syslogd: start using bb_common_bufsiz1 instead of stack/malloc

logger: optimize, also use bb_common_bufsiz1 (~40 bytes)
tested to eat arbitrarily-sized input at high speed - ok

2 files changed, 54 insertions, 63 deletions

diff --git a/sysklogd/logger.c b/sysklogd/logger.c
index 8901bd79f..3a4f51575 100644
--- a/sysklogd/logger.c
+++ b/sysklogd/logger.c
@@ -8,13 +8,6 @@
  */
 
 #include "busybox.h"
-#include <stdio.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include <fcntl.h>
-#include <ctype.h>
-#include <string.h>
-#include <stdlib.h>
 
 #if !defined CONFIG_SYSLOGD
 
@@ -93,49 +86,40 @@ int logger_main(int argc, char **argv)
         char *opt_p, *opt_t;
         int pri = LOG_USER | LOG_NOTICE;
         int option = 0;
-        int c, i;
-        char buf[1024], name[128];
+        char name[80];
 
         /* Fill out the name string early (may be overwritten later) */
         bb_getpwuid(name, geteuid(), sizeof(name));
 
         /* Parse any options */
         opt = getopt32(argc, argv, "p:st:", &opt_p, &opt_t);
+        argc -= optind;
+        argv += optind;
         if (opt & 0x1) pri = pencode(opt_p); // -p
         if (opt & 0x2) option |= LOG_PERROR; // -s
         if (opt & 0x4) safe_strncpy(name, opt_t, sizeof(name)); // -t
 
         openlog(name, option, 0);
-        if (optind == argc) {
-                do {
-                        /* read from stdin */
-                        i = 0;
-                        while ((c = getc(stdin)) != EOF && c != '\n' &&
-                                        i < (sizeof(buf)-1)) {
-                                buf[i++] = c;
-                        }
-                        if (i > 0) {
-                                buf[i++] = '\0';
-                                syslog(pri, "%s", buf);
+        if (!argc) {
+                while (fgets(bb_common_bufsiz1, BUFSIZ, stdin)) {
+                        if (bb_common_bufsiz1[0]
+                         && NOT_LONE_CHAR(bb_common_bufsiz1, '\n')
+                        ) {
+                                /* Neither "" nor "\n" */
+                                syslog(pri, "%s", bb_common_bufsiz1);
                         }
-                } while (c != EOF);
+                }
         } else {
                 char *message = NULL;
-                int len = argc - optind; /* for the space between the args
-                                            and  '\0' */
-                opt = len;
-                argv += optind;
-                for (i = 0; i < opt; i++) {
-                        len += strlen(*argv);
+                int len = 1; /* for NUL */
+                int pos = 0;
+                do {
+                        len += strlen(*argv) + 1;
                         message = xrealloc(message, len);
-                        if(!i)
-                                message[0] = '\0';
-                        else
-                                strcat(message, " ");
-                        strcat(message, *argv);
-                        argv++;
-                }
-                syslog(pri, "%s", message);
+                        sprintf(message + pos, " %s", *argv),
+                        pos = len;
+                } while (*++argv);
+                syslog(pri, "%s", message + 1); /* skip leading " " */
         }
 
         closelog();
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index 7edce7a0a..fbb85338a 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -56,13 +56,23 @@ static int remoteFD = -1;
 static struct sockaddr_in remoteAddr;
 #endif
 
-
-/* NB: we may need 2x this amount on stack... */
-enum { MAX_READ = 1024 };
-
-
-/* options */
-/* Correct regardless of combination of CONFIG_xxx */
+/* We are using bb_common_bufsiz1 for buffering: */
+enum { MAX_READ = (BUFSIZ/6) & ~0xf };
+/* We recv into this... (size: MAX_READ ~== BUFSIZ/6) */
+#define RECVBUF  bb_common_bufsiz1
+/* ...then copy here, escaping control chars */
+/* (can grow x2 + 1 max ~== BUFSIZ/3) */
+#define PARSEBUF (bb_common_bufsiz1 + MAX_READ)
+/* ...then sprintf into this, adding timestamp (15 chars),
+ * host (64), fac.prio (20) to the message */
+/* (growth by: 15 + 64 + 20 + delims = ~110) */
+#define PRINTBUF (bb_common_bufsiz1 + 3*MAX_READ + 0x10)
+/* totals: BUFSIZ/6 + BUFSIZ/3 + BUFSIZ/3 = BUFSIZ - BUFSIZ/6
+ * -- we have BUFSIZ/6 extra at the ent of PRINTBUF
+ * which covers needed ~110 extra bytes (and much more) */
+
+
+/* Options */
 enum {
         OPTBIT_mark = 0, // -m
         OPTBIT_nofork, // -n
@@ -175,11 +185,12 @@ static void ipcsyslog_init(void)
         }
 }
 
