Mercurial > hg > nginx
view src/core/ngx_syslog.c @ 6874:7cc2d3a96ea3
Fixed trailer construction with limit on FreeBSD and macOS.
The ngx_chain_coalesce_file() function may produce more bytes to send then
requested in the limit passed, as it aligns the last file position
to send to memory page boundary. As a result, (limit - send) may become
negative. This resulted in big positive number when converted to size_t
while calling ngx_output_chain_to_iovec().
Another part of the problem is in ngx_chain_coalesce_file(): it changes cl
to the next chain link even if the current buffer is only partially sent
due to limit.
Therefore, if a file buffer was not expected to be fully sent due to limit,
and was followed by a memory buffer, nginx called sendfile() with a part
of the file buffer, and the memory buffer in trailer. If there were enough
room in the socket buffer, this resulted in a part of the file buffer being
skipped, and corresponding part of the memory buffer sent instead.
The bug was introduced in 8e903522c17a (1.7.8). Configurations affected
are ones using limits, that is, limit_rate and/or sendfile_max_chunk, and
memory buffers after file ones (may happen when using subrequests or
with proxying with disk buffering).
Fix is to explicitly check if (send < limit) before constructing trailer
with ngx_output_chain_to_iovec(). Additionally, ngx_chain_coalesce_file()
was modified to preserve unfinished file buffers in cl.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Fri, 20 Jan 2017 21:12:48 +0300 |
parents | 2cd019520210 |
children | fa0e093b64d7 |
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/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #define NGX_SYSLOG_MAX_STR \ NGX_MAX_ERROR_STR + sizeof("<255>Jan 01 00:00:00 ") - 1 \ + (NGX_MAXHOSTNAMELEN - 1) + 1 /* space */ \ + 32 /* tag */ + 2 /* colon, space */ 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 char *facilities[] = { "kern", "user", "mail", "daemon", "auth", "intern", "lpr", "news", "uucp", "clock", "authpriv", "ftp", "ntp", "audit", "alert", "cron", "local0", "local1", "local2", "local3", "local4", "local5", "local6", "local7", NULL }; /* note 'error/warn' like in nginx.conf, not 'err/warning' */ static char *severities[] = { "emerg", "alert", "crit", "error", "warn", "notice", "info", "debug", NULL }; static ngx_log_t ngx_syslog_dummy_log; static ngx_event_t ngx_syslog_dummy_event; char * ngx_syslog_process_conf(ngx_conf_t *cf, ngx_syslog_peer_t *peer) { peer->pool = cf->pool; peer->facility = NGX_CONF_UNSET_UINT; peer->severity = NGX_CONF_UNSET_UINT; if (ngx_syslog_parse_args(cf, peer) != NGX_CONF_OK) { return NGX_CONF_ERROR; } if (peer->server.sockaddr == NULL) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "no syslog server specified"); return NGX_CONF_ERROR; } if (peer->facility == NGX_CONF_UNSET_UINT) { peer->facility = 23; /* local7 */ } if (peer->severity == NGX_CONF_UNSET_UINT) { peer->severity = 6; /* info */ } if (peer->tag.data == NULL) { ngx_str_set(&peer->tag, "nginx"); } peer->conn.fd = (ngx_socket_t) -1; return NGX_CONF_OK; } static char * ngx_syslog_parse_args(ngx_conf_t *cf, ngx_syslog_peer_t *peer) { u_char *p, *comma, c; size_t len; ngx_str_t *value; ngx_url_t u; ngx_uint_t i; value = cf->args->elts; p = value[1].data + sizeof("syslog:") - 1; for ( ;; ) { comma = (u_char *) ngx_strchr(p, ','); if (comma != NULL) { len = comma - p; *comma = '\0'; } else { len = value[1].data + value[1].len - p; } if (ngx_strncmp(p, "server=", 7) == 0) { if (peer->server.sockaddr != NULL) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate syslog \"server\""); return NGX_CONF_ERROR; } ngx_memzero(&u, sizeof(ngx_url_t)); u.url.data = p + 7; u.url.len = len - 7; u.default_port = 514; if (ngx_parse_url(cf->pool, &u) != NGX_OK) { if (u.err) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s in syslog server \"%V\"", u.err, &u.url); } return NGX_CONF_ERROR; } peer->server = u.addrs[0]; } else if (ngx_strncmp(p, "facility=", 9) == 0) { if (peer->facility != NGX_CONF_UNSET_UINT) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate syslog \"facility\""); return NGX_CONF_ERROR; } for (i = 0; facilities[i] != NULL; i++) { if (ngx_strcmp(p + 9, facilities[i]) == 0) { peer->facility = i; goto next; } } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown syslog facility \"%s\"", p + 9); return