diff options
Diffstat (limited to 'main/musl/0003-handle-loss-of-syslog-socket-connection.patch')
| -rw-r--r-- | main/musl/0003-handle-loss-of-syslog-socket-connection.patch | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/main/musl/0003-handle-loss-of-syslog-socket-connection.patch b/main/musl/0003-handle-loss-of-syslog-socket-connection.patch new file mode 100644 index 0000000000..d33c2ff048 --- /dev/null +++ b/main/musl/0003-handle-loss-of-syslog-socket-connection.patch @@ -0,0 +1,77 @@ +From 0f9c2666aca95eb98eb0ef4f4d8d1473c8ce3fa0 Mon Sep 17 00:00:00 2001 +From: Rich Felker <dalias@aerifal.cx> +Date: Thu, 9 Jul 2015 18:36:02 +0000 +Subject: [PATCH] handle loss of syslog socket connection + +when traditional syslogd implementations are restarted, the old server +socket ceases to exist and a new unix socket with the same pathname is +created. when this happens, the default destination address associated +with the client socket via connect is no longer valid, and attempts to +send produce errors. this happens despite the socket being datagram +type, and is in contrast to the behavior that would be seen with an IP +datagram (UDP) socket. + +in order to avoid a situation where the application is unable to send +further syslog messages without calling closelog, this patch makes +syslog attempt to reconnect the socket when send returns an error +indicating a lost connection. + +additionally, initial failure to connect the socket no longer results +in the socket being closed. this ensures that an application which +calls openlog to reserve the socket file descriptor will not run into +a situation where transient connection failure (e.g. due to syslogd +restart) prevents fd reservation. however, applications which may be +unable to connect the socket later (e.g. due to chroot, restricted +permissions, seccomp, etc.) will still fail to log if the syslog +socket cannot be connected at openlog time or if it has to be +reconnected later. +--- + src/misc/syslog.c | 18 +++++++++++------- + 1 file changed, 11 insertions(+), 7 deletions(-) + +diff --git a/src/misc/syslog.c b/src/misc/syslog.c +index e026f9b..9dd1ddb 100644 +--- a/src/misc/syslog.c ++++ b/src/misc/syslog.c +@@ -48,12 +48,8 @@ void closelog(void) + + static void __openlog() + { +- int fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); +- if (fd < 0) return; +- if (connect(fd, (void *)&log_addr, sizeof log_addr) < 0) +- close(fd); +- else +- log_fd = fd; ++ log_fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0); ++ if (log_fd >= 0) connect(log_fd, (void *)&log_addr, sizeof log_addr); + } + + void openlog(const char *ident, int opt, int facility) +@@ -78,6 +74,11 @@ void openlog(const char *ident, int opt, int facility) + pthread_setcancelstate(cs, 0); + } + ++static int is_lost_conn(int e) ++{ ++ return e==ECONNREFUSED || e==ECONNRESET || e==ENOTCONN || e==EPIPE; ++} ++ + static void _vsyslog(int priority, const char *message, va_list ap) + { + char timebuf[16]; +@@ -107,7 +108,10 @@ static void _vsyslog(int priority, const char *message, va_list ap) + if (l2 >= sizeof buf - l) l = sizeof buf - 1; + else l += l2; + if (buf[l-1] != '\n') buf[l++] = '\n'; +- if (send(log_fd, buf, l, 0) < 0 && (log_opt & LOG_CONS)) { ++ if (send(log_fd, buf, l, 0) < 0 && (!is_lost_conn(errno) ++ || connect(log_fd, (void *)&log_addr, sizeof log_addr) < 0 ++ || send(log_fd, buf, l, 0) < 0) ++ && (log_opt & LOG_CONS)) { + fd = open("/dev/console", O_WRONLY|O_NOCTTY|O_CLOEXEC); + if (fd >= 0) { + dprintf(fd, "%.*s", l-hlen, buf+hlen); +-- +2.4.6 + |