diff options
Diffstat (limited to 'app/nginx/src/http/modules/ngx_http_not_modified_filter_module.c')
| -rw-r--r-- | app/nginx/src/http/modules/ngx_http_not_modified_filter_module.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/app/nginx/src/http/modules/ngx_http_not_modified_filter_module.c b/app/nginx/src/http/modules/ngx_http_not_modified_filter_module.c new file mode 100644 index 0000000..032ba96 --- /dev/null +++ b/app/nginx/src/http/modules/ngx_http_not_modified_filter_module.c @@ -0,0 +1,266 @@ + +/* + * Copyright (C) Igor Sysoev + * Copyright (C) Nginx, Inc. + */ + + +#include <ngx_config.h> +#include <ngx_core.h> +#include <ngx_http.h> + + +static ngx_uint_t ngx_http_test_if_unmodified(ngx_http_request_t *r); +static ngx_uint_t ngx_http_test_if_modified(ngx_http_request_t *r); +static ngx_uint_t ngx_http_test_if_match(ngx_http_request_t *r, + ngx_table_elt_t *header, ngx_uint_t weak); +static ngx_int_t ngx_http_not_modified_filter_init(ngx_conf_t *cf); + + +static ngx_http_module_t ngx_http_not_modified_filter_module_ctx = { + NULL, /* preconfiguration */ + ngx_http_not_modified_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_not_modified_filter_module = { + NGX_MODULE_V1, + &ngx_http_not_modified_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_int_t +ngx_http_not_modified_header_filter(ngx_http_request_t *r) +{ + if (r->headers_out.status != NGX_HTTP_OK + || r != r->main + || r->disable_not_modified) + { + return ngx_http_next_header_filter(r); + } + + if (r->headers_in.if_unmodified_since + && !ngx_http_test_if_unmodified(r)) + { + return ngx_http_filter_finalize_request(r, NULL, + NGX_HTTP_PRECONDITION_FAILED); + } + + if (r->headers_in.if_match + && !ngx_http_test_if_match(r, r->headers_in.if_match, 0)) + { + return ngx_http_filter_finalize_request(r, NULL, + NGX_HTTP_PRECONDITION_FAILED); + } + + if (r->headers_in.if_modified_since || r->headers_in.if_none_match) { + + if (r->headers_in.if_modified_since + && ngx_http_test_if_modified(r)) + { + return ngx_http_next_header_filter(r); + } + + if (r->headers_in.if_none_match + && !ngx_http_test_if_match(r, r->headers_in.if_none_match, 1)) + { + return ngx_http_next_header_filter(r); + } + + /* not modified */ + + r->headers_out.status = NGX_HTTP_NOT_MODIFIED; + r->headers_out.status_line.len = 0; + r->headers_out.content_type.len = 0; + ngx_http_clear_content_length(r); + ngx_http_clear_accept_ranges(r); + + if (r->headers_out.content_encoding) { + r->headers_out.content_encoding->hash = 0; + r->headers_out.content_encoding = NULL; + } + + return ngx_http_next_header_filter(r); + } + + return ngx_http_next_header_filter(r); +} + + +static ngx_uint_t +ngx_http_test_if_unmodified(ngx_http_request_t *r) +{ + time_t iums; + + if (r->headers_out.last_modified_time == (time_t) -1) { + return 0; + } + + iums = ngx_parse_http_time(r->headers_in.if_unmodified_since->value.data, + r->headers_in.if_unmodified_since->value.len); + + ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, + "http iums:%T lm:%T", iums, r->headers_out.last_modified_time); + + if (iums >= r->headers_out.last_modified_time) { + return 1; + } + + return 0; +} + + +static ngx_uint_t +ngx_http_test_if_modified(ngx_http_request_t *r) +{ + time_t ims; + ngx_http_core_loc_conf_t *clcf; + + if (r->headers_out.last_modified_time == (time_t) -1) { + return 1; + } + + clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module); + + if (clcf->if_modified_since == NGX_HTTP_IMS_OFF) { + return 1; + } + + ims = ngx_parse_http_time(r->headers_in.if_modified_since->value.data, + r->headers_in.if_modified_since->value.len); + + ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, + "http ims:%T lm:%T", ims, r->headers_out.last_modified_time); + + if (ims == r->headers_out.last_modified_time) { + return 0; + } + + if (clcf->if_modified_since == NGX_HTTP_IMS_EXACT + || ims < r->headers_out.last_modified_time) + { + return 1; + } + + return 0; +} + + +static ngx_uint_t +ngx_http_test_if_match(ngx_http_request_t *r, ngx_table_elt_t *header, + ngx_uint_t weak) +{ + u_char *start, *end, ch; + ngx_str_t etag, *list; + + list = &header->value; + + if (list->len == 1 && list->data[0] == '*') { + return 1; + } + + if (r->headers_out.etag == NULL) { + return 0; + } + + etag = r->headers_out.etag->value; + + ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, + "http im:\"%V\" etag:%V", list, &etag); + + if (weak + && etag.len > 2 + && etag.data[0] == 'W' + && etag.data[1] == '/') + { + etag.len -= 2; + etag.data += 2; + } + + start = list->data; + end = list->data + list->len; + + while (start < end) { + + if (weak + && end - start > 2 + && start[0] == 'W' + && start[1] == '/') + { + start += 2; + } + + if (etag.len > (size_t) (end - start)) { + return 0; + } + + if (ngx_strncmp(start, etag.data, etag.len) != 0) { + goto skip; + } + + start += etag.len; + + while (start < end) { + ch = *start; + + if (ch == ' ' || ch == '\t') { + start++; + continue; + } + + break; + } + + if (start == end || *start == ',') { + return 1; + } + + skip: + + while (start < end && *start != ',') { start++; } + while (start < end) { + ch = *start; + + if (ch == ' ' || ch == '\t' || ch == ',') { + start++; + continue; + } + + break; + } + } + + return 0; +} + + +static ngx_int_t +ngx_http_not_modified_filter_init(ngx_conf_t *cf) +{ + ngx_http_next_header_filter = ngx_http_top_header_filter; + ngx_http_top_header_filter = ngx_http_not_modified_header_filter; + + return NGX_OK; +} |