Mercurial > hg > nginx
view src/http/modules/ngx_http_chunked_filter_module.c @ 9170:c80d111340dc
QUIC: prevented generating ACK frames with discarded keys.
Previously it was possible to generate ACK frames using formally discarded
protection keys, in particular, when acknowledging a client Handshake packet
used to complete the TLS handshake and to discard handshake protection keys.
As it happens late in packet processing, it could be possible to generate ACK
frames after the keys were already discarded.
ACK frames are generated from ngx_quic_ack_packet(), either using a posted
push event, which envolves ngx_quic_generate_ack() as a part of the final
packet assembling, or directly in ngx_quic_ack_packet(), such as when there
is no room to add a new ACK range or when the received packet is out of order.
The added keys availability check is used to avoid generating late ACK frames
in both cases.
author | Sergey Kandaurov <pluknet@nginx.com> |
---|---|
date | Fri, 20 Oct 2023 18:05:07 +0400 |
parents | 1efee5e4194c |
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 { ngx_chain_t *free; ngx_chain_t *busy; } ngx_http_chunked_filter_ctx_t; static ngx_int_t ngx_http_chunked_filter_init(ngx_conf_t *cf); static ngx_chain_t *ngx_http_chunked_create_trailers(ngx_http_request_t *r, ngx_http_chunked_filter_ctx_t *ctx); static ngx_http_module_t ngx_http_chunked_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_chunked_filter_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_chunked_filter_module = { NGX_MODULE_V1, &ngx_http_chunked_filter_module_ctx, /* module context */ NULL, /* 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_chunked_header_filter(ngx_http_request_t *r) { ngx_http_core_loc_conf_t *clcf; ngx_http_chunked_filter_ctx_t *ctx; if (r->headers_out.status == NGX_HTTP_NOT_MODIFIED || r->headers_out.status == NGX_HTTP_NO_CONTENT || r->headers_out.status < NGX_HTTP_OK || r != r->main || r->method == NGX_HTTP_HEAD) { return ngx_http_next_header_filter(r); } if (r->headers_out.content_length_n == -1 || r->expect_trailers) { clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (r->http_version >= NGX_HTTP_VERSION_11 && clcf->chunked_transfer_encoding) { if (r->expect_trailers) { ngx_http_clear_content_length(r); } r->chunked = 1; ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_chunked_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_chunked_filter_module); } else if (r->headers_out.content_length_n == -1) { r->keepalive = 0; } } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_chunked_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { u_char *chunk; off_t size; ngx_int_t rc; ngx_buf_t *b; ngx_chain_t *out, *cl, *tl, **ll; ngx_http_chunked_filter_ctx_t *ctx; if (in == NULL || !r->chunked || r->header_only) { return ngx_http_next_body_filter(r, in); } ctx = ngx_http_get_module_ctx(r, ngx_http_chunked_filter_module); out = NULL; ll = &out; size = 0; cl = in; for ( ;; ) { ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http chunk: %O", ngx_buf_size(cl->buf)); size += ngx_buf_size(cl->buf); if (cl->buf->flush || cl->buf->sync || ngx_buf_in_memory(cl->buf) || cl->buf->in_file) { tl = ngx_alloc_chain_link(r->pool); if (tl == NULL) { return NGX_ERROR; } tl->buf = cl->buf; *ll = tl; ll = &tl->next; } if (cl->next == NULL) { break; } cl = cl->next; } if (size) { tl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (tl == NULL) { return NGX_ERROR; } b = tl->buf; chunk = b->start; if (chunk == NULL) { /* the "0000000000000000" is 64-bit hexadecimal string */ chunk = ngx_palloc(r->pool, sizeof("0000000000000000" CRLF) - 1); if (chunk == NULL) { return NGX_ERROR; } b->start = chunk; b->end = chunk + sizeof("0000000000000000" CRLF) - 1; } b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module; b->memory = 0; b->temporary = 1; b->pos = chunk; b->last = ngx_sprintf(chunk, "%xO" CRLF, size); tl->next = out; out = tl; } if (cl->buf->last_buf) { tl = ngx_http_chunked_create_trailers(r, ctx); if (tl == NULL) { return NGX_ERROR; } cl->buf->last_buf = 0; *ll = tl; if (size == 0) { tl->buf->pos += 2; } } else if (size > 0) { tl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (tl == NULL) { return NGX_ERROR; } b = tl->buf; b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module; b->temporary = 0; b->memory = 1; b->pos = (u_char *) CRLF; b->last = b->pos + 2; *ll = tl; } else { *ll = NULL; } rc = ngx_http_next_body_filter(r, out); ngx_chain_update_chains(r->pool, &ctx->free, &ctx->busy, &out, (ngx_buf_tag_t) &ngx_http_chunked_filter_module); return rc; } static ngx_chain_t * ngx_http_chunked_create_trailers(ngx_http_request_t *r, ngx_http_chunked_filter_ctx_t *ctx) { size_t len; ngx_buf_t *b; ngx_uint_t i; ngx_chain_t *cl; ngx_list_part_t *part; ngx_table_elt_t *header; len = 0; part = &r->headers_out.trailers.part; header = part->elts; for (i = 0; /* void */; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; header = part->elts; i = 0; } if (header[i].hash == 0) { continue; } len += header[i].key.len + sizeof(": ") - 1 + header[i].value.len + sizeof(CRLF) - 1; } cl = ngx_chain_get_free_buf(r->pool, &ctx->free); if (cl == NULL) { return NULL; } b = cl->buf; b->tag = (ngx_buf_tag_t) &ngx_http_chunked_filter_module; b->temporary = 0; b->memory = 1; b->last_buf = 1; if (len == 0) { b->pos = (u_char *) CRLF "0" CRLF CRLF; b->last = b->pos + sizeof(CRLF "0" CRLF CRLF) - 1; return cl; } len += sizeof(CRLF "0" CRLF CRLF) - 1; b->pos = ngx_palloc(r->pool, len); if (b->pos == NULL) { return NULL; } b->last = b->pos; *b->last++ = CR; *b->last++ = LF; *b->last++ = '0'; *b->last++ = CR; *b->last++ = LF; part = &r->headers_out.trailers.part; header = part->elts; for (i = 0; /* void */; i++) { if (i >= part->nelts) { if (part->next == NULL) { break; } part = part->next; header = part->elts; i = 0; } if (header[i].hash == 0) { continue; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http trailer: \"%V: %V\"", &header[i].key, &header[i].value); b->last = ngx_copy(b->last, header[i].key.data, header[i].key.len); *b->last++ = ':'; *b->last++ = ' '; b->last = ngx_copy(b->last, header[i].value.data, header[i].value.len); *b->last++ = CR; *b->last++ = LF; } *b->last++ = CR; *b->last++ = LF; return cl; } static ngx_int_t ngx_http_chunked_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_chunked_header_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_chunked_body_filter; return NGX_OK; }