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-rw-r--r--sysklogd/syslogd.c318
1 files changed, 205 insertions, 113 deletions
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index 1276201..a7f982a 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -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