Using Nginx subrequest to enable interaction with multiple backend servers

/*

 * Using Nginx subrequest to achieve interaction with multiple backend servers * Nginx version:1.2.2 * Copyright (C) eling * email:luxuejun12@gmai.com * * /extern "C" {#include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h>}//Nginx header Files should go before other, because they define 64-bit off_t #define LAUTH_EXT_CMD_ARGS_NUM 2 typedef struct {NGX	_uint_t N;
2 ngx_array_t *uris;

} ngx_http_lauth_ext_conf_t;
    typedef struct {ngx_uint_t done;
	ngx_uint_t status;
	
    ngx_str_t *content;
ngx_http_request_t *SR;

} ngx_http_lauth_ext_subrequest;
	typedef struct {ngx_uint_t i;	
ngx_array_t *subrequests;

} ngx_http_lauth_ext_ctx_t;
Static ngx_int_t Ngx_http_lauth_ext_handler (ngx_http_request_t *r);

Static ngx_int_t Ngx_http_lauth_ext_done (ngx_http_request_t *r, void *data, ngx_int_t RC);

static void *ngx_http_lauth_ext_create_conf (ngx_conf_t *cf); static Char *ngx_http_lauth_ext (ngx_conf_t *CF, ngx_command_t *cmd, void *conf); Static ngx_command_t ngx_http_lauth_ext_commands[] = {{ngx_string ("Lauth_ext"), ngx_http_loc_conf| Ngx_conf_take2, Ngx_http_lauth_ext, Ngx_http_loc_conf_offset, 0, NULL}, Ngx_null_command}


;  Static ngx_http_module_t Ngx_http_lauth_ext_module_ctx = {NULL,/* preconfiguration */NULL,/* postconfiguration */NULL,/* Create main Configur                                  ation */NULL,/* INIT main configuration */null, /* Create server Configuration */NULL,/* Merge server configuration */NGX  _http_lauth_ext_create_conf,/* Create location Configuration */NULL/* Merge location configuration


*/
}; ngx_module_t Ngx_http_lauth_ext_module = {NGX_MODULE_V1, &ngx_http_lauth_exT_MODULE_CTX,/* Module context */Ngx_http_lauth_ext_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_int_t Ngx_http_lauth_ext_handler (ngx_http_request_t *r) {ngx_log_error (Ngx_log_debug, r->connection-

	>log, 0, "Lauth_ext request handler, Uri:%v args:%v", &r->uri, &r->args);
    ngx_int_t RC;
	ngx_http_lauth_ext_conf_t *LACF;
	ngx_str_t *uri;
	
	ngx_str_t *args;	
	ngx_http_lauth_ext_ctx_t *ctx; Ngx_http_lauth_ext_subrequest *lasr;	
	
    ngx_http_post_subrequest_t *ps; 	
	
    LACF = (ngx_http_lauth_ext_conf_t *) ngx_http_get_module_loc_conf (R, Ngx_http_lauth_ext_module);

CTX = (ngx_http_lauth_ext_ctx_t *) Ngx_http_get_module_ctx (R, Ngx_http_lauth_ext_module);

    args = &r->args;  if (ctx! = NULL) {ngx_http_lauth_ext_subrequest* Lasr = (ngx_http_lauth_ext_subrequest*) Ctx->subrequests->elts +
		
        (ctx->i-1); if (ctx->i = = Lauth_ext_cmd_args_num) {if (Lasr->status = = ngx_http_internal_server_error) {Ngx_http_finalize_r
				Equest (R, Ngx_http_internal_server_error);
			return NGX_OK;
				} else if (lasr->status! = NGX_HTTP_OK) {r->headers_out.status = lasr->status;

				R->header_only = 1;//???
				rc = Ngx_http_send_header (r);
				Ngx_http_finalize_request (R, RC);
			return NGX_OK;			
			} r->headers_out.status = lasr->status;			
			
