Mercurial > hg > nginx
view src/http/modules/ngx_http_realip_module.c @ 7629:f47f7d3d1bfa
Mp4: fixed possible chunk offset overflow.
In "co64" atom chunk start offset is a 64-bit unsigned integer. When trimming
the "mdat" atom, chunk offsets are casted to off_t values which are typically
64-bit signed integers. A specially crafted mp4 file with huge chunk offsets
may lead to off_t overflow and result in negative trim boundaries.
The consequences of the overflow are:
- Incorrect Content-Length header value in the response.
- Negative left boundary of the response file buffer holding the trimmed "mdat".
This leads to pread()/sendfile() errors followed by closing the client
connection.
On rare systems where off_t is a 32-bit integer, this scenario is also feasible
with the "stco" atom.
The fix is to add checks which make sure data chunks referenced by each track
are within the mp4 file boundaries. Additionally a few more checks are added to
ensure mp4 file consistency and log errors.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Wed, 26 Feb 2020 15:10:46 +0300 |
parents | 06b01840bd42 |
children | ef6a3a99a81a |
line wrap: on
line source
/* * 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 #define NGX_HTTP_REALIP_PROXY 3 typedef struct { ngx_array_t *from; /* array of ngx_cidr_t */ ngx_uint_t type; ngx_uint_t hash; ngx_str_t header; ngx_flag_t recursive; } 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, ngx_addr_t *addr); 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_add_variables(ngx_conf_t *cf); static ngx_int_t ngx_http_realip_init(ngx_conf_t *cf); static ngx_http_realip_ctx_t *ngx_http_realip_get_module_ctx( ngx_http_request_t *r); static ngx_int_t ngx_http_realip_remote_addr_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static ngx_int_t ngx_http_realip_remote_port_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); 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_string("real_ip_recursive"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_realip_loc_conf_t, recursive), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_realip_module_ctx = { ngx_http_realip_add_variables, /* 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_http_variable_t ngx_http_realip_vars[] = { { ngx_string("realip_remote_addr"), NULL, ngx_http_realip_remote_addr_variable, 0, 0, 0 }, { ngx_string("realip_remote_port"), NULL, ngx_http_realip_remote_port_variable, 0, 0, 0 }, ngx_http_null_variable }; static ngx_int_t ngx_http_realip_handler(ngx_http_request_t *r) { u_char *p; size_t len; ngx_str_t *value; ngx_uint_t i, hash; ngx_addr_t addr; ngx_array_t *xfwd; ngx_list_part_t *part; ngx_table_elt_t *header; ngx_connection_t *c; ngx_http_realip_ctx_t *ctx; ngx_http_realip_loc_conf_t *rlcf; rlcf = ngx_http_get_module_loc_conf(r, ngx_http_realip_module); if (rlcf->from == NULL) { return NGX_DECLINED; } ctx = ngx_http_realip_get_module_ctx(r); if (ctx) { return NGX_DECLINED; } switch (rlcf->type) { case NGX_HTTP_REALIP_XREALIP: if (r->headers_in.x_real_ip == NULL) { return NGX_DECLINED; } value = &r->headers_in.x_real_ip->value; xfwd = NULL; break; case NGX_HTTP_REALIP_XFWD: xfwd = &r->headers_in.x_forwarded_for; if (xfwd->elts == NULL) { return NGX_DECLINED; } value = NULL; break; case NGX_HTTP_REALIP_PROXY: if (r->connection->proxy_protocol == NULL) { return NGX_DECLINED; } value = &r->connection->proxy_protocol->src_addr; xfwd = NULL; 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) { value = &header[i].value; xfwd = NULL; goto found; } } return NGX_DECLINED; } found: c = r->connection; addr.sockaddr = c->sockaddr; addr.socklen = c->socklen; /* addr.name = c->addr_text; */ if (ngx_http_get_forwarded_addr(r, &addr, xfwd, value, rlcf->from, rlcf->recursive) != NGX_DECLINED) { if (rlcf->type == NGX_HTTP_REALIP_PROXY) { ngx_inet_set_port(addr.sockaddr, c->proxy_protocol->src_port); } return ngx_http_realip_set_addr(r, &addr); } return NGX_DECLINED; } static ngx_int_t ngx_http_realip_set_addr(ngx_http_request_t *r, ngx_addr_t *addr) { size_t len; u_char *p; u_char text[NGX_SOCKADDR_STRLEN]; 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; c = r->connection; len = ngx_sock_ntop(addr->sockaddr, addr->socklen, text, NGX_SOCKADDR_STRLEN, 0); if (len == 0) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } p = ngx_pnalloc(c->pool, len); if (p == NULL) { return NGX_HTTP_INTERNAL_SERVER_ERROR; } ngx_memcpy(p, text, len); cln->handler = ngx_http_realip_cleanup; ngx_http_set_ctx(r, ctx, ngx_http_realip_module); 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_url_t u; ngx_cidr_t c, *cidr; ngx_uint_t i; struct sockaddr_in *sin; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; #endif value = cf->args->elts; if (rlcf->from == NULL) { rlcf->from = ngx_array_create(cf->pool, 2, sizeof(ngx_cidr_t)); if (rlcf->from == NULL) { return NGX_CONF_ERROR; } } #if (NGX_HAVE_UNIX_DOMAIN) if (ngx_strcmp(value[1].data, "unix:") == 0) { cidr = ngx_array_push(rlcf->from); if (cidr == NULL) { return NGX_CONF_ERROR; } cidr->family = AF_UNIX; return NGX_CONF_OK; } #endif rc = ngx_ptocidr(&value[1], &c); if (rc != NGX_ERROR) { if (rc == NGX_DONE) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "low address bits of %V are meaningless", &value[1]); } cidr = ngx_array_push(rlcf->from); if (cidr == NULL) { return NGX_CONF_ERROR; } *cidr = c; return NGX_CONF_OK; } ngx_memzero(&u, sizeof(ngx_url_t)); u.host = value[1]; if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) { if (u.err) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "%s in set_real_ip_from \"%V\"", u.err, &u.host); } return NGX_CONF_ERROR; } cidr = ngx_array_push_n(rlcf->from, u.naddrs); if (cidr == NULL) { return NGX_CONF_ERROR; } ngx_memzero(cidr, u.naddrs * sizeof(ngx_cidr_t)); for (i = 0; i < u.naddrs; i++) { cidr[i].family = u.addrs[i].sockaddr->sa_family; switch (cidr[i].family) { #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) u.addrs[i].sockaddr; cidr[i].u.in6.addr = sin6->sin6_addr; ngx_memset(cidr[i].u.in6.mask.s6_addr, 0xff, 16); break; #endif default: /* AF_INET */ sin = (struct sockaddr_in *) u.addrs[i].sockaddr; cidr[i].u.in.addr = sin->sin_addr.s_addr; cidr[i].u.in.mask = 0xffffffff; break; } } 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; if (rlcf->type != NGX_CONF_UNSET_UINT) { return "is duplicate"; } 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; } if (ngx_strcmp(value[1].data, "proxy_protocol") == 0) { rlcf->type = NGX_HTTP_REALIP_PROXY; 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; conf->recursive = NGX_CONF_UNSET; 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; } ngx_conf_merge_uint_value(conf->type, prev->type, NGX_HTTP_REALIP_XREALIP); ngx_conf_merge_value(conf->recursive, prev->recursive, 0); if (conf->header.len == 0) { conf->hash = prev->hash; conf->header = prev->header; } return NGX_CONF_OK; } static ngx_int_t ngx_http_realip_add_variables(ngx_conf_t *cf) { ngx_http_variable_t *var, *v; for (v = ngx_http_realip_vars; v->name.len; v++) { var = ngx_http_add_variable(cf, &v->name, v->flags); if (var == NULL) { return NGX_ERROR; } var->get_handler = v->get_handler; var->data = v->data; } return NGX_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; } static ngx_http_realip_ctx_t * ngx_http_realip_get_module_ctx(ngx_http_request_t *r) { ngx_pool_cleanup_t *cln; ngx_http_realip_ctx_t *ctx; ctx = ngx_http_get_module_ctx(r, ngx_http_realip_module); if (ctx == NULL && (r->internal || r->filter_finalize)) { /* * if module context was reset, the original address * can still be found in the cleanup handler */ for (cln = r->pool->cleanup; cln; cln = cln->next) { if (cln->handler == ngx_http_realip_cleanup) { ctx = cln->data; break; } } } return ctx; } static ngx_int_t ngx_http_realip_remote_addr_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_str_t *addr_text; ngx_http_realip_ctx_t *ctx; ctx = ngx_http_realip_get_module_ctx(r); addr_text = ctx ? &ctx->addr_text : &r->connection->addr_text; v->len = addr_text->len; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->data = addr_text->data; return NGX_OK; } static ngx_int_t ngx_http_realip_remote_port_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { ngx_uint_t port; struct sockaddr *sa; ngx_http_realip_ctx_t *ctx; ctx = ngx_http_realip_get_module_ctx(r); sa = ctx ? ctx->sockaddr : r->connection->sockaddr; v->len = 0; v->valid = 1; v->no_cacheable = 0; v->not_found = 0; v->data = ngx_pnalloc(r->pool, sizeof("65535") - 1); if (v->data == NULL) { return NGX_ERROR; } port = ngx_inet_get_port(sa); if (port > 0 && port < 65536) { v->len = ngx_sprintf(v->data, "%ui", port) - v->data; } return NGX_OK; }