Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_realip_module.c @ 4487:a786c85e8268
Disable symlinks: don't allow creating or truncating a file via a symlink in
the last path component if "if_not_owner" parameter is used.
To prevent race condition we have to open a file before checking its owner and
there's no way to change access flags for already opened file descriptor, so
we disable symlinks for the last path component at all if flags allow creating
or truncating the file.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Tue, 21 Feb 2012 15:04:41 +0000 |
parents | d620f497c50f |
children | b1950b0a9550 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> #define NGX_HTTP_REALIP_XREALIP 0 #define NGX_HTTP_REALIP_XFWD 1 #define NGX_HTTP_REALIP_HEADER 2 typedef struct { in_addr_t mask; in_addr_t addr; } ngx_http_realip_from_t; typedef struct { ngx_array_t *from; /* array of ngx_http_realip_from_t */ ngx_uint_t type; ngx_uint_t hash; ngx_str_t header; #if (NGX_HAVE_UNIX_DOMAIN) ngx_uint_t unixsock; /* unsigned unixsock:2; */ #endif } ngx_http_realip_loc_conf_t; typedef struct { ngx_connection_t *connection; struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t addr_text; } ngx_http_realip_ctx_t; static ngx_int_t ngx_http_realip_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_realip_set_addr(ngx_http_request_t *r, u_char *ip, size_t len); static void ngx_http_realip_cleanup(void *data); static char *ngx_http_realip_from(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_realip(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_http_realip_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_realip_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_realip_init(ngx_conf_t *cf); static ngx_command_t ngx_http_realip_commands[] = { { ngx_string("set_real_ip_from"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_realip_from, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("real_ip_header"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_http_realip, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_realip_module_ctx = { NULL, /* preconfiguration */ ngx_http_realip_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_realip_create_loc_conf, /* create location configuration */ ngx_http_realip_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_realip_module = { NGX_MODULE_V1, &ngx_http_realip_module_ctx, /* module context */ ngx_http_realip_commands, /* module directives */ NGX_HTTP_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_http_realip_handler(ngx_http_request_t *r) { u_char *ip, *p; size_t len; ngx_uint_t i, hash; ngx_list_part_t *part; ngx_table_elt_t *header; struct sockaddr_in *sin; ngx_connection_t *c; ngx_http_realip_ctx_t *ctx; ngx_http_realip_from_t *from; ngx_http_realip_loc_conf_t *rlcf; ctx = ngx_http_get_module_ctx(r, ngx_http_realip_module); if (ctx) { return NGX_DECLINED; } rlcf = ngx_http_get_module_loc_conf(r, ngx_http_realip_module); if (rlcf->from == NULL #if (NGX_HAVE_UNIX_DOMAIN) && !rlcf->unixsock #endif ) { return NGX_DECLINED; } switch (rlcf->type) { case NGX_HTTP_REALIP_XREALIP: if (r->headers_in.x_real_ip == NULL) { return NGX_DECLINED; } len = r->headers_in.x_real_ip->value.len; ip = r->headers_in.x_real_ip->value.data; break; case NGX_HTTP_REALIP_XFWD: if (r->headers_in.x_forwarded_for == NULL) { return NGX_DECLINED; } len = r->headers_in.x_forwarded_for->value.len; ip = r->headers_in.x_forwarded_for->value.data; for (p = ip + len - 1; p > ip; p--) { if (*p == ' ' || *p == ',') { p++; len -= p - ip; ip = p; break; } } break; default: /* NGX_HTTP_REALIP_HEADER */ part = &r->headers_in.headers.part; header = part->elts; hash = rlcf->hash; len = rlcf->header.len; p = rlcf->header.data; for (i = 0; /* void */ ; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; header = part->elts; i = 0; } if (hash == header[i].hash && len == header[i].key.len && ngx_strncmp(p, header[i].lowcase_key, len) == 0) { len = header[i].value.len; ip = header[i].value.data; goto found; } } return NGX_DECLINED; } found: c = r->connection; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "realip: \"%s\"", ip); /* AF_INET only */ if (c->sockaddr->sa_family == AF_INET) { sin = (struct sockaddr_in *) c->sockaddr; from = rlcf->from->elts; for (i = 0; i < rlcf->from->nelts; i++) { ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0, "realip: %08XD %08XD %08XD", sin->sin_addr.s_addr, from[i].mask, from[i].addr); if ((sin->sin_addr.s_addr & from[i].mask) == from[i].addr) { return ngx_http_realip_set_addr(r, ip, len); } } } #if (NGX_HAVE_UNIX_DOMAIN) if (c->sockaddr->sa_family == AF_UNIX && rlcf->unixsock) { return ngx_http_realip_set_addr(r, ip, len); } #endif return NGX_DECLINED; } static ngx_int_t ngx_http_realip_set_addr(ngx_http_request_t *r, u_char *ip, size_t len) { u_char *p; ngx_int_t rc; ngx_addr_t addr; ngx_connection_t *c; ngx_pool_cleanup_t *cln; ngx_http_realip_ctx_t *ctx; cln = ngx_pool_cleanup_add(r->pool, sizeof(ngx_http_realip_ctx_t)); if (cln == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } ctx = cln->data; ngx_http_set_ctx(r, ctx, ngx_http_realip_module); c = r->connection; rc = ngx_parse_addr(c->pool, &addr, ip, len); switch (rc) { case NGX_DECLINED: return NGX_DECLINED; case NGX_ERROR: return NGX_HTTP_INTERNAL_SERVER_ERROR; default: /* NGX_OK */ break; } p = ngx_pnalloc(c->pool, len); if (p == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_memcpy(p, ip, len); cln->handler = ngx_http_realip_cleanup; ctx->connection = c; ctx->sockaddr = c->sockaddr; ctx->socklen = c->socklen; ctx->addr_text = c->addr_text; c->sockaddr = addr.sockaddr; c->socklen = addr.socklen; c->addr_text.len = len; c->addr_text.data = p; return NGX_DECLINED; } static void ngx_http_realip_cleanup(void *data) { ngx_http_realip_ctx_t *ctx = data; ngx_connection_t *c; c = ctx->connection; c->sockaddr = ctx->sockaddr; c->socklen = ctx->socklen; c->addr_text = ctx->addr_text; } static char * ngx_http_realip_from(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_realip_loc_conf_t *rlcf = conf; ngx_int_t rc; ngx_str_t *value; ngx_cidr_t cidr; ngx_http_realip_from_t *from; value = cf->args->elts; #if (NGX_HAVE_UNIX_DOMAIN) if (ngx_strcmp(value[1].data, "unix:") == 0) { rlcf->unixsock = 1; return NGX_CONF_OK; } #endif if (rlcf->from == NULL) { rlcf->from = ngx_array_create(cf->pool, 2, sizeof(ngx_http_realip_from_t)); if (rlcf->from == NULL) { return NGX_CONF_ERROR; } } from = ngx_array_push(rlcf->from); if (from == NULL) { return NGX_CONF_ERROR; } 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 (cidr.family != AF_INET) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "\"set_real_ip_from\" supports IPv4 only"); 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]); } from->mask = cidr.u.in.mask; from->addr = cidr.u.in.addr; return NGX_CONF_OK; } static char * ngx_http_realip(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_realip_loc_conf_t *rlcf = conf; ngx_str_t *value; value = cf->args->elts; if (ngx_strcmp(value[1].data, "X-Real-IP") == 0) { rlcf->type = NGX_HTTP_REALIP_XREALIP; return NGX_CONF_OK; } if (ngx_strcmp(value[1].data, "X-Forwarded-For") == 0) { rlcf->type = NGX_HTTP_REALIP_XFWD; return NGX_CONF_OK; } rlcf->type = NGX_HTTP_REALIP_HEADER; rlcf->hash = ngx_hash_strlow(value[1].data, value[1].data, value[1].len); rlcf->header = value[1]; return NGX_CONF_OK; } static void * ngx_http_realip_create_loc_conf(ngx_conf_t *cf) { ngx_http_realip_loc_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_realip_loc_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->from = NULL; * conf->hash = 0; * conf->header = { 0, NULL }; */ conf->type = NGX_CONF_UNSET_UINT; #if (NGX_HAVE_UNIX_DOMAIN) conf->unixsock = 2; #endif return conf; } static char * ngx_http_realip_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_realip_loc_conf_t *prev = parent; ngx_http_realip_loc_conf_t *conf = child; if (conf->from == NULL) { conf->from = prev->from; } #if (NGX_HAVE_UNIX_DOMAIN) if (conf->unixsock == 2) { conf->unixsock = (prev->unixsock == 2) ? 0 : prev->unixsock; } #endif ngx_conf_merge_uint_value(conf->type, prev->type, NGX_HTTP_REALIP_XREALIP); if (conf->header.len == 0) { conf->hash = prev->hash; conf->header = prev->header; } return NGX_CONF_OK; } static ngx_int_t ngx_http_realip_init(ngx_conf_t *cf) { ngx_http_handler_pt *h; ngx_http_core_main_conf_t *cmcf; cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module); h = ngx_array_push(&cmcf->phases[NGX_HTTP_POST_READ_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_realip_handler; h = ngx_array_push(&cmcf->phases[NGX_HTTP_PREACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_realip_handler; return NGX_OK; }