diff options
Diffstat (limited to 'syslogd.c')
| -rw-r--r-- | syslogd.c | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/syslogd.c b/syslogd.c new file mode 100644 index 000000000..784337b0b --- /dev/null +++ b/syslogd.c @@ -0,0 +1,638 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini syslogd implementation for busybox + * + * Copyright (C) 1999,2000 by Lineo, inc. and Erik Andersen + * Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.org> + * + * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org> + * + * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@cachier.com> + * + * Maintainer: Gennady Feldman <gena01@cachier.com> as of Mar 12, 2001 + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + * + */ + +#include <stdio.h> +#include <stdlib.h> +#include <ctype.h> +#include <errno.h> +#include <fcntl.h> +#include <netdb.h> +#include <paths.h> +#include <signal.h> +#include <stdarg.h> +#include <time.h> +#include <string.h> +#include <unistd.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <sys/un.h> +#include <sys/param.h> + +#include "busybox.h" + +/* SYSLOG_NAMES defined to pull some extra junk from syslog.h */ +#define SYSLOG_NAMES +#include <sys/syslog.h> +#include <sys/uio.h> + +/* Path for the file where all log messages are written */ +#define __LOG_FILE "/var/log/messages" + +/* Path to the unix socket */ +static char lfile[MAXPATHLEN]; + +static char *logFilePath = __LOG_FILE; + +/* interval between marks in seconds */ +static int MarkInterval = 20 * 60; + +/* localhost's name */ +static char LocalHostName[64]; + +#ifdef BB_FEATURE_REMOTE_LOG +#include <netinet/in.h> +/* udp socket for logging to remote host */ +static int remotefd = -1; +/* where do we log? */ +static char *RemoteHost; +/* what port to log to? */ +static int RemotePort = 514; +/* To remote log or not to remote log, that is the question. */ +static int doRemoteLog = FALSE; +static int local_logging = FALSE; +#endif + + +#define MAXLINE 1024 /* maximum line length */ + + +/* circular buffer variables/structures */ +#ifdef BB_FEATURE_IPC_SYSLOG +#if __GNU_LIBRARY__ < 5 +#error Sorry. Looks like you are using libc5. +#error libc5 shm support isnt good enough. +#error Please disable BB_FEATURE_IPC_SYSLOG +#endif + +#include <sys/ipc.h> +#include <sys/sem.h> +#include <sys/shm.h> + +/* our shared key */ +static const long KEY_ID = 0x414e4547; /*"GENA"*/ + +// Semaphore operation structures +static struct shbuf_ds { + int size; // size of data written + int head; // start of message list + int tail; // end of message list + char data[1]; // data/messages +} *buf = NULL; // shared memory pointer + +static struct sembuf SMwup[1] = {{1, -1, IPC_NOWAIT}}; // set SMwup +static struct sembuf SMwdn[3] = {{0, 0}, {1, 0}, {1, +1}}; // set SMwdn + +static int shmid = -1; // ipc shared memory id +static int s_semid = -1; // ipc semaphore id +int data_size = 16000; // data size +int shm_size = 16000 + sizeof(*buf); // our buffer size +static int circular_logging = FALSE; + +/* + * sem_up - up()'s a semaphore. + */ +static inline void sem_up(int semid) +{ + if ( semop(semid, SMwup, 1) == -1 ) + perror_msg_and_die("semop[SMwup]"); +} + +/* + * sem_down - down()'s a semaphore + */ +static inline void sem_down(int semid) +{ + if ( semop(semid, SMwdn, 3) == -1 ) + perror_msg_and_die("semop[SMwdn]"); +} + + +void ipcsyslog_cleanup(void){ + printf("Exiting Syslogd!