			R->headers_out.content_length_n = lasr->content->len; rc = Ngx_http_Send_header (R);
				if (rc = = Ngx_error | | rc > NGX_OK | | r->header_only) {ngx_http_finalize_request (r, RC);
    		return NGX_OK;
			} ngx_chain_t out;

			ngx_buf_t b;
			Ngx_memzero (&b, sizeof (ngx_buf_t));
			B.temporary = 1;	B.last_buf = 1;
			
			//???
			B.pos = lasr->content->data;
			B.last = B.pos + lasr->content->len;
			B.start = B.pos;			
			
			B.end = B.last;
			Out.buf = &b;

			Out.next = NULL;
    		rc = Ngx_http_output_filter (R, &out);
			Ngx_http_finalize_request (R, RC);
		return NGX_OK; } if (lasr->status = = Ngx_http_internal_server_error) {ngx_http_finalize_request (R, Ngx_http_internal_server_erro
			R);
		return NGX_OK;
			} else if (lasr->status! = NGX_HTTP_OK) {r->headers_out.status = lasr->status;

			R->header_only = 1;//???
			rc = Ngx_http_send_header (r);
			Ngx_http_finalize_request (R, RC);
		return NGX_OK;

		}//args = lasr->content; args = (ngx_str_t *) Ngx_palloc (R->pooL, sizeof (ngx_str_t));
			if (args = = NULL) {ngx_http_finalize_request (R, Ngx_http_internal_server_error);
		return NGX_OK;
		} Args->len = R->args.len + 1 + lasr->content->len;
		Args->data = (U_char *) Ngx_palloc (R->pool, Args->len);
			if (Args->data = = NULL) {ngx_http_finalize_request (R, Ngx_http_internal_server_error);
		return NGX_OK;
		} ngx_memcpy (Args->data, R->args.data, R->args.len);
		Args->data[r->args.len] = ' & ';
ngx_memcpy (args->data + r->args.len + 1, lasr->content->data, Lasr->content->len); 
		#if 0/*for Test *uri dont contain ' \ r ', ... */U_char *p = Lasr->content->data + lasr->content->len;			
		while (*--p = = ' \ n ') {args->len--;
			} while (*--p = = ' \ n ') {ngx_http_finalize_request (R, Ngx_http_internal_server_error);
		return NGX_OK;
    } #endif goto Subrequest;
	} else{args = &r->args; } CTX = (ngx_http_lauth_ext_ctx_t *) Ngx_pcalloc (r->Pool, sizeof (ngx_http_lauth_ext_ctx_t));
    if (CTX = = NULL) {return ngx_error; } ctx->subrequests = Ngx_array_create (R->pool, Lauth_ext_cmd_args_num, sizeof (ngx_http_lauth_ext_subrequest))
	;
    if (ctx->subrequests = = NULL) {return ngx_error;

} ngx_http_set_ctx (R, CTX, Ngx_http_lauth_ext_module);
	Subrequest:uri = (ngx_str_t *) Lacf->uris->elts + ctx->i;
	
	Ctx->i + +;
	LASR = (Ngx_http_lauth_ext_subrequest *) Ngx_array_push (ctx->subrequests);

    Ngx_memzero (LASR, sizeof (ngx_http_lauth_ext_subrequest));
    PS = (ngx_http_post_subrequest_t *) ngx_palloc (r->pool, sizeof (ngx_http_post_subrequest_t));
    if (PS = = NULL) {return ngx_error;
    } Ps->handler = Ngx_http_lauth_ext_done;	 

