view src/stream/ngx_stream_access_module.c @ 7354:1812f1d79d84

Fixed socket leak with "return 444" in error_page (ticket #274). Socket leak was observed in the following configuration: error_page 400 = /close; location = /close { return 444; } The problem is that "return 444" triggers termination of the request, and due to error_page termination thinks that it needs to use a posted request to clear stack. But at the early request processing where 400 errors are generated there are no ngx_http_run_posted_requests() calls, so the request is only terminated after an external event. Variants of the problem include "error_page 497" instead (ticket #695) and various other errors generated during early request processing (405, 414, 421, 494, 495, 496, 501, 505). The same problem can be also triggered with "return 499" and "return 408" as both codes trigger ngx_http_terminate_request(), much like "return 444". To fix this, the patch adds ngx_http_run_posted_requests() calls to ngx_http_process_request_line() and ngx_http_process_request_headers() functions, and to ngx_http_v2_run_request() and ngx_http_v2_push_stream() functions in HTTP/2. Since the ngx_http_process_request() function is now only called via other functions which call ngx_http_run_posted_requests(), the call there is no longer needed and was removed.
author Maxim Dounin <mdounin@mdounin.ru>
date Fri, 21 Sep 2018 15:59:30 +0300
parents 72188d1bcab5
children
line wrap: on
line source


/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_stream.h>


typedef struct {
    in_addr_t         mask;
    in_addr_t         addr;
    ngx_uint_t        deny;      /* unsigned  deny:1; */
} ngx_stream_access_rule_t;

#if (NGX_HAVE_INET6)

typedef struct {
    struct in6_addr   addr;
    struct in6_addr   mask;
    ngx_uint_t        deny;      /* unsigned  deny:1; */
} ngx_stream_access_rule6_t;

#endif

#if (NGX_HAVE_UNIX_DOMAIN)

typedef struct {
    ngx_uint_t        deny;      /* unsigned  deny:1; */
} ngx_stream_access_rule_un_t;

#endif

typedef struct {
    ngx_array_t      *rules;     /* array of ngx_stream_access_rule_t */
#if (NGX_HAVE_INET6)
    ngx_array_t      *rules6;    /* array of ngx_stream_access_rule6_t */
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
    ngx_array_t      *rules_un;  /* array of ngx_stream_access_rule_un_t */
#endif
} ngx_stream_access_srv_conf_t;


static ngx_int_t ngx_stream_access_handler(ngx_stream_session_t *s);
static ngx_int_t ngx_stream_access_inet(ngx_stream_session_t *s,
    ngx_stream_access_srv_conf_t *ascf, in_addr_t addr);
#if (NGX_HAVE_INET6)
static ngx_int_t ngx_stream_access_inet6(ngx_stream_session_t *s,
    ngx_stream_access_srv_conf_t *ascf, u_char *p);
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
static ngx_int_t ngx_stream_access_unix(ngx_stream_session_t *s,
    ngx_stream_access_srv_conf_t *ascf);
#endif
static ngx_int_t ngx_stream_access_found(ngx_stream_session_t *s,
    ngx_uint_t deny);
static char *ngx_stream_access_rule(ngx_conf_t *cf, ngx_command_t *cmd,
    void *conf);
static void *ngx_stream_access_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_access_merge_srv_conf(ngx_conf_t *cf,
    void *parent, void *child);
static ngx_int_t ngx_stream_access_init(ngx_conf_t *cf);


static ngx_command_t  ngx_stream_access_commands[] = {

    { ngx_string("allow"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_access_rule,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

    { ngx_string("deny"),
      NGX_STREAM_MAIN_CONF|NGX_STREAM_SRV_CONF|NGX_CONF_TAKE1,
      ngx_stream_access_rule,
      NGX_STREAM_SRV_CONF_OFFSET,
      0,
      NULL },

      ngx_null_command
};



static ngx_stream_module_t  ngx_stream_access_module_ctx = {
    NULL,                                  /* preconfiguration */
    ngx_stream_access_init,                /* postconfiguration */

    NULL,                                  /* create main configuration */
    NULL,                                  /* init main configuration */

    ngx_stream_access_create_srv_conf,     /* create server configuration */
    ngx_stream_access_merge_srv_conf       /* merge server configuration */
};


ngx_module_t  ngx_stream_access_module = {
    NGX_MODULE_V1,
    &ngx_stream_access_module_ctx,         /* module context */
    ngx_stream_access_commands,            /* module directives */
    NGX_STREAM_MODULE,                     /* module type */
    NULL,                                  /* init master */
    NULL,                                  /* init module */
    NULL,                                  /* init process */
    NULL,                                  /* init thread */
    NULL,                                  /* exit thread */
    NULL,                                  /* exit process */
    NULL,                                  /* exit master */
    NGX_MODULE_V1_PADDING
};


static ngx_int_t
ngx_stream_access_handler(ngx_stream_session_t *s)
{
    struct sockaddr_in            *sin;
    ngx_stream_access_srv_conf_t  *ascf;
#if (NGX_HAVE_INET6)
    u_char                        *p;
    in_addr_t                      addr;
    struct sockaddr_in6           *sin6;
#endif

    ascf = ngx_stream_get_module_srv_conf(s, ngx_stream_access_module);

    switch (s->connection->sockaddr->sa_family) {

    case AF_INET:
        if (ascf->rules) {
            sin = (struct sockaddr_in *) s->connection->sockaddr;
            return ngx_stream_access_inet(s, ascf, sin->sin_addr.s_addr);
        }
        break;

