f.0" now */
rename(log_file->path, newFile);
#ifdef SYSLOGD_WRLOCK
fl.l_type = F_UNLCK;
fcntl(log_file->fd, F_SETLKW, &fl);
#endif
close(log_file->fd);
goto reopen;
}
ftruncate(log_file->fd, 0);
}
log_file->size +=
#endif
full_write(log_file->fd, msg, len);
#ifdef SYSLOGD_WRLOCK
fl.l_type = F_UNLCK;
fcntl(log_file->fd, F_SETLKW, &fl);
#endif
}
static void parse_fac_prio_20(int pri, char *res20)
{
const CODE *c_pri, *c_fac;
c_fac = find_by_val(LOG_FAC(pri) << 3, facilitynames);
if (c_fac) {
c_pri = find_by_val(LOG_PRI(pri), prioritynames);
if (c_pri) {
snprintf(res20, 20, "%s.%s", c_fac->c_name, c_pri->c_name);
return;
}
}
snprintf(res20, 20, "<%d>", pri);
}
/* len parameter is used only for "is there a timestamp?" check.
* NB: some callers cheat and supply len==0 when they know
* that there is no timestamp, short-circuiting the test. */
static void timestamp_and_log(int pri, char *msg, int len)
{
char *timestamp;
time_t now;
/* Jan 18 00:11:22 msg... */
/* 01234567890123456 */
if (len < 16 || msg[3] != ' ' || msg[6] != ' '
|| msg[9] != ':' || msg[12] != ':' || msg[15] != ' '
) {
time(&now);
timestamp = ctime(&now) + 4; /* skip day of week */
} else {
now = 0;
timestamp = msg;
msg += 16;
}
timestamp[15] = '\0';
if (option_mask32 & OPT_small)
sprintf(G.printbuf, "%s %s\n", timestamp, msg);
else {
char res[20];
parse_fac_prio_20(pri, res);
sprintf(G.printbuf, "%s %.64s %s %s\n", timestamp, G.hostname, res, msg);
}
/* Log message locally (to file or shared mem) */
#if ENABLE_FEATURE_SYSLOGD_CFG
{
bool match = 0;
logRule_t *rule;
uint8_t facility = LOG_FAC(pri);
uint8_t prio_bit = 1 << LOG_PRI(pri);
for (rule = G.log_rules; rule; rule = rule->next) {
if (rule->enabled_facility_priomap[facility] & prio_bit) {
log_locally(now, G.printbuf, rule->file);
match = 1;
}
}
if (match)
return;
}
#endif
if (LOG_PRI(pri) < G.logLevel) {
#if ENABLE_FEATURE_IPC_SYSLOG
if ((option_mask32 & OPT_circularlog) && G.shbuf) {
log_to_shmem(msg);
return;
}
#endif
log_locally(now, G.printbuf, &G.logFile);
}
}
static void timestamp_and_log_internal(const char *msg)
{
/* -L, or no -R */
if (ENABLE_FEATURE_REMOTE_LOG && !(option_mask32 & OPT_locallog))
return;
timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)msg, 0);
}
/* tmpbuf[len] is a NUL byte (set by caller), but there can be other,
* embedded NULs. Split messages on each of these NULs, parse prio,
* escape control chars and log each locally. */
static void split_escape_and_log(char *tmpbuf, int len)
{
char *p = tmpbuf;
tmpbuf += len;
while (p < tmpbuf) {
char c;
char *q = G.parsebuf;
int pri = (LOG_USER | LOG_NOTICE);
if (*p == '<') {
/* Parse the magic priority number */
pri = bb_strtou(p + 1, &p, 10);
if (*p == '>')
p++;
if (pri & ~(LOG_FACMASK | LOG_PRIMASK))
pri = (LOG_USER | LOG_NOTICE);
}
while ((c = *p++)) {
if (c == '\n')
c = ' ';
if (!(c & ~0x1f) && c != '\t') {
*q++ = '^';
c += '@'; /* ^@, ^A, ^B... */
}
*q++ = c;
