syslogd: reduce data/bss usage. Code size is practically the same.
authorDenis Vlasenko <vda.linux@googlemail.com>
Thu, 15 Mar 2007 19:50:46 +0000 (19:50 -0000)
committerDenis Vlasenko <vda.linux@googlemail.com>
Thu, 15 Mar 2007 19:50:46 +0000 (19:50 -0000)
sysklogd/syslogd.c

index 53cb4ba5e9c329864143304908e1374bd40dbd73..8ae75c9743eb269adbffbe025b0c75d1de384574 100644 (file)
 #include <paths.h>
 #include <sys/un.h>
 
-/* SYSLOG_NAMES defined to pull some extra junk from syslog.h */
+/* SYSLOG_NAMES defined to pull some extra junk from syslog.h: */
+/* prioritynames[] and facilitynames[]. uclibc pulls those in _rwdata_! :( */
+
 #define SYSLOG_NAMES
 #include <sys/syslog.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
 
-/* Path for the file where all log messages are written */
-static const char *logFilePath = "/var/log/messages";
-static int logFD = -1;
+// Semaphore operation structures
+struct shbuf_ds {
+       int32_t size;   // size of data written
+       int32_t head;   // start of message list
+       int32_t tail;   // end of message list
+       char data[1];   // data/messages
+};                      // shared memory pointer
+
+struct globals {
+
+       const char *logFilePath;
+       int logFD;
 
-/* This 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) */
+       /* This 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) */
 #ifdef SYSLOGD_MARK
-/* interval between marks in seconds */
-static int markInterval = 20 * 60;
+       /* interval between marks in seconds */
+       int markInterval;
 #endif
 
-/* level of messages to be locally logged */
-static int logLevel = 8;
-
-/* localhost's name */
-static char localHostName[64];
+       /* level of messages to be locally logged */
+       int logLevel;
 
 #if ENABLE_FEATURE_ROTATE_LOGFILE
-/* max size of message file before being rotated */
-static unsigned logFileSize = 200 * 1024;
-/* number of rotated message files */
-static unsigned logFileRotate = 1;
-static unsigned curFileSize;
-static smallint isRegular;
+       /* max size of message file before being rotated */
+       unsigned logFileSize;
+       /* number of rotated message files */
+       unsigned logFileRotate;
+       unsigned curFileSize;
+       smallint isRegular;
 #endif
 
 #if ENABLE_FEATURE_REMOTE_LOG
-#include <netinet/in.h>
-/* udp socket for logging to remote host */
-static int remoteFD = -1;
-static len_and_sockaddr* remoteAddr;
+       /* udp socket for logging to remote host */
+       int remoteFD;
+       len_and_sockaddr* remoteAddr;
+#endif
+
+#if ENABLE_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];
+       struct shbuf_ds *shbuf;
+#endif
+
+       time_t last_log_time;
+       /* localhost's name */
+       char localHostName[64];
+
+}; /* struct globals */
+
+static const struct globals init_globals = {
+       .logFilePath = "/var/log/messages",
+       .logFD = -1,
+#ifdef SYSLOGD_MARK
+       .markInterval = 20 * 60,
+#endif
+       .logLevel = 8,
+#if ENABLE_FEATURE_ROTATE_LOGFILE
+       .logFileSize = 200 * 1024,
+       .logFileRotate = 1,
+#endif
+#if ENABLE_FEATURE_REMOTE_LOG
+       .remoteFD = -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
+       // FIXME: hidden tail with lotsa zeroes is here....
+};
+
+#define G (*ptr_to_globals)
+
 
 /* We are using bb_common_bufsiz1 for buffering: */
 enum { MAX_READ = (BUFSIZ/6) & ~0xf };
@@ -109,7 +169,7 @@ enum {
        USE_FEATURE_ROTATE_LOGFILE(,*opt_b) \
        USE_FEATURE_REMOTE_LOG(    ,*opt_R) \
        USE_FEATURE_IPC_SYSLOG(    ,*opt_C = NULL)
-#define OPTION_PARAM &opt_m, &logFilePath, &opt_l \
+#define OPTION_PARAM &opt_m, &G.logFilePath, &opt_l \
        USE_FEATURE_ROTATE_LOGFILE(,&opt_s) \
        USE_FEATURE_ROTATE_LOGFILE(,&opt_b) \
        USE_FEATURE_REMOTE_LOG(    ,&opt_R) \
@@ -119,68 +179,51 @@ enum {
 /* 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
 