#if (NGX_HAVE_INET6)

    case AF_INET6:
        sin6 = (struct sockaddr_in6 *) s->connection->sockaddr;
        p = sin6->sin6_addr.s6_addr;

        if (ascf->rules && IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr)) {
            addr = p[12] << 24;
            addr += p[13] << 16;
            addr += p[14] << 8;
            addr += p[15];
            return ngx_stream_access_inet(s, ascf, htonl(addr));
        }

        if (ascf->rules6) {
            return ngx_stream_access_inet6(s, ascf, p);
        }

        break;

#endif

#if (NGX_HAVE_UNIX_DOMAIN)

    case AF_UNIX:
        if (ascf->rules_un) {
            return ngx_stream_access_unix(s, ascf);
        }

        break;

#endif
    }

    return NGX_DECLINED;
}


static ngx_int_t
ngx_stream_access_inet(ngx_stream_session_t *s,
    ngx_stream_access_srv_conf_t *ascf, in_addr_t addr)
{
    ngx_uint_t                 i;
    ngx_stream_access_rule_t  *rule;

    rule = ascf->rules->elts;
    for (i = 0; i < ascf->rules->nelts; i++) {

        ngx_log_debug3(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                       "access: %08XD %08XD %08XD",
                       addr, rule[i].mask, rule[i].addr);

        if ((addr & rule[i].mask) == rule[i].addr) {
            return ngx_stream_access_found(s, rule[i].deny);
        }
    }

    return NGX_DECLINED;
}


#if (NGX_HAVE_INET6)

static ngx_int_t
ngx_stream_access_inet6(ngx_stream_session_t *s,
    ngx_stream_access_srv_conf_t *ascf, u_char *p)
{
    ngx_uint_t                  n;
    ngx_uint_t                  i;
    ngx_stream_access_rule6_t  *rule6;

    rule6 = ascf->rules6->elts;
    for (i = 0; i < ascf->rules6->nelts; i++) {

#if (NGX_DEBUG)
        {
        size_t  cl, ml, al;
        u_char  ct[NGX_INET6_ADDRSTRLEN];
        u_char  mt[NGX_INET6_ADDRSTRLEN];
        u_char  at[NGX_INET6_ADDRSTRLEN];

        cl = ngx_inet6_ntop(p, ct, NGX_INET6_ADDRSTRLEN);
        ml = ngx_inet6_ntop(rule6[i].mask.s6_addr, mt, NGX_INET6_ADDRSTRLEN);
        al = ngx_inet6_ntop(rule6[i].addr.s6_addr, at, NGX_INET6_ADDRSTRLEN);

        ngx_log_debug6(NGX_LOG_DEBUG_STREAM, s->connection->log, 0,
                       "access: %*s %*s %*s", cl, ct, ml, mt, al, at);
        }
#endif

        for (n = 0; n < 16; n++) {
            if ((p[n] & rule6[i].mask.s6_addr[n]) != rule6[i].addr.s6_addr[n]) {
                goto next;
            }
        }

        return ngx_stream_access_found(s, rule6[i].deny);

    next:
        continue;
    }

    return NGX_DECLINED;
}

#endif


#if (NGX_HAVE_UNIX_DOMAIN)

static ngx_int_t
ngx_stream_access_unix(ngx_stream_session_t *s,
    ngx_stream_access_srv_conf_t *ascf)
{
    ngx_uint_t                    i;
    ngx_stream_access_rule_un_t  *rule_un;

    rule_un = ascf->rules_un->elts;
    for (i = 0; i < ascf->rules_un->nelts; i++) {

