http.c

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Author : Nick Mathewson
Date : 2007-11-07 06:01:57
Hash : f74e7258
Message : r16501@catbus: nickm | 2007-11-07 01:00:31 -0500 This is one of those patches which will either make matters far simpler after the bugs shake out, or will get reverted pretty quick once we realize that it is a stupid idea. We now post-process the config.h file into a new event-config.h file, whose macros are prefixed with _EVENT_ and which is thus safe for headers to include. Using this, we can define replacement timeval manipulation functions in evutil.h, and use them uniformly through our code. We can also detect which headers are needful in event.h, and include them as required. This is also the perfect time to remove the long-deprecated acconfig.h file, so that autoheader no longer warns. Should resolve the following issues: [ 1826530 ] Header files should have access to autoconf output. [ 1826545 ] acconfig.h is deprecated. [ 1826564 ] On some platforms, event.h can't be included alone. svn:r492
http.c
/*
 * Copyright (c) 2002-2006 Niels Provos <provos@citi.umich.edu>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <sys/param.h>
#include <sys/types.h>

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYS_IOCCOM_H
#include <sys/ioccom.h>
#endif

#ifndef WIN32
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/wait.h>
#endif

#include <sys/queue.h>

#ifndef WIN32
#include <netinet/in.h>
#include <netdb.h>
#endif

#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifndef WIN32
#include <syslog.h>
#endif
#include <signal.h>
#include <time.h>
#include <unistd.h>
#include <fcntl.h>

#undef timeout_pending
#undef timeout_initialized

#include "strlcpy-internal.h"
#include "event.h"
#include "evhttp.h"
#include "evutil.h"
#include "log.h"
#include "http-internal.h"

#ifndef HAVE_GETADDRINFO
struct addrinfo {
	int ai_family;
	int ai_socktype;
	int ai_protocol;
	size_t ai_addrlen;
	struct sockaddr *ai_addr;
	struct addrinfo *ai_next;
};
static int
fake_getaddrinfo(const char *hostname, struct addrinfo *ai)
{
	struct hostent *he = NULL;
	struct sockaddr_in *sa;
	if (hostname) {
		he = gethostbyname(hostname);
		if (!he)
			return (-1);
	}
	ai->ai_family = he ? he->h_addrtype : AF_INET;
	ai->ai_socktype = SOCK_STREAM;
	ai->ai_protocol = 0;
	ai->ai_addrlen = sizeof(struct sockaddr_in);
	if (NULL == (ai->ai_addr = malloc(ai->ai_addrlen)))
		return (-1);
	sa = (struct sockaddr_in*)ai->ai_addr;
	memset(sa, 0, ai->ai_addrlen);
	if (he) {
		sa->sin_family = he->h_addrtype;
		memcpy(&sa->sin_addr, he->h_addr_list[0], he->h_length);
	} else {
		sa->sin_family = AF_INET;
		sa->sin_addr.s_addr = INADDR_ANY;
	}
	ai->ai_next = NULL;
	return (0);
}
static void
fake_freeaddrinfo(struct addrinfo *ai)
{
	free(ai->ai_addr);
}
#endif

#ifndef MIN
#define MIN(a,b) (((a)<(b))?(a):(b))
#endif

/* wrapper for setting the base from the http server */
#define EVHTTP_BASE_SET(x, y) do { \
	if ((x)->base != NULL) event_base_set((x)->base, y);	\
} while (0) 

extern int debug;

static int socket_connect(int fd, const char *address, unsigned short port);
static int bind_socket_ai(struct addrinfo *);
static int bind_socket(const char *, u_short);
static void name_from_addr(struct sockaddr *, socklen_t, char **, char **);
static int evhttp_associate_new_request_with_connection(
	struct evhttp_connection *evcon);
static void evhttp_connection_start_detectclose(
	struct evhttp_connection *evcon);
static void evhttp_connection_stop_detectclose(
	struct evhttp_connection *evcon);
static void evhttp_request_dispatch(struct evhttp_connection* evcon);

void evhttp_read(int, short, void *);
void evhttp_write(int, short, void *);

#ifndef HAVE_STRSEP
/* strsep replacement for platforms that lack it.  Only works if
 * del is one character long. */
static char *
strsep(char **s, const char *del)
{
	char *d, *tok;
	assert(strlen(del) == 1);
	if (!s || !*s)
		return NULL;
	tok = *s;
	d = strstr(tok, del);
	if (d) {
		*d = '\0';
		*s = d + 1;
	} else
		*s = NULL;
	return tok;
}
#endif

static const char *
html_replace(char ch)
{
	static char buf[2];
	
	switch (ch) {
	case '<':
		return "&lt;";
	case '>':
		return "&gt;";
	case '"':
		return "&quot;";
	case '\'':
		return "&#039;";
	case '&':
		return "&amp;";
	default:
		break;
	}

