diff options
author | Mark Whitley <markw@lineo.com> | 2001-03-13 01:51:50 +0300 |
---|---|---|
committer | Mark Whitley <markw@lineo.com> | 2001-03-13 01:51:50 +0300 |
commit | 6317c4baf79c25d7f77897b064eb4f0b7d9f070e (patch) | |
tree | 5fc8fe65a4903f6224925a72b53a4f46e2b0b1d3 /syslogd.c | |
parent | 4987bbf97924044c88007c45ee2674d97b93ad92 (diff) |
Applied patch from Gennady Feldman to split up syslogd.c into syslogd and
klogd (as it should be).
Diffstat (limited to 'syslogd.c')
-rw-r--r-- | syslogd.c | 318 |
1 files changed, 205 insertions, 113 deletions
@@ -7,6 +7,8 @@ * * Copyright (C) 2000 by Karl M. Hegbloom <karlheg@debian.org> * + * "circular buffer" Copyright (C) 2001 by Gennady Feldman <gfeldman@cachier.com> + * * 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 @@ -40,25 +42,8 @@ #include <sys/un.h> #include <sys/param.h> -#if ! defined __GLIBC__ && ! defined __UCLIBC__ -#include <sys/syscall.h> -#include <linux/unistd.h> -typedef unsigned int socklen_t; - -#ifndef __alpha__ -# define __NR_klogctl __NR_syslog -static inline _syscall3(int, klogctl, int, type, char *, b, int, len); -#else /* __alpha__ */ -#define klogctl syslog -#endif - -#else -# include <sys/klog.h> -#endif #include "busybox.h" - - /* SYSLOG_NAMES defined to pull some extra junk from syslog.h */ #define SYSLOG_NAMES #include <sys/syslog.h> @@ -91,6 +76,184 @@ static int doRemoteLog = FALSE; static int local_logging = FALSE; #endif +/* circular buffer variables/structures */ +#ifdef BB_FEATURE_IPC_SYSLOG + +#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, 2) == -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 /* 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))); @@ -104,6 +267,16 @@ static void message (char *fmt, ...) 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); + vsprintf (b, 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) { @@ -197,6 +370,10 @@ static void quit_signal(int sig) { logMessage(0, "System log daemon exiting."); unlink(lfile); +#ifdef BB_FEATURE_IPC_SYSLOG + ipcsyslog_cleanup(); +#endif + exit(TRUE); } @@ -382,85 +559,6 @@ static void doSyslogd (void) } /* for main loop */ } -#ifdef BB_FEATURE_KLOGD - -static void klogd_signal(int sig) -{ - klogctl(7, NULL, 0); - klogctl(0, 0, 0); - logMessage(0, "Kernel log daemon exiting."); - exit(TRUE); -} - -static void doKlogd (void) __attribute__ ((noreturn)); -static void doKlogd (void) -{ - int priority = LOG_INFO; - char log_buffer[4096]; - int i, n, lastc; - char *start; - - /* Set up sig handlers */ - signal(SIGINT, klogd_signal); - signal(SIGKILL, klogd_signal); - signal(SIGTERM, klogd_signal); - signal(SIGHUP, SIG_IGN); - -#ifdef BB_FEATURE_REMOTE_LOG - if (doRemoteLog == TRUE){ - init_RemoteLog(); - } -#endif - - logMessage(0, "klogd started: " - "BusyBox v" BB_VER " (" BB_BT ")"); - - /* "Open the log. Currently a NOP." */ - klogctl(1, NULL, 0); - - while (1) { - /* Use kernel syscalls */ - memset(log_buffer, '\0', sizeof(log_buffer)); - n = klogctl(2, log_buffer, sizeof(log_buffer)); - if (n < 0) { - char message[80]; - - if (errno == EINTR) - continue; - snprintf(message, 79, "klogd: Error return from sys_sycall: " \ - "%d - %s.\n", errno, strerror(errno)); - logMessage(LOG_SYSLOG | LOG_ERR, message); - exit(1); - } - - /* klogctl buffer parsing modelled after code in dmesg.c */ - start=&log_buffer[0]; - lastc='\0'; - for (i=0; i<n; i++) { - if (lastc == '\0' && log_buffer[i] == '<') { - priority = 0; - i++; - while (isdigit(log_buffer[i])) { - priority = priority*10+(log_buffer[i]-'0'); - i++; - } - if (log_buffer[i] == '>') i++; - start = &log_buffer[i]; - } - if (log_buffer[i] == '\n') { - log_buffer[i] = '\0'; /* zero terminate this message */ - logMessage(LOG_KERN | priority, start); - start = &log_buffer[i+1]; - priority = LOG_INFO; - } - lastc = log_buffer[i]; - } - } - -} - -#endif - static void daemon_init (char **argv, char *dz, void fn (void)) { setsid(); @@ -472,16 +570,13 @@ static void daemon_init (char **argv, char *dz, void fn (void)) extern int syslogd_main(int argc, char **argv) { - int opt, pid, klogd_pid; + int opt, pid; int doFork = TRUE; -#ifdef BB_FEATURE_KLOGD - int startKlogd = TRUE; -#endif char *p; /* do normal option parsing */ - while ((opt = getopt(argc, argv, "m:nKO:R:L")) > 0) { + while ((opt = getopt(argc, argv, "m:nO:R:LC")) > 0) { switch (opt) { case 'm': MarkInterval = atoi(optarg) * 60; @@ -489,11 +584,6 @@ extern int syslogd_main(int argc, char **argv) case 'n': doFork = FALSE; break; -#ifdef BB_FEATURE_KLOGD - case 'K': - startKlogd = FALSE; - break; -#endif case 'O': logFilePath = strdup(optarg); break; @@ -510,6 +600,11 @@ extern int syslogd_main(int argc, char **argv) local_logging = TRUE; break; #endif +#ifdef BB_FEATURE_IPC_SYSLOG + case 'C': + circular_logging = TRUE; + break; +#endif default: show_usage(); } @@ -521,6 +616,7 @@ extern int syslogd_main(int argc, char **argv) local_logging = TRUE; #endif + /* Store away localhost's name before the fork */ gethostname(LocalHostName, sizeof(LocalHostName)); if ((p = strchr(LocalHostName, '.'))) { @@ -529,13 +625,9 @@ extern int syslogd_main(int argc, char **argv) umask(0); -#ifdef BB_FEATURE_KLOGD - /* Start up the klogd process */ - if (startKlogd == TRUE) { - klogd_pid = fork(); - if (klogd_pid == 0) { - daemon_init (argv, "klogd", doKlogd); - } +#ifdef BB_FEATURE_IPC_SYSLOG + if (circular_logging == TRUE ){ + ipcsyslog_init(); } #endif |