        /* TODO: check path */
        if (1) {
            return ngx_stream_access_found(s, rule_un[i].deny);
        }
    }

    return NGX_DECLINED;
}

#endif


static ngx_int_t
ngx_stream_access_found(ngx_stream_session_t *s, ngx_uint_t deny)
{
    if (deny) {
        ngx_log_error(NGX_LOG_ERR, s->connection->log, 0,
                      "access forbidden by rule");
        return NGX_STREAM_FORBIDDEN;
    }

    return NGX_OK;
}


static char *
ngx_stream_access_rule(ngx_conf_t *cf, ngx_command_t *cmd, void *conf)
{
    ngx_stream_access_srv_conf_t *ascf = conf;

    ngx_int_t                     rc;
    ngx_uint_t                    all;
    ngx_str_t                    *value;
    ngx_cidr_t                    cidr;
    ngx_stream_access_rule_t     *rule;
#if (NGX_HAVE_INET6)
    ngx_stream_access_rule6_t    *rule6;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
    ngx_stream_access_rule_un_t  *rule_un;
#endif

    all = 0;
    ngx_memzero(&cidr, sizeof(ngx_cidr_t));

    value = cf->args->elts;

    if (value[1].len == 3 && ngx_strcmp(value[1].data, "all") == 0) {
        all = 1;

#if (NGX_HAVE_UNIX_DOMAIN)
    } else if (value[1].len == 5 && ngx_strcmp(value[1].data, "unix:") == 0) {
        cidr.family = AF_UNIX;
#endif

    } else {
        rc = ngx_ptocidr(&value[1], &cidr);

        if (rc == NGX_ERROR) {
            ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                         "invalid parameter \"%V\"", &value[1]);
            return NGX_CONF_ERROR;
        }

        if (rc == NGX_DONE) {
            ngx_conf_log_error(NGX_LOG_WARN, cf, 0,
                         "low address bits of %V are meaningless", &value[1]);
        }
    }

    if (cidr.family == AF_INET || all) {

        if (ascf->rules == NULL) {
            ascf->rules = ngx_array_create(cf->pool, 4,
                                           sizeof(ngx_stream_access_rule_t));
            if (ascf->rules == NULL) {
                return NGX_CONF_ERROR;
            }
        }

        rule = ngx_array_push(ascf->rules);
        if (rule == NULL) {
            return NGX_CONF_ERROR;
        }

        rule->mask = cidr.u.in.mask;
        rule->addr = cidr.u.in.addr;
        rule->deny = (value[0].data[0] == 'd') ? 1 : 0;
    }

#if (NGX_HAVE_INET6)
    if (cidr.family == AF_INET6 || all) {

        if (ascf->rules6 == NULL) {
            ascf->rules6 = ngx_array_create(cf->pool, 4,
                                            sizeof(ngx_stream_access_rule6_t));
            if (ascf->rules6 == NULL) {
                return NGX_CONF_ERROR;
            }
        }

        rule6 = ngx_array_push(ascf->rules6);
        if (rule6 == NULL) {
            return NGX_CONF_ERROR;
        }

        rule6->mask = cidr.u.in6.mask;
        rule6->addr = cidr.u.in6.addr;
        rule6->deny = (value[0].data[0] == 'd') ? 1 : 0;
    }
#endif

#if (NGX_HAVE_UNIX_DOMAIN)
    if (cidr.family == AF_UNIX || all) {

        if (ascf->rules_un == NULL) {
            ascf->rules_un = ngx_array_create(cf->pool, 1,
                                          sizeof(ngx_stream_access_rule_un_t));
            if (ascf->rules_un == NULL) {
                return NGX_CONF_ERROR;
            }
        }

        rule_un = ngx_array_push(ascf->rules_un);
        if (rule_un == NULL) {
            return NGX_CONF_ERROR;
        }

        rule_un->deny = (value[0].data[0] == 'd') ? 1 : 0;
    }
#endif

    return NGX_CONF_OK;
}


static void *
ngx_stream_access_create_srv_conf(ngx_conf_t *cf)
{
    ngx_stream_access_srv_conf_t  *conf;

    conf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_access_srv_conf_t));
    if (conf == NULL) {
        return NULL;
    }

    return conf;
}


static char *
ngx_stream_access_merge_srv_conf(ngx_conf_t *cf, void *parent, void *child)
{
    ngx_stream_access_srv_conf_t  *prev = parent;
    ngx_stream_access_srv_conf_t  *conf = child;

    if (conf->rules == NULL
#if (NGX_HAVE_INET6)
        && conf->rules6 == NULL
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
        && conf->rules_un == NULL
#endif
    ) {
        conf->rules = prev->rules;
#if (NGX_HAVE_INET6)
        conf->rules6 = prev->rules6;
#endif
#if (NGX_HAVE_UNIX_DOMAIN)
        conf->rules_un = prev->rules_un;
#endif
    }

    return NGX_CONF_OK;
}


static ngx_int_t
ngx_stream_access_init(ngx_conf_t *cf)
{
    ngx_stream_handler_pt        *h;
    ngx_stream_core_main_conf_t  *cmcf;

    cmcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_core_module);

    h = ngx_array_push(&cmcf->phases[NGX_STREAM_ACCESS_PHASE].handlers);
    if (h == NULL) {
        return NGX_ERROR;
    }

    *h = ngx_stream_access_handler;

    return NGX_OK;
}