Mercurial > hg > ngx_http_compose_filter_module
view ngx_http_compose_filter_module.c @ 1:ba5471a3c988
First working code, still in progress.
Body filtering isn't complete. Notably, it probably will fail with
complex body replies and with non-static subrequests.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Tue, 15 Jul 2008 05:38:48 +0400 |
parents | 6535d94ae07d |
children | ed63d0bd4d14 |
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/* * Copyright (C) Maxim Dounin */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_flag_t enable; } ngx_http_compose_conf_t; typedef struct { ngx_uint_t done; ngx_array_t parts; } ngx_http_compose_ctx_t; static void *ngx_http_compose_create_conf(ngx_conf_t *cf); static char *ngx_http_compose_merge_conf(ngx_conf_t *cf, void *parent, void *child); static ngx_int_t ngx_http_compose_init(ngx_conf_t *cf); static ngx_int_t ngx_http_compose_body_init(ngx_conf_t *cf); static ngx_command_t ngx_http_compose_commands[] = { { ngx_string("compose"), NGX_HTTP_MAIN_CONF|NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG, ngx_conf_set_flag_slot, NGX_HTTP_LOC_CONF_OFFSET, offsetof(ngx_http_compose_conf_t, enable), NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_compose_module_ctx = { NULL, /* preconfiguration */ ngx_http_compose_init, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ ngx_http_compose_create_conf, /* create location configuration */ ngx_http_compose_merge_conf /* merge location configuration */ }; ngx_module_t ngx_http_compose_filter_module = { NGX_MODULE_V1, &ngx_http_compose_module_ctx, /* module context */ ngx_http_compose_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_module_t ngx_http_compose_body_module_ctx = { NULL, /* preconfiguration */ ngx_http_compose_body_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_compose_body_filter_module = { NGX_MODULE_V1, &ngx_http_compose_body_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_compose_header_filter(ngx_http_request_t *r) { ngx_uint_t i; ngx_str_t *uri; ngx_list_part_t *part; ngx_table_elt_t *header; ngx_http_compose_conf_t *conf; ngx_http_compose_ctx_t *ctx; conf = ngx_http_get_module_loc_conf(r, ngx_http_compose_filter_module); if (!conf->enable) { return ngx_http_next_header_filter(r); } ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose header filter"); /* create context */ ctx = ngx_pcalloc(r->pool, sizeof(ngx_http_compose_ctx_t)); if (ctx == NULL) { return NGX_ERROR; } if (ngx_array_init(&ctx->parts, r->pool, 1, sizeof(ngx_str_t)) == NGX_ERROR) { return NGX_ERROR; } /* * Collect all X-Compose headers (or combined one?), store in context * for our body filter to make actual subrequests. Hide them from the * response. */ part = &r->headers_out.headers.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; } if (header[i].key.len == sizeof("X-Compose-Length") - 1 && ngx_strncasecmp(header[i].key.data, "X-Compose-Length", sizeof("X-Compose-Length") - 1) == 0) { ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose body filter: bingo, %V, %V", &header[i].key, &header[i].value); header[i].hash = 0; r->headers_out.content_length_n = ngx_atoof(header[i].value.data, header[i].value.len); if (r->headers_out.content_length) { r->headers_out.content_length->hash = 0; r->headers_out.content_length = NULL; } } if (header[i].key.len == sizeof("X-Compose") - 1 && ngx_strncasecmp(header[i].key.data, "X-Compose", sizeof("X-Compose") - 1) == 0) { ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose body filter: bingo, %V, %V", &header[i].key, &header[i].value); header[i].hash = 0; /* * XXX multiple headers with the same name must be combinable, * see RFC 2616 4.2 Message Headers */ uri = ngx_array_push(&ctx->parts); if (uri == NULL) { return NGX_ERROR; } *uri = header[i].value; } } ngx_http_set_ctx(r, ctx, ngx_http_compose_filter_module); return ngx_http_next_header_filter(r); } static ngx_int_t ngx_http_compose_body_filter(ngx_http_request_t *r, ngx_chain_t *in) { ngx_str_t *uri, args; ngx_int_t rc; ngx_uint_t i, flags; ngx_http_request_t *sr; ngx_http_compose_ctx_t *ctx; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose body filter"); ctx = ngx_http_get_module_ctx(r, ngx_http_compose_filter_module); if (ctx == NULL) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose body filter: no ctx"); return ngx_http_next_body_filter(r, in); } if (ctx->done) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose body filter: done"); /* XXX wrong: should skip data instead */ return ngx_http_next_body_filter(r, in); } ctx->done = 1; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "compose body filter, doing work"); /* * Ignore body that comes to us, replace it with subrequests. */ uri = ctx->parts.elts; for (i = 0; i < ctx->parts.nelts; i++) { args.len = 0; args.data = NULL; flags = 0; if (ngx_http_parse_unsafe_uri(r, &uri[i], &args, &flags) != NGX_OK) { return NGX_ERROR; } rc = ngx_http_subrequest(r, &uri[i], &args, &sr, NULL, flags); if (rc == NGX_ERROR || rc == NGX_DONE) { return rc; } } for ( ; in; in = in->next) { in->buf->pos = in->buf->last; in->buf->last_buf = 0; } /* * XXX: what to do if non-static data? probably we should use post * subrequest hook instead */ return ngx_http_send_special(r, NGX_HTTP_LAST); } static void * ngx_http_compose_create_conf(ngx_conf_t *cf) { ngx_http_compose_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_compose_conf_t)); if (conf == NULL) { return NGX_CONF_ERROR; } conf->enable = NGX_CONF_UNSET; return conf; } static char * ngx_http_compose_merge_conf(ngx_conf_t *cf, void *parent, void *child) { ngx_http_compose_conf_t *prev = parent; ngx_http_compose_conf_t *conf = child; ngx_conf_merge_value(conf->enable, prev->enable, 0); return NGX_CONF_OK; } static ngx_int_t ngx_http_compose_init(ngx_conf_t *cf) { ngx_http_next_header_filter = ngx_http_top_header_filter; ngx_http_top_header_filter = ngx_http_compose_header_filter; return NGX_OK; } static ngx_int_t ngx_http_compose_body_init(ngx_conf_t *cf) { ngx_http_next_body_filter = ngx_http_top_body_filter; ngx_http_top_body_filter = ngx_http_compose_body_filter; return NGX_OK; }