	/* Echo the character back */
	buf[0] = ch;
	buf[1] = '\0';
	
	return buf;
}

/*
 * Replaces <, >, ", ' and & with &lt;, &gt;, &quot;,
 * &#039; and &amp; correspondingly.
 *
 * The returned string needs to be freed by the caller.
 */

char *
evhttp_htmlescape(const char *html)
{
	int i, new_size = 0, old_size = strlen(html);
	char *escaped_html, *p;
	
	for (i = 0; i < old_size; ++i)
		new_size += strlen(html_replace(html[i]));

	p = escaped_html = malloc(new_size + 1);
	if (escaped_html == NULL)
		event_err(1, "%s: malloc(%d)", __func__, new_size + 1);
	for (i = 0; i < old_size; ++i) {
		const char *replaced = html_replace(html[i]);
		/* this is length checked */
		strcpy(p, replaced);
		p += strlen(replaced);
	}

	*p = '\0';

	return (escaped_html);
}

const char *
evhttp_method(enum evhttp_cmd_type type)
{
	const char *method;

	switch (type) {
	case EVHTTP_REQ_GET:
		method = "GET";
		break;
	case EVHTTP_REQ_POST:
		method = "POST";
		break;
	case EVHTTP_REQ_HEAD:
		method = "HEAD";
		break;
	default:
		method = NULL;
		break;
	}

	return (method);
}

static void
evhttp_add_event(struct event *ev, int timeout, int default_timeout)
{
	if (timeout != 0) {
		struct timeval tv;
		
		evutil_timerclear(&tv);
		tv.tv_sec = timeout != -1 ? timeout : default_timeout;
		event_add(ev, &tv);
	} else {
		event_add(ev, NULL);
	}
}

void
evhttp_write_buffer(struct evhttp_connection *evcon,
    void (*cb)(struct evhttp_connection *, void *), void *arg)
{
	event_debug(("%s: preparing to write buffer\n", __func__));

	/* Set call back */
	evcon->cb = cb;
	evcon->cb_arg = arg;

	/* check if the event is already pending */
	if (event_pending(&evcon->ev, EV_WRITE|EV_TIMEOUT, NULL))
		event_del(&evcon->ev);

	event_set(&evcon->ev, evcon->fd, EV_WRITE, evhttp_write, evcon);
	EVHTTP_BASE_SET(evcon, &evcon->ev);
	evhttp_add_event(&evcon->ev, evcon->timeout, HTTP_WRITE_TIMEOUT);
}

/*
 * Create the headers need for an HTTP reply
 */
static void
evhttp_make_header_request(struct evhttp_connection *evcon,
    struct evhttp_request *req)
{
	static char line[1024];
	const char *method;
	
	evhttp_remove_header(req->output_headers, "Accept-Encoding");
	evhttp_remove_header(req->output_headers, "Proxy-Connection");

	/* Generate request line */
	method = evhttp_method(req->type);
	snprintf(line, sizeof(line), "%s %s HTTP/%d.%d\r\n",
	    method, req->uri, req->major, req->minor);
	evbuffer_add(evcon->output_buffer, line, strlen(line));

	/* Add the content length on a post request if missing */
	if (req->type == EVHTTP_REQ_POST &&
	    evhttp_find_header(req->output_headers, "Content-Length") == NULL){
		char size[12];
		snprintf(size, sizeof(size), "%ld",
			 (long)EVBUFFER_LENGTH(req->output_buffer));
		evhttp_add_header(req->output_headers, "Content-Length", size);
	}
}

static int
evhttp_is_connection_close(int flags, struct evkeyvalq* headers)
{
	if (flags & EVHTTP_PROXY_REQUEST) {
		/* proxy connection */
		const char *connection = evhttp_find_header(headers, "Proxy-Connection");
		return (connection == NULL || strcasecmp(connection, "keep-alive") != 0);
	} else {
		const char *connection = evhttp_find_header(headers, "Connection");
		return (connection != NULL && strcasecmp(connection, "close") == 0);
	}
}

static int
evhttp_is_connection_keepalive(struct evkeyvalq* headers)
{
	const char *connection = evhttp_find_header(headers, "Connection");
	return (connection != NULL 
	    && strncasecmp(connection, "keep-alive", 10) == 0);
}

/*
 * Create the headers needed for an HTTP reply
 */
static void
evhttp_make_header_response(struct evhttp_connection *evcon,
    struct evhttp_request *req)
{
	static char line[1024];
	snprintf(line, sizeof(line), "HTTP/%d.%d %d %s\r\n",
	    req->major, req->minor, req->response_code,
	    req->response_code_line);
	evbuffer_add(evcon->output_buffer, line, strlen(line));

