Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_access_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 | 72188d1bcab5 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { in_addr_t mask; in_addr_t addr; ngx_uint_t deny; /* unsigned deny:1; */ } ngx_http_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_http_access_rule6_t; #endif #if (NGX_HAVE_UNIX_DOMAIN) typedef struct { ngx_uint_t deny; /* unsigned deny:1; */ } ngx_http_access_rule_un_t; #endif typedef struct { ngx_array_t *rules; /* array of ngx_http_access_rule_t */ #if (NGX_HAVE_INET6) ngx_array_t *rules6; /* array of ngx_http_access_rule6_t */ #endif #if (NGX_HAVE_UNIX_DOMAIN) ngx_array_t *rules_un; /* array of ngx_http_access_rule_un_t */ #endif } ngx_http_access_loc_conf_t; static ngx_int_t ngx_http_access_handler(ngx_http_request_t *r); static ngx_int_t ngx_http_access_inet(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, in_addr_t addr); #if (NGX_HAVE_INET6) static ngx_int_t ngx_http_access_inet6(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, u_char *p); #endif #if (NGX_HAVE_UNIX_DOMAIN) static ngx_int_t ngx_http_access_unix(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf); #endif static ngx_int_t ngx_http_access_found(ngx_http_request_t *r, ngx_uint_t deny); static char *ngx_http_access_rule(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static void *ngx_http_access_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_access_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_access_init(ngx_conf_t *cf); static ngx_command_t ngx_http_access_commands[] = { { ngx_string("allow"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF |NGX_CONF_TAKE1, ngx_http_access_rule, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("deny"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LMT_CONF |NGX_CONF_TAKE1, ngx_http_access_rule, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_access_module_ctx = { NULL, /* preconfiguration */ ngx_http_access_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_access_create_loc_conf, /* create location configuration */ ngx_http_access_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_access_module = { NGX_MODULE_V1, &ngx_http_access_module_ctx, /* module context */ ngx_http_access_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_access_handler(ngx_http_request_t *r) { struct sockaddr_in *sin; ngx_http_access_loc_conf_t *alcf; #if (NGX_HAVE_INET6) u_char *p; in_addr_t addr; struct sockaddr_in6 *sin6; #endif alcf = ngx_http_get_module_loc_conf(r, ngx_http_access_module); switch (r->connection->sockaddr->sa_family) { case AF_INET: if (alcf->rules) { sin = (struct sockaddr_in *) r->connection->sockaddr; return ngx_http_access_inet(r, alcf, sin->sin_addr.s_addr); } break; #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) r->connection->sockaddr; p = sin6->sin6_addr.s6_addr; if (alcf->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_http_access_inet(r, alcf, htonl(addr)); } if (alcf->rules6) { return ngx_http_access_inet6(r, alcf, p); } break; #endif #if (NGX_HAVE_UNIX_DOMAIN) case AF_UNIX: if (alcf->rules_un) { return ngx_http_access_unix(r, alcf); } break; #endif } return NGX_DECLINED; } static ngx_int_t ngx_http_access_inet(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, in_addr_t addr) { ngx_uint_t i; ngx_http_access_rule_t *rule; rule = alcf->rules->elts; for (i = 0; i < alcf->rules->nelts; i++) { ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "access: %08XD %08XD %08XD", addr, rule[i].mask, rule[i].addr); if ((addr & rule[i].mask) == rule[i].addr) { return ngx_http_access_found(r, rule[i].deny); } } return NGX_DECLINED; } #if (NGX_HAVE_INET6) static ngx_int_t ngx_http_access_inet6(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf, u_char *p) { ngx_uint_t n; ngx_uint_t i; ngx_http_access_rule6_t *rule6; rule6 = alcf->rules6->elts; for (i = 0; i < alcf->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_HTTP, r->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_http_access_found(r, rule6[i].deny); next: continue; } return NGX_DECLINED; } #endif #if (NGX_HAVE_UNIX_DOMAIN) static ngx_int_t ngx_http_access_unix(ngx_http_request_t *r, ngx_http_access_loc_conf_t *alcf) { ngx_uint_t i; ngx_http_access_rule_un_t *rule_un; rule_un = alcf->rules_un->elts; for (i = 0; i < alcf->rules_un->nelts; i++) { /* TODO: check path */ if (1) { return ngx_http_access_found(r, rule_un[i].deny); } } return NGX_DECLINED; } #endif static ngx_int_t ngx_http_access_found(ngx_http_request_t *r, ngx_uint_t deny) { ngx_http_core_loc_conf_t *clcf; if (deny) { clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (clcf->satisfy == NGX_HTTP_SATISFY_ALL) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "access forbidden by rule"); } return NGX_HTTP_FORBIDDEN; } return NGX_OK; } static char * ngx_http_access_rule(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_access_loc_conf_t *alcf = conf; ngx_int_t rc; ngx_uint_t all; ngx_str_t *value; ngx_cidr_t cidr; ngx_http_access_rule_t *rule; #if (NGX_HAVE_INET6) ngx_http_access_rule6_t *rule6; #endif #if (NGX_HAVE_UNIX_DOMAIN) ngx_http_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 (alcf->rules == NULL) { alcf->rules = ngx_array_create(cf->pool, 4, sizeof(ngx_http_access_rule_t)); if (alcf->rules == NULL) { return NGX_CONF_ERROR; } } rule = ngx_array_push(alcf->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 (alcf->rules6 == NULL) { alcf->rules6 = ngx_array_create(cf->pool, 4, sizeof(ngx_http_access_rule6_t)); if (alcf->rules6 == NULL) { return NGX_CONF_ERROR; } } rule6 = ngx_array_push(alcf->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 (alcf->rules_un == NULL) { alcf->rules_un = ngx_array_create(cf->pool, 1, sizeof(ngx_http_access_rule_un_t)); if (alcf->rules_un == NULL) { return NGX_CONF_ERROR; } } rule_un = ngx_array_push(alcf->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_http_access_create_loc_conf(ngx_conf_t *cf) { ngx_http_access_loc_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_access_loc_conf_t)); if (conf == NULL) { return NULL; } return conf; } static char * ngx_http_access_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_access_loc_conf_t *prev = parent; ngx_http_access_loc_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_http_access_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_ACCESS_PHASE].handlers); if (h == NULL) { return NGX_ERROR; } *h = ngx_http_access_handler; return NGX_OK; }