Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_headers_filter_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 | 6ba68ad8b24c |
children | ef6a3a99a81a |
line wrap: on
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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 ngx_http_header_val_s ngx_http_header_val_t; typedef ngx_int_t (*ngx_http_set_header_pt)(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); typedef struct { ngx_str_t name; ngx_uint_t offset; ngx_http_set_header_pt handler; } ngx_http_set_header_t; struct ngx_http_header_val_s { ngx_http_complex_value_t value; ngx_str_t key; ngx_http_set_header_pt handler; ngx_uint_t offset; ngx_uint_t always; /* unsigned always:1 */ }; typedef enum { NGX_HTTP_EXPIRES_OFF, NGX_HTTP_EXPIRES_EPOCH, NGX_HTTP_EXPIRES_MAX, NGX_HTTP_EXPIRES_ACCESS, NGX_HTTP_EXPIRES_MODIFIED, NGX_HTTP_EXPIRES_DAILY, NGX_HTTP_EXPIRES_UNSET } ngx_http_expires_t; typedef struct { ngx_http_expires_t expires; time_t expires_time; ngx_http_complex_value_t *expires_value; ngx_array_t *headers; ngx_array_t *trailers; } ngx_http_headers_conf_t; static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf); static ngx_int_t ngx_http_parse_expires(ngx_str_t *value, ngx_http_expires_t *expires, time_t *expires_time, char **err); static ngx_int_t ngx_http_add_multi_header_lines(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static ngx_int_t ngx_http_add_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static ngx_int_t ngx_http_set_response_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value); static void *ngx_http_headers_create_conf(ngx_conf_t *cf); static char *ngx_http_headers_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_headers_filter_init(ngx_conf_t *cf); static char *ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static char *ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_http_set_header_t ngx_http_set_headers[] = { { ngx_string("Cache-Control"), offsetof(ngx_http_headers_out_t, cache_control), ngx_http_add_multi_header_lines }, { ngx_string("Link"), offsetof(ngx_http_headers_out_t, link), ngx_http_add_multi_header_lines }, { ngx_string("Last-Modified"), offsetof(ngx_http_headers_out_t, last_modified), ngx_http_set_last_modified }, { ngx_string("ETag"), offsetof(ngx_http_headers_out_t, etag), ngx_http_set_response_header }, { ngx_null_string, 0, NULL } }; static ngx_command_t ngx_http_headers_filter_commands[] = { { ngx_string("expires"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF |NGX_CONF_TAKE12, ngx_http_headers_expires, NGX_HTTP_LOC_CONF_OFFSET, 0, NULL }, { ngx_string("add_header"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF |NGX_CONF_TAKE23, ngx_http_headers_add, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_headers_conf_t, headers), NULL }, { ngx_string("add_trailer"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_HTTP_LIF_CONF |NGX_CONF_TAKE23, ngx_http_headers_add, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_headers_conf_t, trailers), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_headers_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_headers_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_headers_create_conf, /* create location configuration */ ngx_http_headers_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_headers_filter_module = { NGX_MODULE_V1, &ngx_http_headers_filter_module_ctx, /* module context */ ngx_http_headers_filter_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_output_header_filter_pt ngx_http_next_header_filter; static ngx_http_output_body_filter_pt ngx_http_next_body_filter; static ngx_int_t ngx_http_headers_filter(ngx_http_request_t *r) { ngx_str_t value; ngx_uint_t i, safe_status; ngx_http_header_val_t *h; ngx_http_headers_conf_t *conf; if (r != r->main) { return ngx_http_next_header_filter(r); } conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module); if (conf->expires == NGX_HTTP_EXPIRES_OFF && conf->headers == NULL && conf->trailers == NULL) { return ngx_http_next_header_filter(r); } switch (r->headers_out.status) { case NGX_HTTP_OK: case NGX_HTTP_CREATED: case NGX_HTTP_NO_CONTENT: case NGX_HTTP_PARTIAL_CONTENT: case NGX_HTTP_MOVED_PERMANENTLY: case NGX_HTTP_MOVED_TEMPORARILY: case NGX_HTTP_SEE_OTHER: case NGX_HTTP_NOT_MODIFIED: case NGX_HTTP_TEMPORARY_REDIRECT: case NGX_HTTP_PERMANENT_REDIRECT: safe_status = 1; break; default: safe_status = 0; break; } if (conf->expires != NGX_HTTP_EXPIRES_OFF && safe_status) { if (ngx_http_set_expires(r, conf) != NGX_OK) { return NGX_ERROR; } } if (conf->headers) { h = conf->headers->elts; for (i = 0; i < conf->headers->nelts; i++) { if (!safe_status && !h[i].always) { continue; } if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) { return NGX_ERROR; } if (h[i].handler(r, &h[i], &value) != NGX_OK) { return NGX_ERROR; } } } if (conf->trailers) { h = conf->trailers->elts; for (i = 0; i < conf->trailers->nelts; i++) { if (!safe_status && !h[i].always) { continue; } r->expect_trailers = 1; break; } } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_trailers_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_str_t value; ngx_uint_t i, safe_status; ngx_chain_t *cl; ngx_table_elt_t *t; ngx_http_header_val_t *h; ngx_http_headers_conf_t *conf; conf = ngx_http_get_module_loc_conf(r, ngx_http_headers_filter_module); if (in == NULL || conf->trailers == NULL || !r->expect_trailers || r->header_only) { return ngx_http_next_body_filter(r, in); } for (cl = in; cl; cl = cl->next) { if (cl->buf->last_buf) { break; } } if (cl == NULL) { return ngx_http_next_body_filter(r, in); } switch (r->headers_out.status) { case NGX_HTTP_OK: case NGX_HTTP_CREATED: case NGX_HTTP_NO_CONTENT: case NGX_HTTP_PARTIAL_CONTENT: case NGX_HTTP_MOVED_PERMANENTLY: case NGX_HTTP_MOVED_TEMPORARILY: case NGX_HTTP_SEE_OTHER: case NGX_HTTP_NOT_MODIFIED: case NGX_HTTP_TEMPORARY_REDIRECT: case NGX_HTTP_PERMANENT_REDIRECT: safe_status = 1; break; default: safe_status = 0; break; } h = conf->trailers->elts; for (i = 0; i < conf->trailers->nelts; i++) { if (!safe_status && !h[i].always) { continue; } if (ngx_http_complex_value(r, &h[i].value, &value) != NGX_OK) { return NGX_ERROR; } if (value.len) { t = ngx_list_push(&r->headers_out.trailers); if (t == NULL) { return NGX_ERROR; } t->key = h[i].key; t->value = value; t->hash = 1; } } return ngx_http_next_body_filter(r, in); } static ngx_int_t ngx_http_set_expires(ngx_http_request_t *r, ngx_http_headers_conf_t *conf) { char *err; size_t len; time_t now, expires_time, max_age; ngx_str_t value; ngx_int_t rc; ngx_uint_t i; ngx_table_elt_t *e, *cc, **ccp; ngx_http_expires_t expires; expires = conf->expires; expires_time = conf->expires_time; if (conf->expires_value != NULL) { if (ngx_http_complex_value(r, conf->expires_value, &value) != NGX_OK) { return NGX_ERROR; } rc = ngx_http_parse_expires(&value, &expires, &expires_time, &err); if (rc != NGX_OK) { return NGX_OK; } if (expires == NGX_HTTP_EXPIRES_OFF) { return NGX_OK; } } e = r->headers_out.expires; if (e == NULL) { e = ngx_list_push(&r->headers_out.headers); if (e == NULL) { return NGX_ERROR; } r->headers_out.expires = e; e->hash = 1; ngx_str_set(&e->key, "Expires"); } len = sizeof("Mon, 28 Sep 1970 06:00:00 GMT"); e->value.len = len - 1; ccp = r->headers_out.cache_control.elts; if (ccp == NULL) { if (ngx_array_init(&r->headers_out.cache_control, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) { return NGX_ERROR; } cc = ngx_list_push(&r->headers_out.headers); if (cc == NULL) { return NGX_ERROR; } cc->hash = 1; ngx_str_set(&cc->key, "Cache-Control"); ccp = ngx_array_push(&r->headers_out.cache_control); if (ccp == NULL) { return NGX_ERROR; } *ccp = cc; } else { for (i = 1; i < r->headers_out.cache_control.nelts; i++) { ccp[i]->hash = 0; } cc = ccp[0]; } if (expires == NGX_HTTP_EXPIRES_EPOCH) { e->value.data = (u_char *) "Thu, 01 Jan 1970 00:00:01 GMT"; ngx_str_set(&cc->value, "no-cache"); return NGX_OK; } if (expires == NGX_HTTP_EXPIRES_MAX) { e->value.data = (u_char *) "Thu, 31 Dec 2037 23:55:55 GMT"; /* 10 years */ ngx_str_set(&cc->value, "max-age=315360000"); return NGX_OK; } e->value.data = ngx_pnalloc(r->pool, len); if (e->value.data == NULL) { return NGX_ERROR; } if (expires_time == 0 && expires != NGX_HTTP_EXPIRES_DAILY) { ngx_memcpy(e->value.data, ngx_cached_http_time.data, ngx_cached_http_time.len + 1); ngx_str_set(&cc->value, "max-age=0"); return NGX_OK; } now = ngx_time(); if (expires == NGX_HTTP_EXPIRES_DAILY) { expires_time = ngx_next_time(expires_time); max_age = expires_time - now; } else if (expires == NGX_HTTP_EXPIRES_ACCESS || r->headers_out.last_modified_time == -1) { max_age = expires_time; expires_time += now; } else { expires_time += r->headers_out.last_modified_time; max_age = expires_time - now; } ngx_http_time(e->value.data, expires_time); if (conf->expires_time < 0 || max_age < 0) { ngx_str_set(&cc->value, "no-cache"); return NGX_OK; } cc->value.data = ngx_pnalloc(r->pool, sizeof("max-age=") + NGX_TIME_T_LEN + 1); if (cc->value.data == NULL) { return NGX_ERROR; } cc->value.len = ngx_sprintf(cc->value.data, "max-age=%T", max_age) - cc->value.data; return NGX_OK; } static ngx_int_t ngx_http_parse_expires(ngx_str_t *value, ngx_http_expires_t *expires, time_t *expires_time, char **err) { ngx_uint_t minus; if (*expires != NGX_HTTP_EXPIRES_MODIFIED) { if (value->len == 5 && ngx_strncmp(value->data, "epoch", 5) == 0) { *expires = NGX_HTTP_EXPIRES_EPOCH; return NGX_OK; } if (value->len == 3 && ngx_strncmp(value->data, "max", 3) == 0) { *expires = NGX_HTTP_EXPIRES_MAX; return NGX_OK; } if (value->len == 3 && ngx_strncmp(value->data, "off", 3) == 0) { *expires = NGX_HTTP_EXPIRES_OFF; return NGX_OK; } } if (value->len && value->data[0] == '@') { value->data++; value->len--; minus = 0; if (*expires == NGX_HTTP_EXPIRES_MODIFIED) { *err = "daily time cannot be used with \"modified\" parameter"; return NGX_ERROR; } *expires = NGX_HTTP_EXPIRES_DAILY; } else if (value->len && value->data[0] == '+') { value->data++; value->len--; minus = 0; } else if (value->len && value->data[0] == '-') { value->data++; value->len--; minus = 1; } else { minus = 0; } *expires_time = ngx_parse_time(value, 1); if (*expires_time == (time_t) NGX_ERROR) { *err = "invalid value"; return NGX_ERROR; } if (*expires == NGX_HTTP_EXPIRES_DAILY && *expires_time > 24 * 60 * 60) { *err = "daily time value must be less than 24 hours"; return NGX_ERROR; } if (minus) { *expires_time = - *expires_time; } return NGX_OK; } static ngx_int_t ngx_http_add_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { ngx_table_elt_t *h; if (value->len) { h = ngx_list_push(&r->headers_out.headers); if (h == NULL) { return NGX_ERROR; } h->hash = 1; h->key = hv->key; h->value = *value; } return NGX_OK; } static ngx_int_t ngx_http_add_multi_header_lines(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { ngx_array_t *pa; ngx_table_elt_t *h, **ph; if (value->len == 0) { return NGX_OK; } pa = (ngx_array_t *) ((char *) &r->headers_out + hv->offset); if (pa->elts == NULL) { if (ngx_array_init(pa, r->pool, 1, sizeof(ngx_table_elt_t *)) != NGX_OK) { return NGX_ERROR; } } h = ngx_list_push(&r->headers_out.headers); if (h == NULL) { return NGX_ERROR; } h->hash = 1; h->key = hv->key; h->value = *value; ph = ngx_array_push(pa); if (ph == NULL) { return NGX_ERROR; } *ph = h; return NGX_OK; } static ngx_int_t ngx_http_set_last_modified(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { if (ngx_http_set_response_header(r, hv, value) != NGX_OK) { return NGX_ERROR; } r->headers_out.last_modified_time = (value->len) ? ngx_parse_http_time(value->data, value->len) : -1; return NGX_OK; } static ngx_int_t ngx_http_set_response_header(ngx_http_request_t *r, ngx_http_header_val_t *hv, ngx_str_t *value) { ngx_table_elt_t *h, **old; old = (ngx_table_elt_t **) ((char *) &r->headers_out + hv->offset); if (value->len == 0) { if (*old) { (*old)->hash = 0; *old = NULL; } return NGX_OK; } if (*old) { h = *old; } else { h = ngx_list_push(&r->headers_out.headers); if (h == NULL) { return NGX_ERROR; } *old = h; } h->hash = 1; h->key = hv->key; h->value = *value; return NGX_OK; } static void * ngx_http_headers_create_conf(ngx_conf_t *cf) { ngx_http_headers_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_headers_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->headers = NULL; * conf->trailers = NULL; * conf->expires_time = 0; * conf->expires_value = NULL; */ conf->expires = NGX_HTTP_EXPIRES_UNSET; return conf; } static char * ngx_http_headers_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_headers_conf_t *prev = parent; ngx_http_headers_conf_t *conf = child; if (conf->expires == NGX_HTTP_EXPIRES_UNSET) { conf->expires = prev->expires; conf->expires_time = prev->expires_time; conf->expires_value = prev->expires_value; if (conf->expires == NGX_HTTP_EXPIRES_UNSET) { conf->expires = NGX_HTTP_EXPIRES_OFF; } } if (conf->headers == NULL) { conf->headers = prev->headers; } if (conf->trailers == NULL) { conf->trailers = prev->trailers; } return NGX_CONF_OK; } static ngx_int_t ngx_http_headers_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_headers_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_trailers_filter; return NGX_OK; } static char * ngx_http_headers_expires(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_headers_conf_t *hcf = conf; char *err; ngx_str_t *value; ngx_int_t rc; ngx_uint_t n; ngx_http_complex_value_t cv; ngx_http_compile_complex_value_t ccv; if (hcf->expires != NGX_HTTP_EXPIRES_UNSET) { return "is duplicate"; } value = cf->args->elts; if (cf->args->nelts == 2) { hcf->expires = NGX_HTTP_EXPIRES_ACCESS; n = 1; } else { /* cf->args->nelts == 3 */ if (ngx_strcmp(value[1].data, "modified") != 0) { return "invalid value"; } hcf->expires = NGX_HTTP_EXPIRES_MODIFIED; n = 2; } ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[n]; ccv.complex_value = &cv; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } if (cv.lengths != NULL) { hcf->expires_value = ngx_palloc(cf->pool, sizeof(ngx_http_complex_value_t)); if (hcf->expires_value == NULL) { return NGX_CONF_ERROR; } *hcf->expires_value = cv; return NGX_CONF_OK; } rc = ngx_http_parse_expires(&value[n], &hcf->expires, &hcf->expires_time, &err); if (rc != NGX_OK) { return err; } return NGX_CONF_OK; } static char * ngx_http_headers_add(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_headers_conf_t *hcf = conf; ngx_str_t *value; ngx_uint_t i; ngx_array_t **headers; ngx_http_header_val_t *hv; ngx_http_set_header_t *set; ngx_http_compile_complex_value_t ccv; value = cf->args->elts; headers = (ngx_array_t **) ((char *) hcf + cmd->offset); if (*headers == NULL) { *headers = ngx_array_create(cf->pool, 1, sizeof(ngx_http_header_val_t)); if (*headers == NULL) { return NGX_CONF_ERROR; } } hv = ngx_array_push(*headers); if (hv == NULL) { return NGX_CONF_ERROR; } hv->key = value[1]; hv->handler = NULL; hv->offset = 0; hv->always = 0; if (headers == &hcf->headers) { hv->handler = ngx_http_add_header; set = ngx_http_set_headers; for (i = 0; set[i].name.len; i++) { if (ngx_strcasecmp(value[1].data, set[i].name.data) != 0) { continue; } hv->offset = set[i].offset; hv->handler = set[i].handler; break; } } if (value[2].len == 0) { ngx_memzero(&hv->value, sizeof(ngx_http_complex_value_t)); } else { ngx_memzero(&ccv, sizeof(ngx_http_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[2]; ccv.complex_value = &hv->value; if (ngx_http_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } } if (cf->args->nelts == 3) { return NGX_CONF_OK; } if (ngx_strcmp(value[3].data, "always") != 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[3]); return NGX_CONF_ERROR; } hv->always = 1; return NGX_CONF_OK; }