	/* Potentially add headers for unidentified content. */
	if (EVBUFFER_LENGTH(req->output_buffer)) {
		if (evhttp_find_header(req->output_headers,
							   "Date") == NULL) {
			char date[50];
#ifndef WIN32
			struct tm cur;
#endif
			struct tm *cur_p;
			time_t t = time(NULL);
#ifdef WIN32
			cur_p = gmtime(&t);
#else
			gmtime_r(&t, &cur);
			cur_p = &cur;
#endif
			if (strftime(date, sizeof(date),
						 "%a, %d %b %Y %H:%M:%S GMT", cur_p) != 0) {
				evhttp_add_header(req->output_headers, "Date", date);
			}
		}

		if (evhttp_find_header(req->output_headers,
			"Content-Type") == NULL) {
			evhttp_add_header(req->output_headers,
			    "Content-Type", "text/html; charset=ISO-8859-1");
		}

		/* 
		 * we need to add the content length if the user did
		 * not give it, this is required for persistent
		 * connections to work.
		 */
		if (evhttp_find_header(req->output_headers,
			"Transfer-Encoding") == NULL &&
		    evhttp_find_header(req->output_headers,
			"Content-Length") == NULL) {
			static char len[12];
			snprintf(len, sizeof(len), "%ld",
			    (long)EVBUFFER_LENGTH(req->output_buffer));
			evhttp_add_header(req->output_headers,
			    "Content-Length", len);
		}
	}

	/* if the request asked for a close, we send a close, too */
	if (evhttp_is_connection_close(req->flags, req->input_headers)) {
		evhttp_remove_header(req->output_headers, "Connection");
		if (!(req->flags & EVHTTP_PROXY_REQUEST))
		    evhttp_add_header(req->output_headers, "Connection", "close");
		evhttp_remove_header(req->output_headers, "Proxy-Connection");
	}
}

void
evhttp_make_header(struct evhttp_connection *evcon, struct evhttp_request *req)
{
	static char line[1024];
	struct evkeyval *header;

	/*
	 * Depending if this is a HTTP request or response, we might need to
	 * add some new headers or remove existing headers.
	 */
	if (req->kind == EVHTTP_REQUEST) {
		evhttp_make_header_request(evcon, req);
	} else {
		evhttp_make_header_response(evcon, req);
	}

	TAILQ_FOREACH(header, req->output_headers, next) {
		snprintf(line, sizeof(line), "%s: %s\r\n",
		    header->key, header->value);
		evbuffer_add(evcon->output_buffer, line, strlen(line));
	}
	evbuffer_add(evcon->output_buffer, "\r\n", 2);

	if (EVBUFFER_LENGTH(req->output_buffer) >= 0) {
		/*
		 * For a request, we add the POST data, for a reply, this
		 * is the regular data.
		 */
		evbuffer_add_buffer(evcon->output_buffer, req->output_buffer);
	}
}

/* Separated host, port and file from URI */

int
evhttp_hostportfile(char *url, char **phost, u_short *pport, char **pfile)
{
	static char host[1024];
	static char file[1024];
	char *p, *p2;
	int len;
	u_short port;

	len = strlen(HTTP_PREFIX);
	if (strncasecmp(url, HTTP_PREFIX, len))
		return (-1);

	url += len;

	/* We might overrun */
	if (strlcpy(host, url, sizeof (host)) >= sizeof(host))
		return (-1);

	p = strchr(host, '/');
	if (p != NULL) {
		*p = '\0';
		p2 = p + 1;
	} else
		p2 = NULL;

	if (pfile != NULL) {
		/* Generate request file */
		if (p2 == NULL)
			p2 = "";
		snprintf(file, sizeof(file), "/%s", p2);
	}

	p = strchr(host, ':');
	if (p != NULL) {
		*p = '\0';
		port = atoi(p + 1);

		if (port == 0)
			return (-1);
	} else
		port = HTTP_DEFAULTPORT;

	if (phost != NULL)
		*phost = host;
	if (pport != NULL)
		*pport = port;
	if (pfile != NULL)
		*pfile = file;

	return (0);
}

static int
evhttp_connection_incoming_fail(struct evhttp_request *req,
    enum evhttp_connection_error error)
{
	switch (error) {
	case EVCON_HTTP_TIMEOUT:
	case EVCON_HTTP_EOF:
		/* 
		 * these are cases in which we probably should just
		 * close the connection and not send a reply.  this
		 * case may happen when a browser keeps a persistent
		 * connection open and we timeout on the read.
		 */
		return (-1);
	case EVCON_HTTP_INVALID_HEADER:
	default:	/* xxx: probably should just error on default */
		/* the callback looks at the uri to determine errors */
		if (req->uri) {
			free(req->uri);
			req->uri = NULL;
		}

		/* 
		 * the callback needs to send a reply, once the reply has
		 * been send, the connection should get freed.
		 */
		(*req->cb)(req, req->cb_arg);
	}
	
	return (0);
}

void
evhttp_connection_fail(struct evhttp_connection *evcon,
    enum evhttp_connection_error error)
{
	struct evhttp_request* req = TAILQ_FIRST(&evcon->requests);
	void (*cb)(struct evhttp_request *, void *);
	void *cb_arg;
	assert(req != NULL);
	
	if (evcon->flags & EVHTTP_CON_INCOMING) {
		/* 
		 * for incoming requests, there are two different
		 * failure cases.  it's either a network level error
		 * or an http layer error. for problems on the network
		 * layer like timeouts we just drop the connections.
		 * For HTTP problems, we might have to send back a
		 * reply before the connection can be freed.
		 */
		if (evhttp_connection_incoming_fail(req, error) == -1)
			evhttp_connection_free(evcon);
		return;
	}