-/* write message to buffer */
+/* Write message to shared mem buffer */
 static void log_to_shmem(const char *msg, int len)
 {
-        static /*const*/ struct sembuf SMwup[1] = { {1, -1, IPC_NOWAIT} };
-        static /*const*/ struct sembuf SMwdn[3] = { {0, 0}, {1, 0}, {1, +1} };
+        /* 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;
@@ -362,9 +373,9 @@ static void parse_fac_prio_20(int pri, char *res20)
         }
 }
 
-/* len parameter is used only for "is there a timestamp?" check
+/* len parameter is used only for "is there a timestamp?" check.
  * NB: some callers cheat and supply 0 when they know
- * that there is no timestamp, short-cutting the test */
+ * that there is no timestamp, short-cutting the test. */
 static void timestamp_and_log(int pri, char *msg, int len)
 {
         time_t now;
@@ -385,31 +396,29 @@ static void timestamp_and_log(int pri, char *msg, int len)
         if (!ENABLE_FEATURE_REMOTE_LOG || (option_mask32 & OPT_locallog)) {
                 if (LOG_PRI(pri) < logLevel) {
                         if (option_mask32 & OPT_small)
-                                msg = xasprintf("%s %s\n", timestamp, msg);
+                                sprintf(PRINTBUF, "%s %s\n", timestamp, msg);
                         else {
                                 char res[20];
                                 parse_fac_prio_20(pri, res);
-                                msg = xasprintf("%s %s %s %s\n", timestamp, localHostName, res, msg);
+                                sprintf(PRINTBUF, "%s %s %s %s\n", timestamp, localHostName, res, msg);
                         }
-                        log_locally(msg);
-                        free(msg);
+                        log_locally(PRINTBUF);
                 }
         }
 }
 
 static void split_escape_and_log(char *tmpbuf, int len)
 {
-        char line[len * 2 + 1]; /* gcc' cheap alloca */
         char *p = tmpbuf;
 
         tmpbuf += len;
         while (p < tmpbuf) {
                 char c;
-                char *q = line;
+                char *q = PARSEBUF;
                 int pri = (LOG_USER | LOG_NOTICE);
 
                 if (*p == '<') {
-                        /* Parse the magic priority number. */
+                        /* Parse the magic priority number */
                         pri = bb_strtou(p + 1, &p, 10);
                         if (*p == '>') p++;
                         if (pri & ~(LOG_FACMASK | LOG_PRIMASK)) {
@@ -427,8 +436,8 @@ static void split_escape_and_log(char *tmpbuf, int len)
                         *q++ = c;
                 }
                 *q = '\0';
-                /* now log it */
-                timestamp_and_log(pri, line, q - line);
+                /* Now log it */
+                timestamp_and_log(pri, PARSEBUF, q - PARSEBUF);
         }
 }
 
@@ -509,11 +518,10 @@ static void do_syslogd(void)
 
                 if (FD_ISSET(sock_fd, &fds)) {
                         int i;
-#define tmpbuf bb_common_bufsiz1
-                        i = recv(sock_fd, tmpbuf, MAX_READ, 0);
+                        i = recv(sock_fd, RECVBUF, MAX_READ - 1, 0);
                         if (i <= 0)
                                 bb_perror_msg_and_die("UNIX socket error");
-                        /* TODO: maybe supress duplicates? */
+                        /* TODO: maybe suppress duplicates? */
 #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 */
@@ -523,15 +531,14 @@ static void do_syslogd(void)
                                 }
                                 if (-1 != remoteFD) {
                                         /* send message to remote logger, ignore possible error */
-                                        sendto(remoteFD, tmpbuf, i, MSG_DONTWAIT,
+                                        sendto(remoteFD, RECVBUF, i, MSG_DONTWAIT,
                                                 (struct sockaddr *) &remoteAddr,
                                                 sizeof(remoteAddr));
                                 }
                         }
 #endif
-                        tmpbuf[i] = '\0';
-                        split_escape_and_log(tmpbuf, i);
-#undef tmpbuf
+                        RECVBUF[i] = '\0';
+                        split_escape_and_log(RECVBUF, i);
                 } /* FD_ISSET() */
         } /* for */
 }