MEDIUM: log: use a separate buffer for the header and for the message

Make sendmsg() use two vectors, one for the message header that is updated
by update_log_hdr() and one for the message buffer.

diff --git a/include/proto/log.h b/include/proto/log.h
index 0967ae8bf0fd394dfb8484b6f53603ecf01697a3..14dfc5bcd40c143a27053e1a9c252ab7b2d80b90 100644 (file)
--- a/include/proto/log.h
+++ b/include/proto/log.h
@@ -39,6 +39,7 @@ extern char *log_format;
 extern char default_tcp_log_format[];
 extern char default_http_log_format[];
 extern char clf_http_log_format[];
+extern char *logheader;
 extern char *logline;
 
 

diff --git a/include/types/log.h b/include/types/log.h
index f6f6e99a62a656a3e0d84877cfc494fcf8ce7437..6707aa6b5640c727e207cc0c58c96be748183b4c 100644 (file)
--- a/include/types/log.h
+++ b/include/types/log.h
@@ -30,7 +30,7 @@
 
 #define NB_LOG_FACILITIES       24
 #define NB_LOG_LEVELS           8
-#define NB_MSG_IOVEC_ELEMENTS   1
+#define NB_MSG_IOVEC_ELEMENTS   2
 #define SYSLOG_PORT             514
 #define UNIQUEID_LEN            128
 

diff --git a/src/cfgparse.c b/src/cfgparse.c
index b40588fb6ed75df0e99e7012fdb7f5246cff8594..39ee3598808b63d231ecd02baeb95f14c01188c8 100644 (file)
--- a/src/cfgparse.c
+++ b/src/cfgparse.c
@@ -1571,6 +1571,7 @@ int cfg_parse_global(const char *file, int linenum, char **args, int kwm)
 
                if (logsrv->maxlen > global.max_syslog_len) {
                        global.max_syslog_len = logsrv->maxlen;
+                       logheader = realloc(logheader, global.max_syslog_len + 1);
                        logline = realloc(logline, global.max_syslog_len + 1);
                }
 
@@ -5853,6 +5854,7 @@ stats_error_parsing:
 
                        if (logsrv->maxlen > global.max_syslog_len) {
                                global.max_syslog_len = logsrv->maxlen;
+                               logheader = realloc(logheader, global.max_syslog_len + 1);
                                logline = realloc(logline, global.max_syslog_len + 1);
                        }
 

diff --git a/src/log.c b/src/log.c
index 8a7e5f4823b031e27daf184a40ded6124776cda2..3724dd47e22653a34f946f56ccdf48bf2a47fbcd 100644 (file)
--- a/src/log.c
+++ b/src/log.c
@@ -151,8 +151,14 @@ char clf_http_log_format[] = "%{+Q}o %{-Q}ci - - [%T] %r %ST %B \"\" \"\" %cp %m
 char default_tcp_log_format[] = "%ci:%cp [%t] %ft %b/%s %Tw/%Tc/%Tt %B %ts %ac/%fc/%bc/%sc/%rc %sq/%bq";
 char *log_format = NULL;
 
-/* This is a global syslog line, common to all outgoing messages. It begins
- * with the syslog tag and the date that are updated by update_log_hdr().
+/* This is a global syslog header, common to all outgoing messages. It
+ * begins with the syslog tag and the date that are updated by
+ * update_log_hdr().
+ */
+char *logheader = NULL;
+
+/* This is a global syslog message buffer, common to all outgoing
+ * messages. It contains only the data part.
  */
 char *logline = NULL;
 
@@ -734,7 +740,7 @@ char *lf_port(char *dst, struct sockaddr *sockaddr, size_t size, struct logforma
        return ret;
 }
 
-/* Re-generate the syslog header at the beginning of logline once a second and
+/* Re-generate the syslog header at the beginning of logheader once a second and
  * return the pointer to the first character after the header.
  */
 static char *update_log_hdr(const char *log_tag)
@@ -751,7 +757,7 @@ static char *update_log_hdr(const char *log_tag)
                tvsec = date.tv_sec;
                get_localtime(tvsec, &tm);
 
-               hdr_len = snprintf(logline, global.max_syslog_len,
+               hdr_len = snprintf(logheader, global.max_syslog_len,
                                   "<<<<>%s %2d %02d:%02d:%02d %s",
                                   monthname[tm.tm_mon],
                                   tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
@@ -763,36 +769,32 @@ static char *update_log_hdr(const char *log_tag)
                if (hdr_len < 0 || hdr_len > global.max_syslog_len)
                        hdr_len = global.max_syslog_len;
 
-               dataptr = logline + hdr_len;
+               dataptr = logheader + hdr_len;
        }
 
        dataptr[0] = 0; // ensure we get rid of any previous attempt
 
-       tag_len = snprintf(dataptr, logline + global.max_syslog_len - dataptr, "%s[%d]: ", log_tag, pid);
-       if (tag_len < 0 || tag_len > logline + global.max_syslog_len - dataptr)
-               tag_len = logline + global.max_syslog_len - dataptr;
+       tag_len = snprintf(dataptr, logheader + global.max_syslog_len - dataptr, "%s[%d]: ", log_tag, pid);
+       if (tag_len < 0 || tag_len > logheader + global.max_syslog_len - dataptr)
+               tag_len = logheader + global.max_syslog_len - dataptr;
 
        return dataptr + tag_len;
 }
 
 /*
- * This function adds a header to the message and sends the syslog message
- * using a printf format string. It expects an LF-terminated message.
+ * This function sends the syslog message using a printf format string. It
+ * expects an LF-terminated message.
  */
 void send_log(struct proxy *p, int level, const char *format, ...)
 {
        va_list argp;
-       char *dataptr;
        int  data_len;
 
        if (level < 0 || format == NULL || logline == NULL)
                return;
 
