Mercurial > hg > nginx
view src/http/modules/ngx_http_range_filter_module.c @ 7507:ea05113adbdb
Range filter: fixed loss of incoming chain links.
Filters are not allowed to change incoming chain links, and should allocate
their own links if any modifications are needed. Nevertheless
ngx_http_range_singlepart_body() modified incoming chain links in some
cases, notably at the end of the requested range.
No problems caused by this are currently known, mostly because of
limited number of possible modifications and the position of the range
body filter in the filter chain. Though this behaviour is clearly incorrect
and tests demonstrate that it can at least cause some proxy buffers being
lost when using proxy_force_ranges, leading to less effective handling
of responses.
Fix is to always allocate new chain links in ngx_http_range_singlepart_body().
Links are explicitly freed to ensure constant memory usage with long-lived
requests.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 13 May 2019 22:44:02 +0300 |
parents | a2f5e25d6a28 |
children | c30a20e06c21 |
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> /* * the single part format: * * "HTTP/1.0 206 Partial Content" CRLF * ... header ... * "Content-Type: image/jpeg" CRLF * "Content-Length: SIZE" CRLF * "Content-Range: bytes START-END/SIZE" CRLF * CRLF * ... data ... * * * the multipart format: * * "HTTP/1.0 206 Partial Content" CRLF * ... header ... * "Content-Type: multipart/byteranges; boundary=0123456789" CRLF * CRLF * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes START0-END0/SIZE" CRLF * CRLF * ... data ... * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes START1-END1/SIZE" CRLF * CRLF * ... data ... * CRLF * "--0123456789--" CRLF */ typedef struct { off_t start; off_t end; ngx_str_t content_range; } ngx_http_range_t; typedef struct { off_t offset; ngx_str_t boundary_header; ngx_array_t ranges; } ngx_http_range_filter_ctx_t; static ngx_int_t ngx_http_range_parse(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_uint_t ranges); static ngx_int_t ngx_http_range_singlepart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx); static ngx_int_t ngx_http_range_multipart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx); static ngx_int_t ngx_http_range_not_satisfiable(ngx_http_request_t *r); static ngx_int_t ngx_http_range_test_overlapped(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in); static ngx_int_t ngx_http_range_singlepart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in); static ngx_int_t ngx_http_range_multipart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in); static ngx_int_t ngx_http_range_header_filter_init(ngx_conf_t *cf); static ngx_int_t ngx_http_range_body_filter_init(ngx_conf_t *cf); static ngx_http_module_t ngx_http_range_header_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_range_header_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_range_header_filter_module = { NGX_MODULE_V1, &ngx_http_range_header_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_module_t ngx_http_range_body_filter_module_ctx = { NULL, /* preconfiguration */ ngx_http_range_body_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_range_body_filter_module = { NGX_MODULE_V1, &ngx_http_range_body_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_range_header_filter(ngx_http_request_t *r) { time_t if_range_time; ngx_str_t *if_range, *etag; ngx_uint_t ranges; ngx_http_core_loc_conf_t *clcf; ngx_http_range_filter_ctx_t *ctx; if (r->http_version < NGX_HTTP_VERSION_10 || r->headers_out.status != NGX_HTTP_OK || (r != r->main && !r->subrequest_ranges) || r->headers_out.content_length_n == -1 || !r->allow_ranges) { return