-#include <sys/ipc.h>
-#include <sys/sem.h>
-#include <sys/shm.h>
-
 /* our shared key */
 #define KEY_ID ((long)0x414e4547) /* "GENA" */
 
-// Semaphore operation structures
-static struct shbuf_ds {
-       int32_t size;   // size of data written
-       int32_t head;   // start of message list
-       int32_t tail;   // end of message list
-       char data[1];   // data/messages
-} *shbuf;               // shared memory pointer
-
-static int shmid = -1;   // ipc shared memory id
-static int s_semid = -1; // ipc semaphore id
-static int shm_size = ((CONFIG_FEATURE_IPC_SYSLOG_BUFFER_SIZE)*1024);  // default shm size
-
 static void ipcsyslog_cleanup(void)
 {
-       if (shmid != -1) {
-               shmdt(shbuf);
+       if (G.shmid != -1) {
+               shmdt(G.shbuf);
        }
-       if (shmid != -1) {
-               shmctl(shmid, IPC_RMID, NULL);
+       if (G.shmid != -1) {
+               shmctl(G.shmid, IPC_RMID, NULL);
        }
-       if (s_semid != -1) {
-               semctl(s_semid, 0, IPC_RMID, 0);
+       if (G.s_semid != -1) {
+               semctl(G.s_semid, 0, IPC_RMID, 0);
        }
 }
 
 static void ipcsyslog_init(void)
 {
        if (DEBUG)
-               printf("shmget(%lx, %d,...)\n", KEY_ID, shm_size);
+               printf("shmget(%lx, %d,...)\n", KEY_ID, G.shm_size);
 
-       shmid = shmget(KEY_ID, shm_size, IPC_CREAT | 1023);
-       if (shmid == -1) {
+       G.shmid = shmget(KEY_ID, G.shm_size, IPC_CREAT | 1023);
+       if (G.shmid == -1) {
                bb_perror_msg_and_die("shmget");
        }
 
-       shbuf = shmat(shmid, NULL, 0);
-       if (!shbuf) {
+       G.shbuf = shmat(G.shmid, NULL, 0);
+       if (!G.shbuf) {
                bb_perror_msg_and_die("shmat");
        }
 
-       shbuf->size = shm_size - offsetof(struct shbuf_ds, data);
-       shbuf->head = shbuf->tail = 0;
+       G.shbuf->size = G.shm_size - offsetof(struct shbuf_ds, data);
+       G.shbuf->head = G.shbuf->tail = 0;
 
        // we'll trust the OS to set initial semval to 0 (let's hope)
-       s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
-       if (s_semid == -1) {
+       G.s_semid = semget(KEY_ID, 2, IPC_CREAT | IPC_EXCL | 1023);
+       if (G.s_semid == -1) {
                if (errno == EEXIST) {
-                       s_semid = semget(KEY_ID, 2, 0);
-                       if (s_semid != -1)
+                       G.s_semid = semget(KEY_ID, 2, 0);
+                       if (G.s_semid != -1)
                                return;
                }
                bb_perror_msg_and_die("semget");
@@ -190,14 +233,10 @@ static void ipcsyslog_init(void)
 /* Write message to shared mem buffer */
 static void log_to_shmem(const char *msg, int len)
 {
-       /* Why libc insists on these being rw? */
-       static struct sembuf SMwup[1] = { {1, -1, IPC_NOWAIT} };
-       static struct sembuf SMwdn[3] = { {0, 0}, {1, 0}, {1, +1} };
-
        int old_tail, new_tail;
        char *c;
 
-       if (semop(s_semid, SMwdn, 3) == -1) {
+       if (semop(G.s_semid, G.SMwdn, 3) == -1) {
                bb_perror_msg_and_die("SMwdn");
        }
 