}
*q = '\0';
/* Now log it */
timestamp_and_log(pri, G.parsebuf, q - G.parsebuf);
}
}
#ifdef SYSLOGD_MARK
static void do_mark(int sig)
{
if (G.markInterval) {
timestamp_and_log_internal("-- MARK --");
alarm(G.markInterval);
}
}
#endif
/* Don't inline: prevent struct sockaddr_un to take up space on stack
* permanently */
static NOINLINE int create_socket(void)
{
struct sockaddr_un sunx;
int sock_fd;
char *dev_log_name;
#if ENABLE_FEATURE_SYSTEMD
if (sd_listen_fds() == 1)
return SD_LISTEN_FDS_START;
#endif
memset(&sunx, 0, sizeof(sunx));
sunx.sun_family = AF_UNIX;
/* Unlink old /dev/log or object it points to. */
/* (if it exists, bind will fail) */
strcpy(sunx.sun_path, "/dev/log");
dev_log_name = xmalloc_follow_symlinks("/dev/log");
if (dev_log_name) {
safe_strncpy(sunx.sun_path, dev_log_name, sizeof(sunx.sun_path));
free(dev_log_name);
}
unlink(sunx.sun_path);
sock_fd = xsocket(AF_UNIX, SOCK_DGRAM, 0);
xbind(sock_fd, (struct sockaddr *) &sunx, sizeof(sunx));
chmod("/dev/log", 0666);
return sock_fd;
}
#if ENABLE_FEATURE_REMOTE_LOG
static int try_to_resolve_remote(remoteHost_t *rh)
{
if (!rh->remoteAddr) {
unsigned now = monotonic_sec();
/* Don't resolve name too often - DNS timeouts can be big */
if ((now - rh->last_dns_resolve) < DNS_WAIT_SEC)
return -1;
rh->last_dns_resolve = now;
rh->remoteAddr = host2sockaddr(rh->remoteHostname, 514);
if (!rh->remoteAddr)
return -1;
}
return xsocket(rh->remoteAddr->u.sa.sa_family, SOCK_DGRAM, 0);
}
#endif
static void do_syslogd(void) NORETURN;
static void do_syslogd(void)
{
int sock_fd;
#if ENABLE_FEATURE_REMOTE_LOG
llist_t *item;
#endif
#if ENABLE_FEATURE_SYSLOGD_DUP
int last_sz = -1;
char *last_buf;
char *recvbuf = G.recvbuf;
#else
#define recvbuf (G.recvbuf)
#endif
/* Set up signal handlers (so that they interrupt read()) */
signal_no_SA_RESTART_empty_mask(SIGTERM, record_signo);
signal_no_SA_RESTART_empty_mask(SIGINT, record_signo);
//signal_no_SA_RESTART_empty_mask(SIGQUIT, record_signo);
signal(SIGHUP, SIG_IGN);
#ifdef SYSLOGD_MARK
signal(SIGALRM, do_mark);
alarm(G.markInterval);
#endif
sock_fd = create_socket();
if (ENABLE_FEATURE_IPC_SYSLOG && (option_mask32 & OPT_circularlog)) {
ipcsyslog_init();
}
timestamp_and_log_internal("syslogd started: BusyBox v" BB_VER);
while (!bb_got_signal) {
ssize_t sz;
#if ENABLE_FEATURE_SYSLOGD_DUP
last_buf = recvbuf;
if (recvbuf == G.recvbuf)
recvbuf = G.recvbuf + MAX_READ;
else
recvbuf = G.recvbuf;
#endif
read_again:
sz = read(sock_fd, recvbuf, MAX_READ - 1);
if (sz < 0) {
if (!bb_got_signal)
bb_perror_msg("read from /dev/log");
break;
}
/* Drop trailing '\n' and NULs (typically there is one NUL) */
while (1) {
if (sz == 0)
goto read_again;
/* man 3 syslog says: "A trailing newline is added when needed".
* However, neither glibc nor uclibc do this:
* syslog(prio, "test") sends "test\0" to /dev/log,
* syslog(prio, "test\n") sends "test\n\0".
* IOW: newline is passed verbatim!