	/* save the callback for later; the cb might free our object */
	cb = req->cb;
	cb_arg = req->cb_arg;

	TAILQ_REMOVE(&evcon->requests, req, next);
	evhttp_request_free(req);

	/* xxx: maybe we should fail all requests??? */

	/* reset the connection */
	evhttp_connection_reset(evcon);
	
	/* We are trying the next request that was queued on us */
	if (TAILQ_FIRST(&evcon->requests) != NULL)
		evhttp_connection_connect(evcon);

	/* inform the user */
	if (cb != NULL)
		(*cb)(NULL, cb_arg);
}

void
evhttp_write(int fd, short what, void *arg)
{
	struct evhttp_connection *evcon = arg;
	int n;

	if (what == EV_TIMEOUT) {
		evhttp_connection_fail(evcon, EVCON_HTTP_TIMEOUT);
		return;
	}

	n = evbuffer_write(evcon->output_buffer, fd);
	if (n == -1) {
		event_debug(("%s: evbuffer_write", __func__));
		evhttp_connection_fail(evcon, EVCON_HTTP_EOF);
		return;
	}

	if (n == 0) {
		event_debug(("%s: write nothing", __func__));
		evhttp_connection_fail(evcon, EVCON_HTTP_EOF);
		return;
	}

	if (EVBUFFER_LENGTH(evcon->output_buffer) != 0) {
		evhttp_add_event(&evcon->ev, 
		    evcon->timeout, HTTP_WRITE_TIMEOUT);
		return;
	}

	/* Activate our call back */
	if (evcon->cb != NULL)
		(*evcon->cb)(evcon, evcon->cb_arg);
}

void
evhttp_connection_done(struct evhttp_connection *evcon)
{
	struct evhttp_request *req = TAILQ_FIRST(&evcon->requests);
	int con_outgoing = evcon->flags & EVHTTP_CON_OUTGOING;
    
	/*
	 * if this is an incoming connection, we need to leave the request
	 * on the connection, so that we can reply to it.
	 */
	if (con_outgoing) {
	        int need_close;
		TAILQ_REMOVE(&evcon->requests, req, next);
		req->evcon = NULL;

		need_close = 
		    evhttp_is_connection_close(req->flags, req->input_headers) ||
		    evhttp_is_connection_close(req->flags, req->output_headers);

		/* check if we got asked to close the connection */
		if (need_close)
			evhttp_connection_reset(evcon);

		if (TAILQ_FIRST(&evcon->requests) != NULL) {
			/*
			 * We have more requests; reset the connection
			 * and deal with the next request.  xxx: no
			 * persistent connection right now
			 */
			if (evcon->state != EVCON_CONNECTED)
				evhttp_connection_connect(evcon);
			else
				evhttp_request_dispatch(evcon);
		} else if (!need_close) {
			/*
			 * The connection is going to be persistent, but we
			 * need to detect if the other side closes it.
			 */
			evhttp_connection_start_detectclose(evcon);
		}
	}

	/* notify the user of the request */
	(*req->cb)(req, req->cb_arg);

	/* if this was an outgoing request, we own and it's done. so free it */
	if (con_outgoing) {
		evhttp_request_free(req);
	}
}

/*
 * Handles reading from a chunked request.
 * return 1: all data has been read
 * return 0: more data is expected
 * return -1: data is corrupted
 */

static int
evhttp_handle_chunked_read(struct evhttp_request *req, struct evbuffer *buf)
{
	int len;

	while ((len = EVBUFFER_LENGTH(buf)) > 0) {
		if (req->ntoread < 0) {
			/* Read chunk size */
			char *p = evbuffer_readline(buf);
			char *endp;
			int error;
			if (p == NULL)
				break;
			/* the last chunk is on a new line? */
			if (strlen(p) == 0) {
				free(p);
				continue;
			}
			req->ntoread = strtol(p, &endp, 16);
			error = *p == '\0' || (*endp != '\0' && *endp != ' ');
			free(p);
			if (error) {
				/* could not get chunk size */
				return (-1);
			}
			if (req->ntoread == 0) {
				/* Last chunk */
				return (1);
			}
			continue;
		}

		/* don't have enough to complete a chunk; wait for more */
		if (len < req->ntoread)
			return (0);

