Mercurial > hg > nginx
view src/http/modules/ngx_http_slice_filter_module.c @ 7760:83c4622053b0
Upstream: fixed zero size buf alerts on extra data (ticket #2117).
After 7675:9afa45068b8f and 7678:bffcc5af1d72 (1.19.1), during non-buffered
simple proxying, responses with extra data might result in zero size buffers
being generated and "zero size buf" alerts in writer. This bug is similar
to the one with FastCGI proxying fixed in 7689:da8d758aabeb.
In non-buffered mode, normally the filter function is not called if
u->length is already 0, since u->length is checked after each call of
the filter function. There is a case when this can happen though: if
the response length is 0, and there are pre-read response body data left
after reading response headers. As such, a check for u->length is needed
at the start of non-buffered filter functions, similar to the one
for p->length present in buffered filter functions.
Appropriate checks added to the existing non-buffered copy filters
in the upstream (used by scgi and uwsgi proxying) and proxy modules.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 12 Jan 2021 16:59:31 +0300 |
parents | 32a343635b50 |
children |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { size_t size; } ngx_http_slice_loc_conf_t; typedef struct { off_t start; off_t end; ngx_str_t range; ngx_str_t etag; unsigned last:1; unsigned active:1; ngx_http_request_t *sr; } ngx_http_slice_ctx_t; typedef struct { off_t start; off_t end; off_t complete_length; } ngx_http_slice_content_range_t; static ngx_int_t ngx_http_slice_header_filter(ngx_http_request_t *r); static ngx_int_t ngx_http_slice_body_filter(ngx_http_request_t *r, ngx_chain_t *in); static ngx_int_t ngx_http_slice_parse_content_range(ngx_http_request_t *r, ngx_http_slice_content_range_t *cr); static ngx_int_t ngx_http_slice_range_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data); static off_t ngx_http_slice_get_start(ngx_http_request_t *r); static void *ngx_http_slice_create_loc_conf(ngx_conf_t *cf); static char *ngx_http_slice_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_slice_add_variables(ngx_conf_t *cf); static ngx_int_t ngx_http_slice_init(ngx_conf_t *cf); static ngx_command_t ngx_http_slice_filter_commands[] = { { ngx_string("slice"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_TAKE1, ngx_conf_set_size_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_slice_loc_conf_t, size), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_slice_filter_module_ctx = { ngx_http_slice_add_variables, /* preconfiguration */ ngx_http_slice_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_slice_create_loc_conf, /* create location configuration */ ngx_http_slice_merge_loc_conf /* merge location configuration */ }; ngx_module_t ngx_http_slice_filter_module = { NGX_MODULE_V1, &ngx_http_slice_filter_module_ctx, /* module context */ ngx_http_slice_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_str_t ngx_http_slice_range_name = ngx_string("slice_range"); 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_slice_header_filter(ngx_http_request_t *r) { off_t end; ngx_int_t rc; ngx_table_elt_t *h; ngx_http_slice_ctx_t *ctx; ngx_http_slice_loc_conf_t *slcf; ngx_http_slice_content_range_t cr; ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module); if (ctx == NULL) { return ngx_http_next_header_filter(r); } if (r->headers_out.status != NGX_HTTP_PARTIAL_CONTENT) { if (r == r->main) { ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module); return ngx_http_next_header_filter(r); } ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "unexpected status code %ui in slice response", r->headers_out.status); return NGX_ERROR; } h = r->headers_out.etag; if (ctx->etag.len) { if (h == NULL || h->value.len != ctx->etag.len || ngx_strncmp(h->value.data, ctx->etag.data, ctx->etag.len) != 0) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "etag mismatch in slice response"); return NGX_ERROR; } } if (h) { ctx->etag = h->value; } if (ngx_http_slice_parse_content_range(r, &cr) != NGX_OK) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "invalid range in slice response"); return NGX_ERROR; } if (cr.complete_length == -1) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "no complete length in slice response"); return NGX_ERROR; } ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http slice response range: %O-%O/%O", cr.start, cr.end, cr.complete_length); slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module); end = ngx_min(cr.start + (off_t) slcf->size, cr.complete_length); if (cr.start != ctx->start || cr.end != end) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "unexpected range in slice response: %O-%O", cr.start, cr.end); return NGX_ERROR; } ctx->start = end; ctx->active = 1; r->headers_out.status = NGX_HTTP_OK; r->headers_out.status_line.len = 0; r->headers_out.content_length_n = cr.complete_length; r->headers_out.content_offset = cr.start; r->headers_out.content_range->hash = 0; r->headers_out.content_range = NULL; if (r->headers_out.accept_ranges) { r->headers_out.accept_ranges->hash = 0; r->headers_out.accept_ranges = NULL; } r->allow_ranges = 1; r->subrequest_ranges = 1; r->single_range = 1; rc = ngx_http_next_header_filter(r); if (r != r->main) { return rc; } r->preserve_body = 1; if (r->headers_out.status == NGX_HTTP_PARTIAL_CONTENT) { if (ctx->start + (off_t) slcf->size <= r->headers_out.content_offset) { ctx->start = slcf->size * (r->headers_out.content_offset / slcf->size); } ctx->end = r->headers_out.content_offset + r->headers_out.content_length_n; } else { ctx->end = cr.complete_length; } return rc; } static ngx_int_t ngx_http_slice_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_int_t rc; ngx_chain_t *cl; ngx_http_slice_ctx_t *ctx; ngx_http_slice_loc_conf_t *slcf; ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module); if (ctx == NULL || r != r->main) { return ngx_http_next_body_filter(r, in); } for (cl = in; cl; cl = cl->next) { if (cl->buf->last_buf) { cl->buf->last_buf = 0; cl->buf->last_in_chain = 1; cl->buf->sync = 1; ctx->last = 1; } } rc = ngx_http_next_body_filter(r, in); if (rc == NGX_ERROR || !ctx->last) { return rc; } if (ctx->sr && !ctx->sr->done) { return rc; } if (!ctx->active) { ngx_log_error(NGX_LOG_ERR, r->connection->log, 0, "missing slice response"); return NGX_ERROR; } if (ctx->start >= ctx->end) { ngx_http_set_ctx(r, NULL, ngx_http_slice_filter_module); ngx_http_send_special(r, NGX_HTTP_LAST); return rc; } if (r->buffered) { return rc; } if (ngx_http_subrequest(r, &r->uri, &r->args, &ctx->sr, NULL, NGX_HTTP_SUBREQUEST_CLONE) != NGX_OK) { return NGX_ERROR; } ngx_http_set_ctx(ctx->sr, ctx, ngx_http_slice_filter_module); slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module); ctx->range.len = ngx_sprintf(ctx->range.data, "bytes=%O-%O", ctx->start, ctx->start + (off_t) slcf->size - 1) - ctx->range.data; ctx->active = 0; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "http slice subrequest: \"%V\"", &ctx->range); return rc; } static ngx_int_t ngx_http_slice_parse_content_range(ngx_http_request_t *r, ngx_http_slice_content_range_t *cr) { off_t start, end, complete_length, cutoff, cutlim; u_char *p; ngx_table_elt_t *h; h = r->headers_out.content_range; if (h == NULL || h->value.len < 7 || ngx_strncmp(h->value.data, "bytes ", 6) != 0) { return NGX_ERROR; } p = h->value.data + 6; cutoff = NGX_MAX_OFF_T_VALUE / 10; cutlim = NGX_MAX_OFF_T_VALUE % 10; start = 0; end = 