view src/core/ngx_syslog.c @ 5742:c45c9812cf11

Core: removed meaningless check from ngx_palloc_block(). The check became meaningless after refactoring in 2a92804f4109. With the loop currently in place, "current" can't be NULL, hence the check can be dropped. Additionally, the local variable "current" was removed to simplify code, and pool->current now used directly instead. Found by Coverity (CID 714236).
author Maxim Dounin <mdounin@mdounin.ru>
date Thu, 26 Jun 2014 03:34:19 +0400
parents 44532046d9d7
children 2cb5275bf5e7
line wrap: on
line source


/*
 * 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 > 'z') {
                    ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                                       "syslog \"tag\" only allows "
                                       "alphanumeric characters");
                    return NGX_CONF_ERROR;
                }
            }

            peer->tag.data = p + 4;
            peer->tag.len = len - 4;

        } 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;

    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->processing) {
        return;
    }

    peer->processing = 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->processing = 0;
}


ssize_t
ngx_syslog_send(ngx_syslog_peer_t *peer, u_char *buf, size_t len)
{
    if (peer->conn.fd == (ngx_socket_t) -1) {
        if (ngx_syslog_init_peer(peer) != NGX_OK) {
            return NGX_ERROR;
        }
    }

    if (ngx_send) {
        return ngx_send(&peer->conn, buf, len);

    } else {
        /* event module has not yet set ngx_io */
        return ngx_os_io.send(&peer->conn, buf, len);
    }
}


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;
    peer->conn.log = &ngx_syslog_dummy_log;

    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;

    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");
    }
}