\n"); + if (shmid != -1) + shmdt(buf); + + if (shmid != -1) + shmctl(shmid, IPC_RMID, NULL); + if (s_semid != -1) + semctl(s_semid, 0, IPC_RMID, 0); +} + +void ipcsyslog_init(void){ + if (buf == NULL){ + if ((shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023)) == -1) + perror_msg_and_die("shmget"); + + + if ((buf = shmat(shmid, NULL, 0)) == NULL) + perror_msg_and_die("shmat"); + + + buf->size=data_size; + buf->head=buf->tail=0; + + // we'll trust the OS to set initial semval to 0 (let's hope) + if ((s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023)) == -1){ + if (errno == EEXIST){ + if ((s_semid = semget(KEY_ID, 2, 0)) == -1) + perror_msg_and_die("semget"); + }else + perror_msg_and_die("semget"); + } + }else{ + printf("Buffer already allocated just grab the semaphore?"); + } +} + +/* write message to buffer */ +void circ_message(const char *msg){ + int l=strlen(msg)+1; /* count the whole message w/ '\0' included */ + + sem_down(s_semid); + + /* + * Circular Buffer Algorithm: + * -------------------------- + * + * Start-off w/ empty buffer of specific size SHM_SIZ + * Start filling it up w/ messages. I use '\0' as separator to break up messages. + * This is also very handy since we can do printf on message. + * + * Once the buffer is full we need to get rid of the first message in buffer and + * insert the new message. (Note: if the message being added is >1 message then + * we will need to "remove" >1 old message from the buffer). The way this is done + * is the following: + * When we reach the end of the buffer we set a mark and start from the beginning. + * Now what about the beginning and end of the buffer? Well we have the "head" + * index/pointer which is the starting point for the messages and we have "tail" + * index/pointer which is the ending point for the messages. When we "display" the + * messages we start from the beginning and continue until we reach "tail". If we + * reach end of buffer, then we just start from the beginning (offset 0). "head" and + * "tail" are actually offsets from the beginning of the buffer. + * + * Note: This algorithm uses Linux IPC mechanism w/ shared memory and semaphores to provide + * a threasafe way of handling shared memory operations. + */ + if ( (buf->tail + l) < buf->size ){ + /* before we append the message we need to check the HEAD so that we won't + overwrite any of the message that we still need and adjust HEAD to point + to the next message! */ + if ( buf->tail < buf->head){ + if ( (buf->tail + l) >= buf->head ){ + /* we need to move the HEAD to point to the next message + * Theoretically we have enough room to add the whole message to the + * buffer, because of the first outer IF statement, so we don't have + * to worry about overflows here! + */ + int k= buf->tail + l - buf->head; /* we need to know how many bytes + we are overwriting to make + enough room */ + char *c=memchr(buf->data+buf->head + k,'\0',buf->size - (buf->head + k)); + if (c != NULL) {/* do a sanity check just in case! */ + buf->head = c - buf->data + 1; /* we need to convert pointer to + offset + skip the '\0' since + we need to point to the beginning + of the next message */ + /* Note: HEAD is only used to "retrieve" messages, it's not used + when writing messages into our buffer */ + }else{ /* show an error message to know we messed up? */ + printf("Weird! Can't find the terminator token??? \n"); + buf->head=0; + } + } + } /* in other cases no overflows have been done yet, so we don't care! */ + + /* we should be ok to append the message now */ + strncpy(buf->data + buf->tail,msg,l); /* append our message */ + buf->tail+=l; /* count full message w/ '\0' terminating char */ + }else{ + /* we need to break up the message and "circle" it around */ + char *c; + int k=buf->tail + l - buf->size; /* count # of bytes we don't fit */ + + /* We need to move HEAD! This is always the case since we are going + * to "circle" the message. + */ + c=memchr(buf->data + k ,'\0', buf->size - k); + + if (c != NULL) /* if we don't have '\0'??? weird!!! */{ + /* move head pointer*/ + buf->head=c-buf->data+1; + + /* now write the first part of the message */ + strncpy(buf->data + buf->tail, msg, l - k - 1); + + /* ALWAYS terminate end of buffer w/ '\0' */ + buf->data[buf->size-1]='\0'; + + /* now write out the rest of the string to the beginning of the buffer */ + strcpy(buf->data, &msg[l-k-1]); + + /* we need to place the TAIL at the end of the message */ + buf->tail = k + 1; + }else{ + printf("Weird! Can't find the terminator token from the beginning??? \n"); + buf->head = buf->tail = 0; /* reset buffer, since it's probably corrupted */ + } + + } + sem_up(s_semid); +} +#endif /* BB_FEATURE_IPC_SYSLOG */ + +/* Note: There is also a function called "message()" in init.c */ +/* Print a message to the log file. */ +static void message (char *fmt, ...) __attribute__ ((format (printf, 1, 2))); +static void message (char *fmt, ...) +{ + int fd; + struct flock fl; + va_list arguments; + + fl.l_whence = SEEK_SET; + fl.l_start = 0; + fl.l_len = 1; + +#ifdef BB_FEATURE_IPC_SYSLOG + if ((circular_logging == TRUE) && (buf != NULL)){ + char b[1024]; + va_start (arguments, fmt); + vsnprintf (b, sizeof(b)-1, fmt, arguments); + va_end (arguments); + circ_message(b); + + }else +#endif + if ((fd = device_open (logFilePath, + O_WRONLY | O_CREAT | O_NOCTTY | O_APPEND | + O_NONBLOCK)) >= 0) { + fl.l_type = F_WRLCK; + fcntl (fd, F_SETLKW, &fl); + va_start (arguments, fmt); + vdprintf (fd, fmt, arguments); + va_end (arguments); + fl.l_type = F_UNLCK; + fcntl (fd, F_SETLKW, &fl); + close (fd); + } else { + /* Always send console messages to /dev/console so people will see them. */ + if ((fd = device_open (_PATH_CONSOLE, + O_WRONLY | O_NOCTTY | O_NONBLOCK)) >= 0) { + va_start (arguments, fmt); + vdprintf (fd, fmt, arguments); + va_end (arguments); + close (fd); + } else { + fprintf (stderr, "Bummer, can't print: "); + va_start (arguments, fmt); + vfprintf (stderr, fmt, arguments); + fflush (stderr); + va_end (arguments); + } + } +} + +static void logMessage (int pri, char *msg) +{ + time_t now; + char *timestamp; + static char res[20] = ""; + CODE *c_pri, *c_fac; + + if (pri != 0) { + for (c_fac = facilitynames; + c_fac->c_name && !(c_fac->c_val == LOG_FAC(pri) << 3); c_fac++); + for (c_pri = prioritynames; + c_pri->c_name && !(c_pri->c_val == LOG_PRI(pri)); c_pri++); + if (c_fac->c_name == NULL || c_pri->c_name == NULL) + snprintf(res, sizeof(res), "<%d>", pri); + else + snprintf(res, sizeof(res), "%s.