		/* Completed chunk */
		evbuffer_add(req->input_buffer,
		    EVBUFFER_DATA(buf), req->ntoread);
		evbuffer_drain(buf, req->ntoread);
		req->ntoread = -1;
		if (req->chunk_cb != NULL) {
			(*req->chunk_cb)(req, req->cb_arg);
			evbuffer_drain(req->input_buffer,
			    EVBUFFER_LENGTH(req->input_buffer));
		}
	}

	return (0);
}

void
evhttp_read_body(struct evhttp_connection *evcon, struct evhttp_request *req)
{
	struct evbuffer *buf = evcon->input_buffer;
	
	if (req->chunked) {
		int res = evhttp_handle_chunked_read(req, buf);
		if (res == 1) {
			/* finished last chunk */
			evhttp_connection_done(evcon);
			return;
		} else if (res == -1) {
			/* corrupted data */
			evhttp_connection_fail(evcon,
			    EVCON_HTTP_INVALID_HEADER);
			return;
		}
	} else if (req->ntoread < 0) {
		/* Read until connection close. */
		evbuffer_add_buffer(req->input_buffer, buf);
	} else if (EVBUFFER_LENGTH(buf) >= req->ntoread) {
		/* Completed content length */
		evbuffer_add(req->input_buffer, EVBUFFER_DATA(buf),
		    req->ntoread);
		evbuffer_drain(buf, req->ntoread);
		req->ntoread = 0;
		evhttp_connection_done(evcon);
		return;
	}
	/* Read more! */
	event_set(&evcon->ev, evcon->fd, EV_READ, evhttp_read, evcon);
	EVHTTP_BASE_SET(evcon, &evcon->ev);
	evhttp_add_event(&evcon->ev, evcon->timeout, HTTP_READ_TIMEOUT);
}

/*
 * Reads data into a buffer structure until no more data
 * can be read on the file descriptor or we have read all
 * the data that we wanted to read.
 * Execute callback when done.
 */

void
evhttp_read(int fd, short what, void *arg)
{
	struct evhttp_connection *evcon = arg;
	struct evhttp_request *req = TAILQ_FIRST(&evcon->requests);
	struct evbuffer *buf = evcon->input_buffer;
	int n, len;

	if (what == EV_TIMEOUT) {
		evhttp_connection_fail(evcon, EVCON_HTTP_TIMEOUT);
		return;
	}
	n = evbuffer_read(buf, fd, -1);
	len = EVBUFFER_LENGTH(buf);
	event_debug(("%s: got %d on %d\n", __func__, n, fd));
	
	if (n == -1) {
		event_debug(("%s: evbuffer_read", __func__));
		evhttp_connection_fail(evcon, EVCON_HTTP_EOF);
		return;
	} else if (n == 0) {
		/* Connection closed */
		evhttp_connection_done(evcon);
		return;
	}
	evhttp_read_body(evcon, req);
}

void
evhttp_write_connectioncb(struct evhttp_connection *evcon, void *arg)
{
	/* This is after writing the request to the server */
	struct evhttp_request *req = TAILQ_FIRST(&evcon->requests);
	assert(req != NULL);

	/* We are done writing our header and are now expecting the response */
	req->kind = EVHTTP_RESPONSE;

	evhttp_start_read(evcon);
}

/*
 * Clean up a connection object
 */

void
evhttp_connection_free(struct evhttp_connection *evcon)
{
	struct evhttp_request *req;

	/* notify interested parties that this connection is going down */
	if (evcon->fd != -1) {
		if (evcon->state == EVCON_CONNECTED && evcon->closecb != NULL)
			(*evcon->closecb)(evcon, evcon->closecb_arg);
	}

	/* remove all requests that might be queued on this connection */
	while ((req = TAILQ_FIRST(&evcon->requests)) != NULL) {
		TAILQ_REMOVE(&evcon->requests, req, next);
		evhttp_request_free(req);
	}

	if (evcon->http_server != NULL) {
		struct evhttp *http = evcon->http_server;
		TAILQ_REMOVE(&http->connections, evcon, next);
	}

	if (event_initialized(&evcon->close_ev))
		event_del(&evcon->close_ev);

	if (event_initialized(&evcon->ev))
		event_del(&evcon->ev);
	
	if (evcon->fd != -1)
		EVUTIL_CLOSESOCKET(evcon->fd);

	if (evcon->bind_address != NULL)
		free(evcon->bind_address);

	if (evcon->address != NULL)
		free(evcon->address);

	if (evcon->input_buffer != NULL)
		evbuffer_free(evcon->input_buffer);

	if (evcon->output_buffer != NULL)
		evbuffer_free(evcon->output_buffer);

	free(evcon);
}

void
evhttp_connection_set_local_address(struct evhttp_connection *evcon,
    const char *address)
{
	assert(evcon->state == EVCON_DISCONNECTED);
	if (evcon->bind_address)
		free(evcon->bind_address);
	if ((evcon->bind_address = strdup(address)) == NULL)
		event_err(1, "%s: strdup", __func__);
}


static void
evhttp_request_dispatch(struct evhttp_connection* evcon)
{
	struct evhttp_request *req = TAILQ_FIRST(&evcon->requests);
	
	/* this should not usually happy but it's possible */
	if (req == NULL)
		return;