-       dataptr = update_log_hdr(p && p->log_tag ? p->log_tag : global.log_tag); /* update log header and skip it */
-       data_len = dataptr - logline;
-
        va_start(argp, format);
-       data_len += vsnprintf(dataptr, logline + global.max_syslog_len - dataptr, format, argp);
+       data_len = vsnprintf(logline, global.max_syslog_len, format, argp);
        if (data_len < 0 || data_len > global.max_syslog_len)
                data_len = global.max_syslog_len;
        va_end(argp);
@@ -803,7 +805,7 @@ void send_log(struct proxy *p, int level, const char *format, ...)
 /*
  * This function sends a syslog message.
  * It doesn't care about errors nor does it report them.
- * It overrides the last byte (message[size-1]) with an LF character.
+ * It overrides the last byte of the vector with an LF character.
  */
 void __send_log(struct proxy *p, int level, char *message, size_t size)
 {
@@ -819,7 +821,10 @@ void __send_log(struct proxy *p, int level, char *message, size_t size)
        struct list *logsrvs = NULL;
        struct logsrv *tmp = NULL;
        int nblogger;
+       char *log_tag = global.log_tag;
        char *log_ptr;
+       char *hdr_ptr;
+       size_t hdr_size;
 
        dataptr = message;
 
@@ -831,11 +836,17 @@ void __send_log(struct proxy *p, int level, char *message, size_t size)
                if (!LIST_ISEMPTY(&p->logsrvs)) {
                        logsrvs = &p->logsrvs;
                }
+               if (p->log_tag) {
+                       log_tag = p->log_tag;
+               }
        }
 
        if (!logsrvs)
                return;
 
+       hdr_ptr = update_log_hdr(log_tag);
+       hdr_size = hdr_ptr - logheader;
+
        /* Send log messages to syslog server. */
        nblogger = 0;
        list_for_each_entry(tmp, logsrvs, list) {
@@ -843,7 +854,8 @@ void __send_log(struct proxy *p, int level, char *message, size_t size)
                int *plogfd = logsrv->addr.ss_family == AF_UNIX ?
                        &logfdunix : &logfdinet;
                int sent;
-               int max;
+               int hdr_max = 0;
+               int max = 1;
                char backup;
 
                nblogger++;
@@ -875,34 +887,46 @@ void __send_log(struct proxy *p, int level, char *message, size_t size)
                 * and we change the pointer to the header accordingly.
                 */
                fac_level = (logsrv->facility << 3) + MAX(level, logsrv->minlvl);
-               log_ptr = dataptr + 3; /* last digit of the log level */
+               hdr_ptr = logheader + 3; /* last digit of the log level */
                do {
-                       *log_ptr = '0' + fac_level % 10;
+                       *hdr_ptr = '0' + fac_level % 10;
                        fac_level /= 10;
-                       log_ptr--;
-               } while (fac_level && log_ptr > dataptr);
-               *log_ptr = '<';
+                       hdr_ptr--;
+               } while (fac_level && hdr_ptr > logheader);
+               *hdr_ptr = '<';
+
+               log_ptr = dataptr;
 
-               max = size - (log_ptr - dataptr);
-               if (max > logsrv->maxlen)
-                       max = logsrv->maxlen;
+               hdr_max = hdr_size - (hdr_ptr - logheader);
 
+               if (unlikely(hdr_size >= logsrv->maxlen)) {
+                       hdr_max = MIN(hdr_max, logsrv->maxlen) - 1;
+                       goto send;
+               }
+
+               max = MIN(size, logsrv->maxlen - hdr_max);
+
+               log_ptr += max - 1;
+
+send:
                /* insert a \n at the end of the message, but save what was
                 * there first because we could have different max lengths
                 * for different log targets.
                 */
-               backup = log_ptr[max - 1];
-               log_ptr[max - 1] = '\n';
+               backup = *log_ptr;
+               *log_ptr = '\n';
 
-               iovec[0].iov_base = log_ptr;
-               iovec[0].iov_len = max;
+               iovec[0].iov_base = hdr_ptr;
+               iovec[0].iov_len = hdr_max;
+               iovec[1].iov_base = dataptr;
+               iovec[1].iov_len = max;
 
                msghdr.msg_name = (struct sockaddr *)&logsrv->addr;
                msghdr.msg_namelen = get_addr_len(&logsrv->addr);
 
                sent = sendmsg(*plogfd, &msghdr, MSG_DONTWAIT | MSG_NOSIGNAL);
 
-               log_ptr[max - 1] = backup;
+               *log_ptr = backup;
 
                if (sent < 0) {
                        Alert("sendmsg logger #%d failed: %s (errno=%d)\n",
@@ -1822,7 +1846,6 @@ out:
 void strm_log(struct stream *s)
 {
        struct session *sess = s->sess;
-       char *tmplog;
        int size, err, level;
 
        /* if we don't want to log normal traffic, return now */
@@ -1857,9 +1880,7 @@ void strm_log(struct stream *s)
                        build_logline(s, s->unique_id, UNIQUEID_LEN, &sess->fe->format_unique_id);
        }
 
-       tmplog = update_log_hdr(sess->fe->log_tag ? sess->fe->log_tag : global.log_tag);
-       size = tmplog - logline;
-       size += build_logline(s, tmplog, global.max_syslog_len - size, &sess->fe->logformat);
+       size = build_logline(s, logline, global.max_syslog_len, &sess->fe->logformat);
        if (size > 0) {
                sess->fe->log_count++;
                __send_log(sess->fe, level, logline, size + 1);