2004-11-28 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
* log.h: Remove several unused fields from struct zlog. Add comments
for other fields, and add one new field syslog_options that is
used in the new syslog_sigsafe implementation.
* log.c: (syslog_sigsafe) New function to send syslog messages in
an async-signal safe way that can be used inside a signal handler.
(syslog_connect) New function to connect to syslog daemon inside a
signal handler. This function supports only systems where /dev/log
is a unix datagram socket (e.g. not Solaris).
(zlog_signal) Call syslog_sigsafe if syslog logging is enabled.
(zlog_backtrace_sigsafe) Call syslog_sigsafe if syslog logging is
enabled.
(openzlog) Save syslog_options for use in syslog_sigsafe.
(num_append) Fix bug: handle 0 properly.
(hex_append) New function to print a u_long in hex format.
diff --git a/lib/ChangeLog b/lib/ChangeLog
index 74862d2..8dde0eb 100644
--- a/lib/ChangeLog
+++ b/lib/ChangeLog
@@ -1,3 +1,20 @@
+2004-11-28 Andrew J. Schorr <ajschorr@alumni.princeton.edu>
+
+ * log.h: Remove several unused fields from struct zlog. Add comments
+ for other fields, and add one new field syslog_options that is
+ used in the new syslog_sigsafe implementation.
+ * log.c: (syslog_sigsafe) New function to send syslog messages in
+ an async-signal safe way that can be used inside a signal handler.
+ (syslog_connect) New function to connect to syslog daemon inside a
+ signal handler. This function supports only systems where /dev/log
+ is a unix datagram socket (e.g. not Solaris).
+ (zlog_signal) Call syslog_sigsafe if syslog logging is enabled.
+ (zlog_backtrace_sigsafe) Call syslog_sigsafe if syslog logging is
+ enabled.
+ (openzlog) Save syslog_options for use in syslog_sigsafe.
+ (num_append) Fix bug: handle 0 properly.
+ (hex_append) New function to print a u_long in hex format.
+
2004-11-28 Hasso Tepper <hasso at quagga.net>
* command.h: DEFUN_DEPRECATED passes attribute to DEFUN as well.
diff --git a/lib/log.c b/lib/log.c
index 86e3833..d3106cb 100644
--- a/lib/log.c
+++ b/lib/log.c
@@ -24,6 +24,9 @@
#include "log.h"
#include "memory.h"
#include "command.h"
+#ifndef SUNOS_5
+#include <sys/un.h>
+#endif
struct zlog *zlog_default = NULL;
@@ -175,9 +178,11 @@
num_append(char *s, int len, u_long x)
{
char buf[30];
- char *t = &buf[29];
+ char *t;
- *t = '\0';
+ if (!x)
+ return str_append(s,len,"0");
+ *(t = &buf[sizeof(buf)-1]) = '\0';
while (x && (t > buf))
{
*--t = '0'+(x % 10);
@@ -186,14 +191,93 @@
return str_append(s,len,t);
}
-/* Note: the goal here is to use only async-signal-safe functions.
- Needs to be enhanced to support syslog logging. */
+static char *
+hex_append(char *s, int len, u_long x)
+{
+ char buf[30];
+ char *t;
+
+ if (!x)
+ return str_append(s,len,"0");
+ *(t = &buf[sizeof(buf)-1]) = '\0';
+ while (x && (t > buf))
+ {
+ u_int cc = (x % 16);
+ *--t = ((cc < 10) ? ('0'+cc) : ('a'+cc-10));
+ x /= 16;
+ }
+ return str_append(s,len,t);
+}
+
+static int syslog_fd = -1;
+
+/* Needs to be enhanced to support Solaris. */
+static int
+syslog_connect(void)
+{
+#ifdef SUNOS_5
+ return -1;
+#else
+ int fd;
+ char *s;
+ struct sockaddr_un addr;
+
+ if ((fd = socket(AF_UNIX,SOCK_DGRAM,0)) < 0)
+ return -1;
+ addr.sun_family = AF_UNIX;
+#ifdef _PATH_LOG
+#define SYSLOG_SOCKET_PATH _PATH_LOG
+#else
+#define SYSLOG_SOCKET_PATH "/dev/log"
+#endif
+ s = str_append(addr.sun_path,sizeof(addr.sun_path),SYSLOG_SOCKET_PATH);