	/* delete possible close detection events */
	evhttp_connection_stop_detectclose(evcon);
	
	/* we assume that the connection is connected already */
	assert(evcon->state == EVCON_CONNECTED);

	/* Create the header from the store arguments */
	evhttp_make_header(evcon, req);

	evhttp_write_buffer(evcon, evhttp_write_connectioncb, NULL);
}

/* Reset our connection state */
void
evhttp_connection_reset(struct evhttp_connection *evcon)
{
	if (event_initialized(&evcon->ev))
		event_del(&evcon->ev);

	if (evcon->fd != -1) {
		/* inform interested parties about connection close */
		if (evcon->state == EVCON_CONNECTED && evcon->closecb != NULL)
			(*evcon->closecb)(evcon, evcon->closecb_arg);

		EVUTIL_CLOSESOCKET(evcon->fd);
		evcon->fd = -1;
	}
	evcon->state = EVCON_DISCONNECTED;

	/* remove unneeded flags */
	evcon->flags &= ~EVHTTP_CON_CLOSEDETECT;
}

static void
evhttp_detect_close_cb(int fd, short what, void *arg)
{
	struct evhttp_connection *evcon = arg;
	evhttp_connection_reset(evcon);
}

static void
evhttp_connection_start_detectclose(struct evhttp_connection *evcon)
{
	evcon->flags |= EVHTTP_CON_CLOSEDETECT;

	if (event_initialized(&evcon->close_ev))
		event_del(&evcon->close_ev);
	event_set(&evcon->close_ev, evcon->fd, EV_READ,
	    evhttp_detect_close_cb, evcon);
	EVHTTP_BASE_SET(evcon, &evcon->ev);
	event_add(&evcon->close_ev, NULL);
}

static void
evhttp_connection_stop_detectclose(struct evhttp_connection *evcon)
{
	evcon->flags &= ~EVHTTP_CON_CLOSEDETECT;
	event_del(&evcon->close_ev);
}

static void
evhttp_connection_retry(int fd, short what, void *arg)
{
	struct evhttp_connection *evcon = arg;

	evcon->state = EVCON_DISCONNECTED;
	evhttp_connection_connect(evcon);
}

/*
 * Call back for asynchronous connection attempt.
 */

static void
evhttp_connectioncb(int fd, short what, void *arg)
{
	struct evhttp_connection *evcon = arg;
	int error;
	socklen_t errsz = sizeof(error);
		
	if (what == EV_TIMEOUT) {
		event_debug(("%s: connection timeout for \"%s:%d\" on %d",
			__func__, evcon->address, evcon->port, evcon->fd));
		goto cleanup;
	}

	/* Check if the connection completed */
	if (getsockopt(evcon->fd, SOL_SOCKET, SO_ERROR, (void*)&error,
		       &errsz) == -1) {
		event_debug(("%s: getsockopt for \"%s:%d\" on %d",
			__func__, evcon->address, evcon->port, evcon->fd));
		goto cleanup;
	}

	if (error) {
		event_debug(("%s: connect failed for \"%s:%d\" on %d: %s",
		    __func__, evcon->address, evcon->port, evcon->fd,
			strerror(error)));
		goto cleanup;
	}

	/* We are connected to the server now */
	event_debug(("%s: connected to \"%s:%d\" on %d\n",
			__func__, evcon->address, evcon->port, evcon->fd));

	/* Reset the retry count as we were successful in connecting */
	evcon->retry_cnt = 0;
	evcon->state = EVCON_CONNECTED;

	/* try to start requests that have queued up on this connection */
	evhttp_request_dispatch(evcon);
	return;

 cleanup:
	if (evcon->retry_max < 0 || evcon->retry_cnt < evcon->retry_max) {
		evtimer_set(&evcon->ev, evhttp_connection_retry, evcon);
		EVHTTP_BASE_SET(evcon, &evcon->ev);
		evhttp_add_event(&evcon->ev, MIN(3600, 2 << evcon->retry_cnt),
		    HTTP_CONNECT_TIMEOUT);
		evcon->retry_cnt++;
		return;
	}
	evhttp_connection_reset(evcon);

	/* for now, we just signal all requests by executing their callbacks */
	while (TAILQ_FIRST(&evcon->requests) != NULL) {
		struct evhttp_request *request = TAILQ_FIRST(&evcon->requests);
		TAILQ_REMOVE(&evcon->requests, request, next);
		request->evcon = NULL;

		/* we might want to set an error here */
		request->cb(request, request->cb_arg);
		evhttp_request_free(request);
	}
}