@@ -212,53 +251,53 @@ static void log_to_shmem(const char *msg, int len)
         */
        len++; /* length with NUL included */
  again:
-       old_tail = shbuf->tail;
+       old_tail = G.shbuf->tail;
        new_tail = old_tail + len;
-       if (new_tail < shbuf->size) {
+       if (new_tail < G.shbuf->size) {
                /* No need to move head if shbuf->head <= old_tail,
                 * else... */
-               if (old_tail < shbuf->head && shbuf->head <= new_tail) {
+               if (old_tail < G.shbuf->head && G.shbuf->head <= new_tail) {
                        /* ...need to move head forward */
-                       c = memchr(shbuf->data + new_tail, '\0',
-                                          shbuf->size - new_tail);
+                       c = memchr(G.shbuf->data + new_tail, '\0',
+                                          G.shbuf->size - new_tail);
                        if (!c) /* no NUL ahead of us, wrap around */
-                               c = memchr(shbuf->data, '\0', old_tail);
+                               c = memchr(G.shbuf->data, '\0', old_tail);
                        if (!c) { /* still nothing? point to this msg... */
-                               shbuf->head = old_tail;
+                               G.shbuf->head = old_tail;
                        } else {
                                /* convert pointer to offset + skip NUL */
-                               shbuf->head = c - shbuf->data + 1;
+                               G.shbuf->head = c - G.shbuf->data + 1;
                        }
                }
                /* store message, set new tail */
-               memcpy(shbuf->data + old_tail, msg, len);
-               shbuf->tail = new_tail;
+               memcpy(G.shbuf->data + old_tail, msg, len);
+               G.shbuf->tail = new_tail;
        } else {
                /* we need to break up the message and wrap it around */
                /* k == available buffer space ahead of old tail */
-               int k = shbuf->size - old_tail - 1;
-               if (shbuf->head > old_tail) {
+               int k = G.shbuf->size - old_tail - 1;
+               if (G.shbuf->head > old_tail) {
                        /* we are going to overwrite head, need to
                         * move it out of the way */
-                       c = memchr(shbuf->data, '\0', old_tail);
+                       c = memchr(G.shbuf->data, '\0', old_tail);
                        if (!c) { /* nothing? point to this msg... */
-                               shbuf->head = old_tail;
+                               G.shbuf->head = old_tail;
                        } else { /* convert pointer to offset + skip NUL */
-                               shbuf->head = c - shbuf->data + 1;
+                               G.shbuf->head = c - G.shbuf->data + 1;
                        }
                }
                /* copy what fits to the end of buffer, and repeat */
-               memcpy(shbuf->data + old_tail, msg, k);
+               memcpy(G.shbuf->data + old_tail, msg, k);
                msg += k;
                len -= k;
-               shbuf->tail = 0;
+               G.shbuf->tail = 0;
                goto again;
        }
-       if (semop(s_semid, SMwup, 1) == -1) {
+       if (semop(G.s_semid, G.SMwup, 1) == -1) {
                bb_perror_msg_and_die("SMwup");
        }
        if (DEBUG)
-               printf("head:%d tail:%d\n", shbuf->head, shbuf->tail);
+               printf("head:%d tail:%d\n", G.shbuf->head, G.shbuf->tail);
 }
 #else
 void ipcsyslog_cleanup(void);
@@ -270,29 +309,28 @@ void log_to_shmem(const char *msg);
 /* Print a message to the log file. */
 static void log_locally(char *msg)
 {
-       static time_t last;
        struct flock fl;
        int len = strlen(msg);
 
 #if ENABLE_FEATURE_IPC_SYSLOG
-       if ((option_mask32 & OPT_circularlog) && shbuf) {
+       if ((option_mask32 & OPT_circularlog) && G.shbuf) {
                log_to_shmem(msg, len);
                return;
        }
 #endif
-       if (logFD >= 0) {
+       if (G.logFD >= 0) {
                time_t cur;
                time(&cur);
-               if (last != cur) {
-                       last = cur; /* reopen log file every second */
-                       close(logFD);
+               if (G.last_log_time != cur) {
+                       G.last_log_time = cur; /* reopen log file every second */
+                       close(G.logFD);
                        goto reopen;
                }
        } else {
  reopen:
-               logFD = device_open(logFilePath, O_WRONLY | O_CREAT
+               G.logFD = device_open(G.logFilePath, O_WRONLY | O_CREAT
                                        | O_NOCTTY | O_APPEND | O_NONBLOCK);
-               if (logFD < 0) {
+               if (G.logFD < 0) {
                        /* cannot open logfile? - print to /dev/console then */
                        int fd = device_open(_PATH_CONSOLE, O_WRONLY | O_NOCTTY | O_NONBLOCK);
                        if (fd < 0)
@@ -306,9 +344,9 @@ static void log_locally(char *msg)
                {
                struct stat statf;
 