ngx_http_next_header_filter(r); } clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); if (clcf->max_ranges == 0) { return ngx_http_next_header_filter(r); } if (r->headers_in.range == NULL || r->headers_in.range->value.len < 7 || ngx_strncasecmp(r->headers_in.range->value.data, (u_char *) "bytes=", 6) != 0) { goto next_filter; } if (r->headers_in.if_range) { if_range = &r->headers_in.if_range->value; if (if_range->len >= 2 && if_range->data[if_range->len - 1] == '"') { if (r->headers_out.etag == NULL) { goto next_filter; } etag = &r->headers_out.etag->value; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http ir:%V etag:%V", if_range, etag); if (if_range->len != etag->len || ngx_strncmp(if_range->data, etag->data, etag->len) != 0) { goto next_filter; } goto parse; } if (r->headers_out.last_modified_time == (time_t) -1) { goto next_filter; } if_range_time = ngx_parse_http_time(if_range->data, if_range->len); ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http ir:%T lm:%T", if_range_time, r->headers_out.last_modified_time); if (if_range_time != r->headers_out.last_modified_time) { goto next_filter; } } parse: ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_range_filter_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ctx->offset = r->headers_out.content_offset; ranges = r->single_range ? 1 : clcf->max_ranges; switch (ngx_http_range_parse(r, ctx, ranges)) { case NGX_OK: ngx_http_set_ctx(r, ctx, ngx_http_range_body_filter_module); r->headers_out.status = NGX_HTTP_PARTIAL_CONTENT; r->headers_out.status_line.len = 0; if (ctx->ranges.nelts == 1) { return ngx_http_range_singlepart_header(r, ctx); } return ngx_http_range_multipart_header(r, ctx); case NGX_HTTP_RANGE_NOT_SATISFIABLE: return ngx_http_range_not_satisfiable(r); case NGX_ERROR: return NGX_ERROR; default: /* NGX_DECLINED */ break; } next_filter: r->headers_out.accept_ranges = ngx_list_push(&r->headers_out.headers); if (r->headers_out.accept_ranges == NULL) { return NGX_ERROR; } r->headers_out.accept_ranges->hash = 1; ngx_str_set(&r->headers_out.accept_ranges->key, "Accept-Ranges"); ngx_str_set(&r->headers_out.accept_ranges->value, "bytes"); return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_range_parse(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_uint_t ranges) { u_char *p; off_t start, end, size, content_length, cutoff, cutlim; ngx_uint_t suffix; ngx_http_range_t *range; ngx_http_range_filter_ctx_t *mctx; if (r != r->main) { mctx = ngx_http_get_module_ctx(r->main, ngx_http_range_body_filter_module); if (mctx) { ctx->ranges = mctx->ranges; return NGX_OK; } } if (ngx_array_init(&ctx->ranges, r->pool, 1, sizeof(ngx_http_range_t)) != NGX_OK) { return NGX_ERROR; } p = r->headers_in.range->value.data + 6; size = 0; content_length = r->headers_out.content_length_n; cutoff = NGX_MAX_OFF_T_VALUE / 10; cutlim = NGX_MAX_OFF_T_VALUE % 10; for ( ;; ) { start = 0; end = 0; suffix = 0; while (*p == ' ') { p++; } if (*p != '-') { if (*p < '0' || *p > '9') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } while (*p >= '0' && *p <= '9') { if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } start = start * 10 + (*p++ - '0'); } while (*p == ' ') { p++; } if (*p++ != '-') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } while (*p == ' ') { p++; } if (*p == ',' || *p == '\0') { end = content_length; goto found; } } else { suffix = 1; p++; } if (*p < '0' || *p > '9') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } while (*p >= '0' && *p <= '9') { if (end >= cutoff && (end > cutoff || *p - '0' > cutlim)) { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } end = end * 10 + (*p++ - '0'); } while (*p == ' ') { p++; } if (*p != ',' && *p != '\0') { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } if (suffix) { start = (end < content_length) ? content_length - end : 0; end = content_length - 1; } if (end >= content_length) { end = content_length; } else { end++; } found: if (start < end) { range = ngx_array_push(&ctx->ranges); if (range == NULL) { return NGX_ERROR; } range->start = start; range->end = end; if (size > NGX_MAX_OFF_T_VALUE - (end - start)) { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } size += end - start; if (ranges-- == 0) { return NGX_DECLINED; } } else if (start == 0) { return NGX_DECLINED; } if (*p++ != ',') { break; } } if (ctx->ranges.nelts == 0) { return NGX_HTTP_RANGE_NOT_SATISFIABLE; } if (size > content_length) { return NGX_DECLINED; } return NGX_OK; } static ngx_int_t ngx_http_range_singlepart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx) { ngx_table_elt_t *content_range; ngx_http_range_t *range; if (r != r->main) { return ngx_http_next_header_filter(r); } content_range = ngx_list_push(&r->headers_out.headers); if (content_range == NULL) { return NGX_ERROR; } r->headers_out.content_range = content_range; content_range->hash = 1; ngx_str_set(&content_range->key, "Content-Range"); content_range->value.data = ngx_pnalloc(r->pool, sizeof("bytes -/") - 1 + 3 * NGX_OFF_T_LEN); if (content_range->value.data == NULL) { content_range->hash = 0; r->headers_out.content_range = NULL; return NGX_ERROR; } /* "Content-Range: bytes SSSS-EEEE/TTTT" header */ range = ctx->ranges.elts; content_range->value.len = ngx_sprintf(content_range->value.data, "bytes %O-%O/%O", range->start, range->end - 1, r->headers_out.content_length_n) - content_range->value.data; r->headers_out.content_length_n = range->end - range->start; r->headers_out.content_offset = range->start; if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_range_multipart_header(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx) { off_t len; size_t size; ngx_uint_t i; ngx_http_range_t *range; ngx_atomic_uint_t boundary; size = sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN + sizeof(CRLF "Content-Type: ") - 1 + r->headers_out.content_type.len + sizeof(CRLF "Content-Range: bytes ") - 1; if (r->headers_out.content_type_len == r->headers_out.content_type.len && r->headers_out.charset.len) { size += sizeof("; charset=") - 1 + r->headers_out.charset.len; } ctx->boundary_header.data = ngx_pnalloc(r->pool, size); if (ctx->boundary_header.data == NULL) { return NGX_ERROR; } boundary = ngx_next_temp_number(0); /* * The boundary header of the range: * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes " */ if (r->headers_out.content_type_len == r->headers_out.content_type.len && r->headers_out.charset.len) { ctx->boundary_header.len = ngx_sprintf(ctx->boundary_header.data, CRLF "--%0muA" CRLF "Content-Type: %V; charset=%V" CRLF "Content-Range: bytes ", boundary, &r->headers_out.content_type, &r->headers_out.charset) - ctx->boundary_header.data; } else if (r->headers_out.content_type.len) { ctx->boundary_header.len = ngx_sprintf(ctx->boundary_header.data, CRLF "--%0muA" CRLF "Content-Type: %V" CRLF "Content-Range: bytes ", boundary, &r->headers_out.content_type) - ctx->boundary_header.data; } else { ctx->boundary_header.len = ngx_sprintf(ctx->boundary_header.data, CRLF "--%0muA" CRLF "Content-Range: bytes ", boundary) - ctx->boundary_header.data; } r->headers_out.content_type.data = ngx_pnalloc(r->pool, sizeof("Content-Type: multipart/byteranges; boundary=") - 1 + NGX_ATOMIC_T_LEN); if (r->headers_out.content_type.data == NULL) { return NGX_ERROR; } r->headers_out.content_type_lowcase = NULL; /* "Content-Type: multipart/byteranges; boundary=0123456789" */ r->headers_out.content_type.len = ngx_sprintf(r->headers_out.content_type.data, "multipart/byteranges; boundary=%0muA", boundary) - r->headers_out.content_type.data; r->headers_out.content_type_len = r->headers_out.content_type.len; r->headers_out.charset.len = 0; /* the size of the last boundary CRLF "--0123456789--" CRLF */ len = sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN + sizeof("--" CRLF) - 1; range = ctx->ranges.elts; for (i = 0; i < ctx->ranges.nelts; i++) { /* the size of the range: "SSSS-EEEE/TTTT" CRLF CRLF */ range[i].content_range.data = ngx_pnalloc(r->pool, 3 * NGX_OFF_T_LEN + 2 + 4); if (range[i].content_range.data == NULL) { return NGX_ERROR; } range[i].content_range.len = ngx_sprintf(range[i].content_range.data, "%O-%O/%O" CRLF CRLF, range[i].start, range[i].end - 1, r->headers_out.content_length_n) - range[i].content_range.data; len += ctx->boundary_header.len + range[i].content_range.len + (range[i].end - range[i].start); } r->headers_out.content_length_n = len; if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_range_not_satisfiable(ngx_http_request_t *r) { ngx_table_elt_t *content_range; r->headers_out.status = NGX_HTTP_RANGE_NOT_SATISFIABLE; content_range = ngx_list_push(&r->headers_out.headers); if (content_range == NULL) { return NGX_ERROR; } r->headers_out.content_range = content_range; content_range->hash = 1; ngx_str_set(&content_range->key, "Content-Range"); content_range->value.data = ngx_pnalloc(r->pool, sizeof("bytes */") - 1 + NGX_OFF_T_LEN); if (content_range->value.data == NULL) { content_range->hash = 0; r->headers_out.content_range = NULL; return NGX_ERROR; } content_range->value.len = ngx_sprintf(content_range->value.data, "bytes */%O", r->headers_out.content_length_n) - content_range->value.data; ngx_http_clear_content_length(r); return NGX_HTTP_RANGE_NOT_SATISFIABLE; } static ngx_int_t ngx_http_range_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_http_range_filter_ctx_t *ctx; if (in == NULL) { return ngx_http_next_body_filter(r, in); } ctx = ngx_http_get_module_ctx(r, ngx_http_range_body_filter_module); if (ctx == NULL) { return ngx_http_next_body_filter(r, in); } if (ctx->ranges.nelts == 1) { return ngx_http_range_singlepart_body(r, ctx, in); } /* * multipart ranges are supported only if whole body is in a single buffer */ if (ngx_buf_special(in->buf)) { return ngx_http_next_body_filter(r, in); } if (ngx_http_range_test_overlapped(r, ctx, in) != NGX_OK) { return NGX_ERROR; } return ngx_http_range_multipart_body(r, ctx, in); } static ngx_int_t ngx_http_range_test_overlapped(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in) { off_t start, last; ngx_buf_t *buf; ngx_uint_t i; ngx_http_range_t *range; if (ctx->offset) { goto overlapped; } buf = in->buf; if (!buf->last_buf) { start = ctx->offset; last = ctx->offset + ngx_buf_size(buf); range = ctx->ranges.elts; for (i = 0; i < ctx->ranges.nelts; i++) { if (start > range[i].start || last < range[i].end) { goto overlapped; } } } ctx->offset = ngx_buf_size(buf); return NGX_OK; overlapped: ngx_log_error(NGX_LOG_ALERT, r->connection->log, 0, "range in overlapped buffers"); return NGX_ERROR; } static ngx_int_t ngx_http_range_singlepart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in) { off_t start, last; ngx_int_t rc; ngx_buf_t *buf; ngx_chain_t *out, *cl, *tl, **ll; ngx_http_range_t *range; out = NULL; ll = &out; range = ctx->ranges.elts; for (cl = in; cl; cl = cl->next) { buf = cl->buf; start = ctx->offset; last = ctx->offset + ngx_buf_size(buf); ctx->offset = last; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http range body buf: %O-%O", start, last); if (ngx_buf_special(buf)) { tl = ngx_alloc_chain_link(r->pool); if (tl == NULL) { return NGX_ERROR; } tl->buf = buf; tl->next = NULL; *ll = tl; ll = &tl->next; continue; } if (range->end <= start || range->start >= last) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http range body skip"); if (buf->in_file) { buf->file_pos = buf->file_last; } buf->pos = buf->last; buf->sync = 1; continue; } if (range->start > start) { if (buf->in_file) { buf->file_pos += range->start - start; } if (ngx_buf_in_memory(buf)) { buf->pos += (size_t) (range->start - start); } } if (range->end <= last) { if (buf->in_file) { buf->file_last -= last - range->end; } if (ngx_buf_in_memory(buf)) { buf->last -= (size_t) (last - range->end); } buf->last_buf = (r == r->main) ? 1 : 0; buf->last_in_chain = 1; tl = ngx_alloc_chain_link(r->pool); if (tl == NULL) { return NGX_ERROR; } tl->buf = buf; tl->next = NULL; *ll = tl; ll = &tl->next; continue; } tl = ngx_alloc_chain_link(r->pool); if (tl == NULL) { return NGX_ERROR; } tl->buf = buf; tl->next = NULL; *ll = tl; ll = &tl->next; } if (out == NULL) { return NGX_OK; } rc = ngx_http_next_body_filter(r, out); while (out) { cl = out; out = out->next; ngx_free_chain(r->pool, cl); } return rc; } static ngx_int_t ngx_http_range_multipart_body(ngx_http_request_t *r, ngx_http_range_filter_ctx_t *ctx, ngx_chain_t *in) { ngx_buf_t *b, *buf; ngx_uint_t i; ngx_chain_t *out, *hcl, *rcl, *dcl, **ll; ngx_http_range_t *range; ll = &out; buf = in->buf; range = ctx->ranges.elts; for (i = 0; i < ctx->ranges.nelts; i++) { /* * The boundary header of the range: * CRLF * "--0123456789" CRLF * "Content-Type: image/jpeg" CRLF * "Content-Range: bytes " */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->memory = 1; b->pos = ctx->boundary_header.data; b->last = ctx->boundary_header.data + ctx->boundary_header.len; hcl = ngx_alloc_chain_link(r->pool); if (hcl == NULL) { return NGX_ERROR; } hcl->buf = b; /* "SSSS-EEEE/TTTT" CRLF CRLF */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->temporary = 1; b->pos = range[i].content_range.data; b->last = range[i].content_range.data + range[i].content_range.len; rcl = ngx_alloc_chain_link(r->pool); if (rcl == NULL) { return NGX_ERROR; } rcl->buf = b; /* the range data */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->in_file = buf->in_file; b->temporary = buf->temporary; b->memory = buf->memory; b->mmap = buf->mmap; b->file = buf->file; if (buf->in_file) { b->file_pos = buf->file_pos + range[i].start; b->file_last = buf->file_pos + range[i].end; } if (ngx_buf_in_memory(buf)) { b->pos = buf->pos + (size_t) range[i].start; b->last = buf->pos + (size_t) range[i].end; } dcl = ngx_alloc_chain_link(r->pool); if (dcl == NULL) { return NGX_ERROR; } dcl->buf = b; *ll = hcl; hcl->next = rcl; rcl->next = dcl; ll = &dcl->next; } /* the last boundary CRLF "--0123456789--" CRLF */ b = ngx_calloc_buf(r->pool); if (b == NULL) { return NGX_ERROR; } b->temporary = 1; b->last_buf = 1; b->pos = ngx_pnalloc(r->pool, sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN + sizeof("--" CRLF) - 1); if (b->pos == NULL) { return NGX_ERROR; } b->last = ngx_cpymem(b->pos, ctx->boundary_header.data, sizeof(CRLF "--") - 1 + NGX_ATOMIC_T_LEN); *b->last++ = '-'; *b->last++ = '-'; *b->last++ = CR; *b->last++ = LF; hcl = ngx_alloc_chain_link(r->pool); if (hcl == NULL) { return NGX_ERROR; } hcl->buf = b; hcl->next = NULL; *ll = hcl; return ngx_http_next_body_filter(r, out); } static ngx_int_t ngx_http_range_header_filter_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_range_header_filter; return NGX_OK; } static ngx_int_t ngx_http_range_body_filter_init(ngx_conf_t *cf) { ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_range_body_filter; return NGX_OK; }