    Ps->data = CTX; if (Ngx_http_subrequest (R, Uri, args, &AMP;LASR-&GT;SR, PS, ngx_http_subrequest_in_memory/* |
	ngx_http_subrequest_waited*/)! = NGX_OK) {return ngx_error; } ngx_log_error (Ngx_log_debug, R->connection-> log, 0, "Lauth_ext request handler, Subrequest uri:%v args:%v", Uri, args);
return ngx_again; } static ngx_int_t Ngx_http_lauth_ext_done (ngx_http_request_t *r, void *data, ngx_int_t rc) {NGX_HTTP_LAUTH_EXT_CT  

	x_t *ctx = (ngx_http_lauth_ext_ctx_t *) data;

	ngx_http_lauth_ext_subrequest* LASR = (ngx_http_lauth_ext_subrequest*) Ctx->subrequests->elts + (ctx->i-1);
	Lasr->done = 1;

	Lasr->status = r->headers_out.status;  if (Lasr->status = = NGX_HTTP_OK) {if (R->upstream = = NULL) {ngx_log_error (Ngx_log_err, R->connection->log, 
                   0, "Lauth_ext subrequest done, Subrequest does not support upstream, Uri:%v Args:%v",

			&r->uri, &r->args);
			Lasr->status = Ngx_http_internal_server_error;
		Goto end;
			} if (lasr->content = = NULL) {lasr->content = (ngx_str_t *) ngx_palloc (r->pool, sizeof (ngx_str_t)); if (lasr->content = = NULL) {lasr->status = Ngx_htTp_internal_server_error;
			Goto end;
		}} Lasr->content->len = r->headers_out.content_length_n;
		Lasr->content->data = (U_char *) Ngx_palloc (R->pool, Lasr->content->len);
			if (Lasr->content->data = = NULL) {lasr->status = Ngx_http_internal_server_error;
		Goto end;

		} ngx_memcpy (Lasr->content->data, R->upstream->buffer.pos, Lasr->content->len);
	Goto end; } end:if (Lasr->content! = NULL) {ngx_log_error (ngx_log_debug, R->connection->log, 0, "Lau Th_ext subrequest Done, uri:%v args:%v rc:%i status:%i content:%v ", &r->uri, &r->args, R
	C, Lasr->status, lasr->content);  } else{Ngx_log_error (Ngx_log_debug, R->connection->log, 0, "Lauth_ext subrequest done, uri:%v
	Args:%v rc:%i status:%i ", &r->uri, &r->args, RC, lasr->status); } R->parent->write_event_handler = (ngx_http_evenT_HANDLER_PT) Ngx_http_lauth_ext_handler;
return RC;

    } static void * ngx_http_lauth_ext_create_conf (ngx_conf_t *cf) {ngx_http_lauth_ext_conf_t *conf;
    conf = (ngx_http_lauth_ext_conf_t *) ngx_pcalloc (cf->pool, sizeof (ngx_http_lauth_ext_conf_t));
    if (conf = = null) {return null;
	} conf->n = Lauth_ext_cmd_args_num;
	Conf->uris = Ngx_array_create (Cf->pool, Lauth_ext_cmd_args_num, sizeof (ngx_str_t));
	if (Conf->uris = = NULL) {return ngx_conf_error;
} return conf;  } Static char * Ngx_http_lauth_ext (ngx_conf_t *cf, ngx_command_t *cmd, void *conf) {ngx_http_lauth_ext_conf_t *LACF
	= (ngx_http_lauth_ext_conf_t *) conf;

    ngx_http_core_loc_conf_t *CLCF;
    ngx_str_t *uri, *value;	

	Value = (ngx_str_t *) cf->args->elts;
		for (ngx_uint_t i = 1; I <= lacf->n; i++) {uri = (ngx_str_t *) Ngx_array_push (Lacf->uris);
		
		*uri = Value[i]; Ngx_log_error (Ngx_log_debug, Cf->log, 0, "Lauth_ext args:%V", URI);
	} CLCF = (ngx_http_core_loc_conf_t *) ngx_http_conf_get_module_loc_conf (cf, Ngx_http_core_module);

    Clcf->handler = Ngx_http_lauth_ext_handler;
return NGX_CONF_OK;
 }