+#undef SYSLOG_SOCKET_PATH
+ *s = '\0';
+ if (connect(fd,(struct sockaddr *)&addr,sizeof(addr)) < 0)
+ {
+ close(fd);
+ return -1;
+ }
+ return fd;
+#endif
+}
+
+static void
+syslog_sigsafe(int priority, const char *msg, size_t msglen)
+{
+ char buf[sizeof("<1234567890>ripngd[1234567890]: ")+msglen+50];
+ char *s;
+
+ if ((syslog_fd < 0) && ((syslog_fd = syslog_connect()) < 0))
+ return;
+
+#define LOC s,buf+sizeof(buf)-s
+ s = buf;
+ s = str_append(LOC,"<");
+ s = num_append(LOC,priority);
+ s = str_append(LOC,">");
+ /* forget about the timestamp, too difficult in a signal handler */
+ s = str_append(LOC,zlog_default->ident);
+ if (zlog_default->syslog_options & LOG_PID)
+ {
+ s = str_append(LOC,"[");
+ s = num_append(LOC,getpid());
+ s = str_append(LOC,"]");
+ }
+ s = str_append(LOC,": ");
+ s = str_append(LOC,msg);
+ write(syslog_fd,buf,s-buf);
+#undef LOC
+}
+
+/* Note: the goal here is to use only async-signal-safe functions. */
void
zlog_signal(int signo, const char *action)
{
time_t now;
char buf[sizeof("DEFAULT: Received signal S at T; aborting...")+60];
char *s = buf;
+ char *msgstart = buf;
#define LOC s,buf+sizeof(buf)-s
time(&now);
@@ -202,6 +286,7 @@
s = str_append(LOC,zlog_proto_names[zlog_default->protocol]);
*s++ = ':';
*s++ = ' ';
+ msgstart = s;
}
s = str_append(LOC,"Received signal ");
s = num_append(LOC,signo);
@@ -209,7 +294,8 @@
s = num_append(LOC,now);
s = str_append(LOC,"; ");
s = str_append(LOC,action);
- *s++ = '\n';
+ if (s < buf+sizeof(buf))
+ *s++ = '\n';
#define DUMP(FP) write(fileno(FP),buf,s-buf);
if (!zlog_default)
@@ -222,7 +308,11 @@
DUMP(stdout)
if (zlog_default->flags & ZLOG_STDERR)
DUMP(stderr)
- /* Is there a signal-safe way to send a syslog message? */
+ if (zlog_default->flags & ZLOG_SYSLOG)
+ {
+ *--s = '\0';
+ syslog_sigsafe(LOG_ERR|zlog_default->facility,msgstart,s-msgstart);
+ }
}
#undef DUMP
@@ -269,7 +359,23 @@
DUMP(stdout)
if (zlog_default->flags & ZLOG_STDERR)
DUMP(stderr)
- /* Is there a signal-safe way to send a syslog message? */
+ if (zlog_default->flags & ZLOG_SYSLOG)
+ {
+ int i;
+ *--s = '\0';
+ syslog_sigsafe(priority|zlog_default->facility,buf,s-buf);
+ /* Just print the function addresses. */
+ for (i = 0; i < size; i++)
+ {
+ s = buf;
+ s = str_append(LOC,"[bt ");
+ s = num_append(LOC,i);
+ s = str_append(LOC,"] 0x");
+ s = hex_append(LOC,(u_long)(array[i]));
+ *s = '\0';
+ syslog_sigsafe(priority|zlog_default->facility,buf,s-buf);
+ }
+ }
}
#undef DUMP
#undef LOC
@@ -391,6 +497,7 @@
zl->facility = syslog_facility;
zl->maskpri = LOG_DEBUG;
zl->record_priority = 0;
+ zl->syslog_options = syslog_flags;
openlog (progname, syslog_flags, zl->facility);
diff --git a/lib/log.h b/lib/log.h
index 17b24cd..54cc2a6 100644
--- a/lib/log.h
+++ b/lib/log.h
@@ -46,18 +46,16 @@
struct zlog
{
- const char *ident;
+ const char *ident; /* daemon name (first arg to openlog) */
zlog_proto_t protocol;
- int flags;
+ int flags; /* mask indicating which destinations to log to */
FILE *fp;
char *filename;
- int syslog;
- int stat;
- int connected;
- int maskpri; /* as per syslog setlogmask */
- int priority; /* as per syslog priority */
+ int maskpri; /* discard messages with priority > maskpri */
int facility; /* as per syslog facility */
- int record_priority;
+ int record_priority; /* should messages logged through stdio include the
+ priority of the message? */
+ int syslog_options; /* 2nd arg to openlog */
};
/* Message structure. */