* I take it to mean that it's syslogd's job
* to make those look identical in the log files. */
if (recvbuf[sz-1] != '\0' && recvbuf[sz-1] != '\n')
break;
sz--;
}
#if ENABLE_FEATURE_SYSLOGD_DUP
if ((option_mask32 & OPT_dup) && (sz == last_sz))
if (memcmp(last_buf, recvbuf, sz) == 0)
continue;
last_sz = sz;
#endif
#if ENABLE_FEATURE_REMOTE_LOG
/* Stock syslogd sends it '\n'-terminated
* over network, mimic that */
recvbuf[sz] = '\n';
/* We are not modifying log messages in any way before send */
/* Remote site cannot trust _us_ anyway and need to do validation again */
for (item = G.remoteHosts; item != NULL; item = item->link) {
remoteHost_t *rh = (remoteHost_t *)item->data;
if (rh->remoteFD == -1) {
rh->remoteFD = try_to_resolve_remote(rh);
if (rh->remoteFD == -1)
continue;
}
/* Send message to remote logger.
* On some errors, close and set remoteFD to -1
* so that DNS resolution is retried.
*/
if (sendto(rh->remoteFD, recvbuf, sz+1,
MSG_DONTWAIT | MSG_NOSIGNAL,
&(rh->remoteAddr->u.sa), rh->remoteAddr->len) == -1
) {
switch (errno) {
case ECONNRESET:
case ENOTCONN: /* paranoia */
case EPIPE:
close(rh->remoteFD);
rh->remoteFD = -1;
free(rh->remoteAddr);
rh->remoteAddr = NULL;
}
}
}
#endif
if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
recvbuf[sz] = '\0'; /* ensure it *is* NUL terminated */
split_escape_and_log(recvbuf, sz);
}
} /* while (!bb_got_signal) */
timestamp_and_log_internal("syslogd exiting");
puts("syslogd exiting");
if (ENABLE_FEATURE_IPC_SYSLOG)
ipcsyslog_cleanup();
kill_myself_with_sig(bb_got_signal);
#undef recvbuf
}
int syslogd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int syslogd_main(int argc UNUSED_PARAM, char **argv)
{
int opts;
char OPTION_DECL;
#if ENABLE_FEATURE_REMOTE_LOG
llist_t *remoteAddrList = NULL;
#endif
INIT_G();
/* No non-option params, -R can occur multiple times */
opt_complementary = "=0" IF_FEATURE_REMOTE_LOG(":R::");
opts = getopt32(argv, OPTION_STR, OPTION_PARAM);
#if ENABLE_FEATURE_REMOTE_LOG
while (remoteAddrList) {
remoteHost_t *rh = xzalloc(sizeof(*rh));
rh->remoteHostname = llist_pop(&remoteAddrList);
rh->remoteFD = -1;
rh->last_dns_resolve = monotonic_sec() - DNS_WAIT_SEC - 1;
llist_add_to(&G.remoteHosts, rh);
}
#endif
#ifdef SYSLOGD_MARK
if (opts & OPT_mark) // -m
G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
#endif
//if (opts & OPT_nofork) // -n
//if (opts & OPT_outfile) // -O
if (opts & OPT_loglevel) // -l
G.logLevel = xatou_range(opt_l, 1, 8);
//if (opts & OPT_small) // -S
#if ENABLE_FEATURE_ROTATE_LOGFILE
if (opts & OPT_filesize) // -s
G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
if (opts & OPT_rotatecnt) // -b
G.logFileRotate = xatou_range(opt_b, 0, 99);
#endif
#if ENABLE_FEATURE_IPC_SYSLOG
if (opt_C) // -Cn
G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
#endif
/* If they have not specified remote logging, then log locally */
if (ENABLE_FEATURE_REMOTE_LOG && !(opts & OPT_remotelog)) // -R
option_mask32 |= OPT_locallog;
#if ENABLE_FEATURE_SYSLOGD_CFG
parse_syslogdcfg(opt_f);
#endif
/* Store away localhost's name before the fork */
G.hostname = safe_gethostname();
*strchrnul(G.hostname, '.') = '\0';
if (!(opts & OPT_nofork)) {
bb_daemonize_or_rexec(DAEMON_CHDIR_ROOT, argv);
}
//umask(0); - why??
write_pidfile("/var/run/syslogd.pid");
do_syslogd();
/* return EXIT_SUCCESS; */
}
/* Clean up. Needed because we are included from syslogd_and_logger.c */
#undef DEBUG
#undef SYSLOGD_MARK
#undef SYSLOGD_WRLOCK
#undef G
#undef GLOBALS
#undef INIT_G
#undef OPTION_STR
#undef OPTION_DECL
#undef OPTION_PARAM
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