/*
 * Check if we got a valid response code.
 */

int
evhttp_valid_response_code(int code)
{
	if (code == 0)
		return (0);

	return (1);
}

/* Parses the status line of a web server */

int
evhttp_parse_response_line(struct evhttp_request *req, char *line)
{
	char *protocol;
	char *number;
	char *readable;

	protocol = strsep(&line, " ");
	if (line == NULL)
		return (-1);
	number = strsep(&line, " ");
	if (line == NULL)
		return (-1);
	readable = line;

	if (strcmp(protocol, "HTTP/1.0") == 0) {
		req->major = 1;
		req->minor = 0;
	} else if (strcmp(protocol, "HTTP/1.1") == 0) {
		req->major = 1;
		req->minor = 1;
	} else {
		event_debug(("%s: bad protocol \"%s\"",
			__func__, protocol));
		return (-1);
	}

	req->response_code = atoi(number);
	if (!evhttp_valid_response_code(req->response_code)) {
		event_debug(("%s: bad response code \"%s\"",
			__func__, number));
		return (-1);
	}

	if ((req->response_code_line = strdup(readable)) == NULL)
		event_err(1, "%s: strdup", __func__);

	return (0);
}

/* Parse the first line of a HTTP request */

int
evhttp_parse_request_line(struct evhttp_request *req, char *line)
{
	char *method;
	char *uri;
	char *version;

	/* Parse the request line */
	method = strsep(&line, " ");
	if (line == NULL)
		return (-1);
	uri = strsep(&line, " ");
	if (line == NULL)
		return (-1);
	version = strsep(&line, " ");
	if (line != NULL)
		return (-1);

	/* First line */
	if (strcmp(method, "GET") == 0) {
		req->type = EVHTTP_REQ_GET;
	} else if (strcmp(method, "POST") == 0) {
		req->type = EVHTTP_REQ_POST;
	} else if (strcmp(method, "HEAD") == 0) {
		req->type = EVHTTP_REQ_HEAD;
	} else {
		event_debug(("%s: bad method %s on request %p from %s",
			__func__, method, req, req->remote_host));
		return (-1);
	}

	if (strcmp(version, "HTTP/1.0") == 0) {
		req->major = 1;
		req->minor = 0;
	} else if (strcmp(version, "HTTP/1.1") == 0) {
		req->major = 1;
		req->minor = 1;
	} else {
		event_debug(("%s: bad version %s on request %p from %s",
			__func__, version, req, req->remote_host));
		return (-1);
	}

	if ((req->uri = strdup(uri)) == NULL) {
		event_debug(("%s: evhttp_decode_uri", __func__));
		return (-1);
	}

	/* determine if it's a proxy request */
	if (strlen(req->uri) > 0 && req->uri[0] != '/')
		req->flags |= EVHTTP_PROXY_REQUEST;

	return (0);
}

const char *
evhttp_find_header(const struct evkeyvalq *headers, const char *key)
{
	struct evkeyval *header;

	TAILQ_FOREACH(header, headers, next) {
		if (strcasecmp(header->key, key) == 0)
			return (header->value);
	}

	return (NULL);
}

void
evhttp_clear_headers(struct evkeyvalq *headers)
{
	struct evkeyval *header;

	for (header = TAILQ_FIRST(headers);
	    header != NULL;
	    header = TAILQ_FIRST(headers)) {
		TAILQ_REMOVE(headers, header, next);
		free(header->key);
		free(header->value);
		free(header);
	}
}

/*
 * Returns 0,  if the header was successfully removed.
 * Returns -1, if the header could not be found.
 */

int
evhttp_remove_header(struct evkeyvalq *headers, const char *key)
{
	struct evkeyval *header;

	TAILQ_FOREACH(header, headers, next) {
		if (strcasecmp(header->key, key) == 0)
			break;
	}

	if (header == NULL)
		return (-1);

	/* Free and remove the header that we found */
	TAILQ_REMOVE(headers, header, next);
	free(header->key);
	free(header->value);
	free(header);

	return (0);
}

int
evhttp_add_header(struct evkeyvalq *headers,
    const char *key, const char *value)
{
	struct evkeyval *header = NULL;

	event_debug(("%s: key: %s val: %s\n", __func__, key, value));

	if (strchr(value, '\r') != NULL || strchr(value, '\n') != NULL ||
	    strchr(key, '\r') != NULL || strchr(key, '\n') != NULL) {
		/* drop illegal headers */
		event_debug(("%s: dropping illegal header\n", __func__));
		return (-1);
	}

	header = calloc(1, sizeof(struct evkeyval));
	if (header == NULL) {
		event_warn("%s: calloc", __func__);
		return (-1);
	}
	if ((header->key = strdup(key)) == NULL) {
		free(header);
		event_warn("%s: strdup", __func__);
		return (-1);
	}
	if ((header->value = strdup(value)) == NULL) {
		free(header->key);
		free(header);
		event_warn("%s: strdup", __func__);
		return (-1);
	}

	TAILQ_INSERT_TAIL(headers, header, next);

	return (0);
}

/*
 * Parses header lines from a request or a response into the specified
 * request object given an event buffer.
 *
 * Returns
 *   -1  on error
 *    0  when we need to read more headers
 *    1  when all headers have been read.
 */

int
evhttp_parse_lines(struct evhttp_request *req, struct evbuffer* buffer)
{
	char *line;
	int done = 0;

	struct evkeyvalq* headers = req->input_headers;
	while ((line = evbuffer_readline(buffer)) != NULL) {
		char *skey, *svalue;

		if (*line == '\0') { /* Last header - Done */
			done = 1;
			free (line);
			break;
		}