0; complete_length = 0; while (*p == ' ') { p++; } if (*p < '0' || *p > '9') { return NGX_ERROR; } while (*p >= '0' && *p <= '9') { if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } start = start * 10 + (*p++ - '0'); } while (*p == ' ') { p++; } if (*p++ != '-') { return NGX_ERROR; } while (*p == ' ') { p++; } if (*p < '0' || *p > '9') { return NGX_ERROR; } while (*p >= '0' && *p <= '9') { if (end >= cutoff && (end > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } end = end * 10 + (*p++ - '0'); } end++; while (*p == ' ') { p++; } if (*p++ != '/') { return NGX_ERROR; } while (*p == ' ') { p++; } if (*p != '*') { if (*p < '0' || *p > '9') { return NGX_ERROR; } while (*p >= '0' && *p <= '9') { if (complete_length >= cutoff && (complete_length > cutoff || *p - '0' > cutlim)) { return NGX_ERROR; } complete_length = complete_length * 10 + (*p++ - '0'); } } else { complete_length = -1; p++; } while (*p == ' ') { p++; } if (*p != '\0') { return NGX_ERROR; } cr->start = start; cr->end = end; cr->complete_length = complete_length; return NGX_OK; } static ngx_int_t ngx_http_slice_range_variable(ngx_http_request_t *r, ngx_http_variable_value_t *v, uintptr_t data) { u_char *p; ngx_http_slice_ctx_t *ctx; ngx_http_slice_loc_conf_t *slcf; ctx = ngx_http_get_module_ctx(r, ngx_http_slice_filter_module); if (ctx == NULL) { if (r != r->main || r->headers_out.status) { v->not_found = 1; return NGX_OK; } slcf = ngx_http_get_module_loc_conf(r, ngx_http_slice_filter_module); if (slcf->size == 0) { v->not_found = 1; return NGX_OK; } ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_slice_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } ngx_http_set_ctx(r, ctx, ngx_http_slice_filter_module); p = ngx_pnalloc(r->pool, sizeof("bytes=-") - 1 + 2 * NGX_OFF_T_LEN); if (p == NULL) { return NGX_ERROR; } ctx->start = slcf->size * (ngx_http_slice_get_start(r) / slcf->size); ctx->range.data = p; ctx->range.len = ngx_sprintf(p, "bytes=%O-%O", ctx->start, ctx->start + (off_t) slcf->size - 1) - p; } v->data = ctx->range.data; v->valid = 1; v->not_found = 0; v->no_cacheable = 1; v->len = ctx->range.len; return NGX_OK; } static off_t ngx_http_slice_get_start(ngx_http_request_t *r) { off_t start, cutoff, cutlim; u_char *p; ngx_table_elt_t *h; if (r->headers_in.if_range) { return 0; } h = r->headers_in.range; if (h == NULL || h->value.len < 7 || ngx_strncasecmp(h->value.data, (u_char *) "bytes=", 6) != 0) { return 0; } p = h->value.data + 6; if (ngx_strchr(p, ',')) { return 0; } while (*p == ' ') { p++; } if (*p == '-') { return 0; } cutoff = NGX_MAX_OFF_T_VALUE / 10; cutlim = NGX_MAX_OFF_T_VALUE % 10; start = 0; while (*p >= '0' && *p <= '9') { if (start >= cutoff && (start > cutoff || *p - '0' > cutlim)) { return 0; } start = start * 10 + (*p++ - '0'); } return start; } static void * ngx_http_slice_create_loc_conf(ngx_conf_t *cf) { ngx_http_slice_loc_conf_t *slcf; slcf = ngx_palloc(cf->pool, sizeof(ngx_http_slice_loc_conf_t)); if (slcf == NULL) { return NULL; } slcf->size = NGX_CONF_UNSET_SIZE; return slcf; } static char * ngx_http_slice_merge_loc_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_slice_loc_conf_t *prev = parent; ngx_http_slice_loc_conf_t *conf = child; ngx_conf_merge_size_value(conf->size, prev->size, 0); return NGX_CONF_OK; } static ngx_int_t ngx_http_slice_add_variables(ngx_conf_t *cf) { ngx_http_variable_t *var; var = ngx_http_add_variable(cf, &ngx_http_slice_range_name, 0); if (var == NULL) { return NGX_ERROR; } var->get_handler = ngx_http_slice_range_variable; return NGX_OK; } static ngx_int_t ngx_http_slice_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_slice_header_filter; ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_slice_body_filter; return NGX_OK; }