-               isRegular = (fstat(logFD, &statf) == 0 && (statf.st_mode & S_IFREG));
+               G.isRegular = (fstat(G.logFD, &statf) == 0 && (statf.st_mode & S_IFREG));
                /* bug (mostly harmless): can wrap around if file > 4gb */
-               curFileSize = statf.st_size;
+               G.curFileSize = statf.st_size;
                }
 #endif
        }
@@ -317,36 +355,36 @@ static void log_locally(char *msg)
        fl.l_start = 0;
        fl.l_len = 1;
        fl.l_type = F_WRLCK;
-       fcntl(logFD, F_SETLKW, &fl);
+       fcntl(G.logFD, F_SETLKW, &fl);
 
 #if ENABLE_FEATURE_ROTATE_LOGFILE
-       if (logFileSize && isRegular && curFileSize > logFileSize) {
-               if (logFileRotate) { /* always 0..99 */
-                       int i = strlen(logFilePath) + 3 + 1;
+       if (G.logFileSize && G.isRegular && G.curFileSize > G.logFileSize) {
+               if (G.logFileRotate) { /* always 0..99 */
+                       int i = strlen(G.logFilePath) + 3 + 1;
                        char oldFile[i];
                        char newFile[i];
-                       i = logFileRotate - 1;
+                       i = G.logFileRotate - 1;
                        /* rename: f.8 -> f.9; f.7 -> f.8; ... */
                        while (1) {
-                               sprintf(newFile, "%s.%d", logFilePath, i);
+                               sprintf(newFile, "%s.%d", G.logFilePath, i);
                                if (i == 0) break;
-                               sprintf(oldFile, "%s.%d", logFilePath, --i);
+                               sprintf(oldFile, "%s.%d", G.logFilePath, --i);
                                rename(oldFile, newFile);
                        }
                        /* newFile == "f.0" now */
-                       rename(logFilePath, newFile);
+                       rename(G.logFilePath, newFile);
                        fl.l_type = F_UNLCK;
-                       fcntl(logFD, F_SETLKW, &fl);
-                       close(logFD);
+                       fcntl(G.logFD, F_SETLKW, &fl);
+                       close(G.logFD);
                        goto reopen;
                }
-               ftruncate(logFD, 0);
+               ftruncate(G.logFD, 0);
        }
-       curFileSize +=
+       G.curFileSize +=
 #endif
-                       full_write(logFD, msg, len);
+                       full_write(G.logFD, msg, len);
        fl.l_type = F_UNLCK;
-       fcntl(logFD, F_SETLKW, &fl);
+       fcntl(G.logFD, F_SETLKW, &fl);
 }
 
 static void parse_fac_prio_20(int pri, char *res20)
@@ -397,13 +435,13 @@ static void timestamp_and_log(int pri, char *msg, int len)
 
        /* Log message locally (to file or shared mem) */
        if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
-               if (LOG_PRI(pri) < logLevel) {
+               if (LOG_PRI(pri) < G.logLevel) {
                        if (option_mask32 & OPT_small)
                                sprintf(PRINTBUF, "%s %s\n", timestamp, msg);
                        else {
                                char res[20];
                                parse_fac_prio_20(pri, res);
-                               sprintf(PRINTBUF, "%s %s %s %s\n", timestamp, localHostName, res, msg);
+                               sprintf(PRINTBUF, "%s %s %s %s\n", timestamp, G.localHostName, res, msg);
                        }
                        log_locally(PRINTBUF);
                }
@@ -456,9 +494,9 @@ static void quit_signal(int sig)
 #ifdef SYSLOGD_MARK
 static void do_mark(int sig)
 {
-       if (markInterval) {
+       if (G.markInterval) {
                timestamp_and_log(LOG_SYSLOG | LOG_INFO, (char*)"-- MARK --", 0);
-               alarm(markInterval);
+               alarm(G.markInterval);
        }
 }
 #endif
@@ -482,7 +520,7 @@ static void do_syslogd(void)
 #endif
 #ifdef SYSLOGD_MARK
        signal(SIGALRM, do_mark);
-       alarm(markInterval);
+       alarm(G.markInterval);
 #endif
 
