From 11ed95bb53210c322c16bb0897f0cb3b5726ed57 Mon Sep 17 00:00:00 2001 From: Maxim Dounin Date: Fri, 10 Mar 2023 07:43:50 +0300 Subject: Syslog: introduced error log handler. This ensures that errors which happen during logging to syslog are logged with proper context, such as "while logging to syslog" and the server name. Prodded by Safar Safarly. --- src/core/ngx_syslog.c | 47 +++++++++++++++++++++++++++++++++++++++-------- src/core/ngx_syslog.h | 3 ++- 2 files changed, 41 insertions(+), 9 deletions(-) diff --git a/src/core/ngx_syslog.c b/src/core/ngx_syslog.c index 0a64e10b8..bad45bd16 100644 --- a/src/core/ngx_syslog.c +++ b/src/core/ngx_syslog.c @@ -18,6 +18,7 @@ static char *ngx_syslog_parse_args(ngx_conf_t *cf, ngx_syslog_peer_t *peer); static ngx_int_t ngx_syslog_init_peer(ngx_syslog_peer_t *peer); static void ngx_syslog_cleanup(void *data); +static u_char *ngx_syslog_log_error(ngx_log_t *log, u_char *buf, size_t len); static char *facilities[] = { @@ -67,7 +68,7 @@ ngx_syslog_process_conf(ngx_conf_t *cf, ngx_syslog_peer_t *peer) } peer->hostname = &cf->cycle->hostname; - peer->log = &cf->cycle->new_log; + peer->logp = &cf->cycle->new_log; peer->conn.fd = (ngx_socket_t) -1; @@ -289,6 +290,13 @@ ngx_syslog_send(ngx_syslog_peer_t *peer, u_char *buf, size_t len) { ssize_t n; + if (peer->log.handler == NULL) { + peer->log = *peer->logp; + peer->log.handler = ngx_syslog_log_error; + peer->log.data = peer; + peer->log.action = "logging to syslog"; + } + if (peer->conn.fd == (ngx_socket_t) -1) { if (ngx_syslog_init_peer(peer) != NGX_OK) { return NGX_ERROR; @@ -306,7 +314,7 @@ ngx_syslog_send(ngx_syslog_peer_t *peer, u_char *buf, size_t len) if (n == NGX_ERROR) { if (ngx_close_socket(peer->conn.fd) == -1) { - ngx_log_error(NGX_LOG_ALERT, peer->log, ngx_socket_errno, + ngx_log_error(NGX_LOG_ALERT, &peer->log, ngx_socket_errno, ngx_close_socket_n " failed"); } @@ -324,25 +332,25 @@ ngx_syslog_init_peer(ngx_syslog_peer_t *peer) fd = ngx_socket(peer->server.sockaddr->sa_family, SOCK_DGRAM, 0); if (fd == (ngx_socket_t) -1) { - ngx_log_error(NGX_LOG_ALERT, peer->log, ngx_socket_errno, + ngx_log_error(NGX_LOG_ALERT, &peer->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } if (ngx_nonblocking(fd) == -1) { - ngx_log_error(NGX_LOG_ALERT, peer->log, ngx_socket_errno, + ngx_log_error(NGX_LOG_ALERT, &peer->log, ngx_socket_errno, ngx_nonblocking_n " failed"); goto failed; } if (connect(fd, peer->server.sockaddr, peer->server.socklen) == -1) { - ngx_log_error(NGX_LOG_ALERT, peer->log, ngx_socket_errno, + ngx_log_error(NGX_LOG_ALERT, &peer->log, ngx_socket_errno, "connect() failed"); goto failed; } peer->conn.fd = fd; - peer->conn.log = peer->log; + peer->conn.log = &peer->log; /* UDP sockets are always ready to write */ peer->conn.write->ready = 1; @@ -352,7 +360,7 @@ ngx_syslog_init_peer(ngx_syslog_peer_t *peer) failed: if (ngx_close_socket(fd) == -1) { - ngx_log_error(NGX_LOG_ALERT, peer->log, ngx_socket_errno, + ngx_log_error(NGX_LOG_ALERT, &peer->log, ngx_socket_errno, ngx_close_socket_n " failed"); } @@ -373,7 +381,30 @@ ngx_syslog_cleanup(void *data) } if (ngx_close_socket(peer->conn.fd) == -1) { - ngx_log_error(NGX_LOG_ALERT, peer->log, ngx_socket_errno, + ngx_log_error(NGX_LOG_ALERT, &peer->log, ngx_socket_errno, ngx_close_socket_n " failed"); } } + + +static u_char * +ngx_syslog_log_error(ngx_log_t *log, u_char *buf, size_t len) +{ + u_char *p; + ngx_syslog_peer_t *peer; + + p = buf; + + if (log->action) { + p = ngx_snprintf(buf, len, " while %s", log->action); + len -= p - buf; + } + + peer = log->data; + + if (peer) { + p = ngx_snprintf(p, len, ", server: %V", &peer->server.name); + } + + return p; +} diff --git a/src/core/ngx_syslog.h b/src/core/ngx_syslog.h index 181ebe7b3..e2d54acdb 100644 --- a/src/core/ngx_syslog.h +++ b/src/core/ngx_syslog.h @@ -18,7 +18,8 @@ typedef struct { ngx_addr_t server; ngx_connection_t conn; - ngx_log_t *log; + ngx_log_t log; + ngx_log_t *logp; unsigned busy:1; unsigned nohostname:1; -- cgit v1.2.1