NGX_CONF_ERROR; } else if (ngx_strncmp(p, "severity=", 9) == 0) { if (peer->severity != NGX_CONF_UNSET_UINT) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate syslog \"severity\""); return NGX_CONF_ERROR; } for (i = 0; severities[i] != NULL; i++) { if (ngx_strcmp(p + 9, severities[i]) == 0) { peer->severity = i; goto next; } } ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown syslog severity \"%s\"", p + 9); return NGX_CONF_ERROR; } else if (ngx_strncmp(p, "tag=", 4) == 0) { if (peer->tag.data != NULL) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "duplicate syslog \"tag\""); return NGX_CONF_ERROR; } /* * RFC 3164: the TAG is a string of ABNF alphanumeric characters * that MUST NOT exceed 32 characters. */ if (len - 4 > 32) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "syslog tag length exceeds 32"); return NGX_CONF_ERROR; } for (i = 4; i < len; i++) { c = ngx_tolower(p[i]); if (c < '0' || (c > '9' && c < 'a' && c != '_') || c > 'z') { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "syslog \"tag\" only allows " "alphanumeric characters " "and underscore"); return NGX_CONF_ERROR; } } peer->tag.data = p + 4; peer->tag.len = len - 4; } else if (len == 10 && ngx_strncmp(p, "nohostname", 10) == 0) { peer->nohostname = 1; } else { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "unknown syslog parameter \"%s\"", p); return NGX_CONF_ERROR; } next: if (comma == NULL) { break; } p = comma + 1; } return NGX_CONF_OK; } u_char * ngx_syslog_add_header(ngx_syslog_peer_t *peer, u_char *buf) { ngx_uint_t pri; pri = peer->facility * 8 + peer->severity; if (peer->nohostname) { return ngx_sprintf(buf, "<%ui>%V %V: ", pri, &ngx_cached_syslog_time, &peer->tag); } return ngx_sprintf(buf, "<%ui>%V %V %V: ", pri, &ngx_cached_syslog_time, &ngx_cycle->hostname, &peer->tag); } void ngx_syslog_writer(ngx_log_t *log, ngx_uint_t level, u_char *buf, size_t len) { u_char *p, msg[NGX_SYSLOG_MAX_STR]; ngx_uint_t head_len; ngx_syslog_peer_t *peer; peer = log->wdata; if (peer->busy) { return; } peer->busy = 1; peer->severity = level - 1; p = ngx_syslog_add_header(peer, msg); head_len = p - msg; len -= NGX_LINEFEED_SIZE; if (len > NGX_SYSLOG_MAX_STR - head_len) { len = NGX_SYSLOG_MAX_STR - head_len; } p = ngx_snprintf(p, len, "%s", buf); (void) ngx_syslog_send(peer, msg, p - msg); peer->busy = 0; } ssize_t ngx_syslog_send(ngx_syslog_peer_t *peer, u_char *buf, size_t len) { ssize_t n; if (peer->conn.fd == (ngx_socket_t) -1) { if (ngx_syslog_init_peer(peer) != NGX_OK) { return NGX_ERROR; } } /* log syslog socket events with valid log */ peer->conn.log = ngx_cycle->log; if (ngx_send) { n = ngx_send(&peer->conn, buf, len); } else { /* event module has not yet set ngx_io */ n = ngx_os_io.send(&peer->conn, buf, len); } #if (NGX_HAVE_UNIX_DOMAIN) if (n == NGX_ERROR && peer->server.sockaddr->sa_family == AF_UNIX) { if (ngx_close_socket(peer->conn.fd) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno, ngx_close_socket_n " failed"); } peer->conn.fd = (ngx_socket_t) -1; } #endif return n; } static ngx_int_t ngx_syslog_init_peer(ngx_syslog_peer_t *peer) { ngx_socket_t fd; ngx_pool_cleanup_t *cln; peer->conn.read = &ngx_syslog_dummy_event; peer->conn.write = &ngx_syslog_dummy_event; ngx_syslog_dummy_event.log = &ngx_syslog_dummy_log; fd = ngx_socket(peer->server.sockaddr->sa_family, SOCK_DGRAM, 0); if (fd == (ngx_socket_t) -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno, ngx_socket_n " failed"); return NGX_ERROR; } if (ngx_nonblocking(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->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, ngx_cycle->log, ngx_socket_errno, "connect() failed"); goto failed; } cln = ngx_pool_cleanup_add(peer->pool, 0); if (cln == NULL) { goto failed; } cln->data = peer; cln->handler = ngx_syslog_cleanup; peer->conn.fd = fd; /* UDP sockets are always ready to write */ peer->conn.write->ready = 1; return NGX_OK; failed: if (ngx_close_socket(fd) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno, ngx_close_socket_n " failed"); } return NGX_ERROR; } static void ngx_syslog_cleanup(void *data) { ngx_syslog_peer_t *peer = data; /* prevents further use of this peer */ peer->busy = 1; if (peer->conn.fd == (ngx_socket_t) -1) { return; } if (ngx_close_socket(peer->conn.fd) == -1) { ngx_log_error(NGX_LOG_ALERT, ngx_cycle->log, ngx_socket_errno, ngx_close_socket_n " failed"); } }