%s", c_fac->c_name, c_pri->c_name); + } + + if (strlen(msg) < 16 || msg[3] != ' ' || msg[6] != ' ' || + msg[9] != ':' || msg[12] != ':' || msg[15] != ' ') { + time(&now); + timestamp = ctime(&now) + 4; + timestamp[15] = '\0'; + } else { + timestamp = msg; + timestamp[15] = '\0'; + msg += 16; + } + + /* todo: supress duplicates */ + +#ifdef BB_FEATURE_REMOTE_LOG + /* send message to remote logger */ + if ( -1 != remotefd){ +static const int IOV_COUNT = 2; + struct iovec iov[IOV_COUNT]; + struct iovec *v = iov; + + memset(&res, 0, sizeof(res)); + snprintf(res, sizeof(res), "<%d>", pri); + v->iov_base = res ; + v->iov_len = strlen(res); + v++; + + v->iov_base = msg; + v->iov_len = strlen(msg); +writev_retry: + if ( -1 == writev(remotefd,iov, IOV_COUNT)){ + if (errno == EINTR) goto writev_retry; + error_msg_and_die("cannot write to remote file handle on" + "%s:%d",RemoteHost,RemotePort); + } + } + if (local_logging == TRUE) +#endif + /* now spew out the message to wherever it is supposed to go */ + message("%s %s %s %s\n", timestamp, LocalHostName, res, msg); + + +} + +static void quit_signal(int sig) +{ + logMessage(LOG_SYSLOG | LOG_INFO, "System log daemon exiting."); + unlink(lfile); +#ifdef BB_FEATURE_IPC_SYSLOG + ipcsyslog_cleanup(); +#endif + + exit(TRUE); +} + +static void domark(int sig) +{ + if (MarkInterval > 0) { + logMessage(LOG_SYSLOG | LOG_INFO, "-- MARK --"); + alarm(MarkInterval); + } +} + +/* This must be a #define, since when DODEBUG and BUFFERS_GO_IN_BSS are + * enabled, we otherwise get a "storage size isn't constant error. */ +static int serveConnection (char* tmpbuf, int n_read) +{ + char *p = tmpbuf; + + while (p < tmpbuf + n_read) { + + int pri = (LOG_USER | LOG_NOTICE); + int num_lt = 0; + char line[ MAXLINE + 1 ]; + unsigned char c; + + char *q = line; + + while ( (c = *p) && q < &line[ sizeof (line) - 1 ]) { + if (c == '<' && num_lt == 0) { + /* Parse the magic priority number. */ + num_lt++; + pri = 0; + while (isdigit (*(++p))) { + pri = 10 * pri + (*p - '0'); + } + if (pri & ~(LOG_FACMASK | LOG_PRIMASK)){ + pri = (LOG_USER | LOG_NOTICE); + } + } else if (c == '\n') { + *q++ = ' '; + } else if (iscntrl (c) && (c < 0177)) { + *q++ = '^'; + *q++ = c ^ 0100; + } else { + *q++ = c; + } + p++; + } + *q = '\0'; + p++; + /* Now log it */ + logMessage (pri, line); + } + return n_read; +} + + +#ifdef BB_FEATURE_REMOTE_LOG +static void init_RemoteLog (void) +{ + + struct sockaddr_in remoteaddr; + struct hostent *hostinfo; + int len = sizeof(remoteaddr); + + memset(&remoteaddr, 0, len); + + remotefd = socket(AF_INET, SOCK_DGRAM, 0); + + if (remotefd < 0) { + error_msg_and_die("cannot create socket"); + } + + hostinfo = xgethostbyname(RemoteHost); + + remoteaddr.sin_family = AF_INET; + remoteaddr.sin_addr = *(struct in_addr *) *hostinfo->h_addr_list; + remoteaddr.sin_port = htons(RemotePort); + + /* + Since we are using UDP sockets, connect just sets the default host and port + for future operations + */ + if ( 0 != (connect(remotefd, (struct sockaddr *) &remoteaddr, len))){ + error_msg_and_die("cannot connect to remote host %s:%d", RemoteHost, RemotePort); + } + +} +#endif + +static void doSyslogd (void) __attribute__ ((noreturn)); +static void doSyslogd (void) +{ + struct sockaddr_un sunx; + socklen_t addrLength; + + int sock_fd; + fd_set fds; + + /* Set up signal handlers. */ + signal (SIGINT, quit_signal); + signal (SIGTERM, quit_signal); + signal (SIGQUIT, quit_signal); + signal (SIGHUP, SIG_IGN); + signal (SIGCHLD, SIG_IGN); +#ifdef SIGCLD + signal (SIGCLD, SIG_IGN); +#endif + signal (SIGALRM, domark); + alarm (MarkInterval); + + /* Create the syslog file so realpath() can work. */ + if (realpath (_PATH_LOG, lfile) != NULL) + unlink (lfile); + + memset (&sunx, 0, sizeof (sunx)); + sunx.sun_family = AF_UNIX; + strncpy (sunx.sun_path, lfile, sizeof (sunx.sun_path)); + if ((sock_fd = socket (AF_UNIX, SOCK_DGRAM, 0)) < 0) + perror_msg_and_die ("Couldn't get file descriptor for socket " _PATH_LOG); + + addrLength = sizeof (sunx.sun_family) + strlen (sunx.sun_path); + if (bind(sock_fd, (struct sockaddr *) &sunx, addrLength) < 0) + perror_msg_and_die ("Could not connect to socket " _PATH_LOG); + + if (chmod (lfile, 0666) < 0) + perror_msg_and_die ("Could not set permission on " _PATH_LOG); + + +#ifdef BB_FEATURE_IPC_SYSLOG + if (circular_logging == TRUE ){ + ipcsyslog_init(); + } +#endif + +#ifdef BB_FEATURE_REMOTE_LOG + if (doRemoteLog == TRUE){ + init_RemoteLog(); + } +#endif + + logMessage (LOG_SYSLOG | LOG_INFO, "syslogd started: " BB_BANNER); + + for (;;) { + + FD_ZERO (&fds); + FD_SET (sock_fd, &fds); + + if (select (sock_fd+1, &fds, NULL, NULL, NULL) < 0) { + if (errno == EINTR) { + /* alarm may have happened. */ + continue; + } + perror_msg_and_die ("select error"); + } + + if (FD_ISSET (sock_fd, &fds)) { + int i; + RESERVE_BB_BUFFER(tmpbuf, MAXLINE + 1); + + memset(tmpbuf, '\0', MAXLINE+1); + if ( (i = recv(sock_fd, tmpbuf, MAXLINE, 0)) > 0) { + serveConnection(tmpbuf, i); + } else { + perror_msg_and_die ("UNIX socket error"); + } + RELEASE_BB_BUFFER (tmpbuf); + }/* FD_ISSET() */ + } /* for main loop */ +} + +extern int syslogd_main(int argc, char **argv) +{ + int opt; +#if ! defined(__uClinux__) + int doFork = TRUE; +#endif + + char *p; + + /* do normal option parsing */ + while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) { + switch (opt) { + case 'm': + MarkInterval = atoi(optarg) * 60; + break; +#if ! defined(__uClinux__) + case 'n': + doFork = FALSE; + break; +#endif + case 'O': + logFilePath = xstrdup(optarg); + break; +#ifdef BB_FEATURE_REMOTE_LOG + case 'R': + RemoteHost = xstrdup(optarg); + if ( (p = strchr(RemoteHost, ':'))){ + RemotePort = atoi(p+1); + *p = '\0'; + } + doRemoteLog = TRUE; + break; + case 'L': + local_logging = TRUE; + break; +#endif +#ifdef BB_FEATURE_IPC_SYSLOG + case 'C': + circular_logging = TRUE; + break; +#endif + default: + show_usage(); + } + } + +#ifdef BB_FEATURE_REMOTE_LOG + /* If they have not specified remote logging, then log locally */ + if (doRemoteLog == FALSE) + local_logging = TRUE; +#endif + + + /* Store away localhost's name before the fork */ + gethostname(LocalHostName, sizeof(LocalHostName)); + if ((p = strchr(LocalHostName, '.'))) { + *p++ = '\0'; + } + + umask(0); + +#if ! defined(__uClinux__) + if (doFork == TRUE) { + if (daemon(0, 1) < 0) + perror_msg_and_die("daemon"); + } +#endif + doSyslogd(); + + return EXIT_SUCCESS; +} + +/* +Local Variables +c-file-style: "linux" +c-basic-offset: 4 +tab-width: 4 +End: +*/ |