        memset(&sunx, 0, sizeof(sunx));
@@ -541,14 +579,14 @@ static void do_syslogd(void)
 #if ENABLE_FEATURE_REMOTE_LOG
                        /* We are not modifying log messages in any way before send */
                        /* Remote site cannot trust _us_ anyway and need to do validation again */
-                       if (remoteAddr) {
-                               if (-1 == remoteFD) {
-                                       remoteFD = socket(remoteAddr->sa.sa_family, SOCK_DGRAM, 0);
+                       if (G.remoteAddr) {
+                               if (-1 == G.remoteFD) {
+                                       G.remoteFD = socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0);
                                }
-                               if (-1 != remoteFD) {
+                               if (-1 != G.remoteFD) {
                                        /* send message to remote logger, ignore possible error */
-                                       sendto(remoteFD, RECVBUF, i, MSG_DONTWAIT,
-                                               &remoteAddr->sa, remoteAddr->len);
+                                       sendto(G.remoteFD, RECVBUF, i, MSG_DONTWAIT,
+                                               &G.remoteAddr->sa, G.remoteAddr->len);
                                }
                        }
 #endif
@@ -564,33 +602,36 @@ int syslogd_main(int argc, char **argv)
        char OPTION_DECL;
        char *p;
 
+       PTR_TO_GLOBALS = xzalloc(sizeof(G));
+       memcpy(ptr_to_globals, &init_globals, sizeof(init_globals));
+
        /* do normal option parsing */
        opt_complementary = "=0"; /* no non-option params */
        getopt32(argc, argv, OPTION_STR, OPTION_PARAM);
 #ifdef SYSLOGD_MARK
        if (option_mask32 & OPT_mark) // -m
-               markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
+               G.markInterval = xatou_range(opt_m, 0, INT_MAX/60) * 60;
 #endif
        //if (option_mask32 & OPT_nofork) // -n
        //if (option_mask32 & OPT_outfile) // -O
        if (option_mask32 & OPT_loglevel) // -l
-               logLevel = xatou_range(opt_l, 1, 8);
+               G.logLevel = xatou_range(opt_l, 1, 8);
        //if (option_mask32 & OPT_small) // -S
 #if ENABLE_FEATURE_ROTATE_LOGFILE
        if (option_mask32 & OPT_filesize) // -s
-               logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
+               G.logFileSize = xatou_range(opt_s, 0, INT_MAX/1024) * 1024;
        if (option_mask32 & OPT_rotatecnt) // -b
-               logFileRotate = xatou_range(opt_b, 0, 99);
+               G.logFileRotate = xatou_range(opt_b, 0, 99);
 #endif
 #if ENABLE_FEATURE_REMOTE_LOG
        if (option_mask32 & OPT_remotelog) { // -R
-               remoteAddr = xhost2sockaddr(opt_R, 514);
+               G.remoteAddr = xhost2sockaddr(opt_R, 514);
        }
        //if (option_mask32 & OPT_locallog) // -L
 #endif
 #if ENABLE_FEATURE_IPC_SYSLOG
        if (opt_C) // -Cn
-               shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
+               G.shm_size = xatoul_range(opt_C, 4, INT_MAX/1024) * 1024;
 #endif
 
        /* If they have not specified remote logging, then log locally */
@@ -598,8 +639,8 @@ int syslogd_main(int argc, char **argv)
                option_mask32 |= OPT_locallog;
 
        /* Store away localhost's name before the fork */
-       gethostname(localHostName, sizeof(localHostName));
-       p = strchr(localHostName, '.');
+       gethostname(G.localHostName, sizeof(G.localHostName));
+       p = strchr(G.localHostName, '.');
        if (p) {
                *p = '\0';
        }