		/* Processing of header lines */
		if (req->got_firstline == 0) {
			switch (req->kind) {
			case EVHTTP_REQUEST:
				if (evhttp_parse_request_line(req, line) == -1)
					goto error;
				break;
			case EVHTTP_RESPONSE:
				if (evhttp_parse_response_line(req, line) == -1)
					goto error;
				break;
			default:
				goto error;
			}
			req->got_firstline = 1;
		} else {
			/* Regular header */
			svalue = line;
			skey = strsep(&svalue, ":");
			if (svalue == NULL)
				goto error;

			svalue += strspn(svalue, " ");

			if (evhttp_add_header(headers, skey, svalue) == -1)
				goto error;
		}

		free (line);
	}

	return (done);

 error:
	free (line);
	return (-1);
}

static int
evhttp_get_body_length(struct evhttp_request *req)
{
	struct evkeyvalq *headers = req->input_headers;
	const char *content_length;
	const char *connection;

	content_length = evhttp_find_header(headers, "Content-Length");
	connection = evhttp_find_header(headers, "Connection");
		
	if (content_length == NULL && connection == NULL)
		req->ntoread = -1;
	else if (content_length == NULL &&
	    strcasecmp(connection, "Close") != 0) {
		/* Bad combination, we don't know when it will end */
		event_warnx("%s: we got no content length, but the "
		    "server wants to keep the connection open: %s.",
		    __func__, connection);
		return (-1);
	} else if (content_length == NULL) {
		req->ntoread = -1;
	} else {
		char *endp;
		req->ntoread = strtol(content_length, &endp, 10);
		if (*content_length == '\0' || *endp != '\0') {
			event_warnx("%s: illegal content length: %s",
			    __func__, content_length);
			return (-1);
		}
	}
		
	event_debug(("%s: bytes to read: %d (in buffer %d)\n",
		__func__, req->ntoread,
		EVBUFFER_LENGTH(req->evcon->input_buffer)));

	return (0);
}

static void
evhttp_get_body(struct evhttp_connection *evcon, struct evhttp_request *req)
{
	const char *xfer_enc;
	
	/* If this is a request without a body, then we are done */
	if (req->kind == EVHTTP_REQUEST && req->type != EVHTTP_REQ_POST) {
		evhttp_connection_done(evcon);
		return;
	}
	xfer_enc = evhttp_find_header(req->input_headers, "Transfer-Encoding");
	if (xfer_enc != NULL && strcasecmp(xfer_enc, "chunked") == 0) {
		req->chunked = 1;
		req->ntoread = -1;
	} else {
		if (evhttp_get_body_length(req) == -1) {
			evhttp_connection_fail(evcon,
			    EVCON_HTTP_INVALID_HEADER);
			return;
		}
	}
	evhttp_read_body(evcon, req);
}

void
evhttp_read_header(int fd, short what, void *arg)
{
	struct evhttp_connection *evcon = arg;
	struct evhttp_request *req = TAILQ_FIRST(&evcon->requests);
	int n, res;

	if (what == EV_TIMEOUT) {
		event_debug(("%s: timeout on %d\n", __func__, fd));
		evhttp_connection_fail(evcon, EVCON_HTTP_TIMEOUT);
		return;
	}

	n = evbuffer_read(evcon->input_buffer, fd, -1);
	if (n == 0) {
		event_debug(("%s: no more data on %d", __func__, fd));
		evhttp_connection_fail(evcon, EVCON_HTTP_EOF);
		return;
	}
	if (n == -1) {
		event_debug(("%s: bad read on %d", __func__, fd));
		evhttp_connection_fail(evcon, EVCON_HTTP_EOF);
		return;
	}

	res = evhttp_parse_lines(req, evcon->input_buffer);
	if (res == -1) {
		/* Error while reading, terminate */
		event_debug(("%s: bad header lines on %d\n", __func__, fd));
		evhttp_connection_fail(evcon, EVCON_HTTP_INVALID_HEADER);
		return;
	} else if (res == 0) {
		/* Need more header lines */
		evhttp_add_event(&evcon->ev, 
		    evcon->timeout, HTTP_READ_TIMEOUT);
		return;
	}

	/* Done reading headers, do the real work */
	switch (req->kind) {
	case EVHTTP_REQUEST:
		event_debug(("%s: checking for post data on %d\n",
				__func__, fd));
		evhttp_get_body(evcon, req);
		break;

	case EVHTTP_RESPONSE:
		if (req->response_code == HTTP_NOCONTENT ||
		    req->response_code == HTTP_NOTMODIFIED ||
		    (req->response_code >= 100 && req->response_code < 200)) {
			event_debug(("%s: skipping body for code %d\n",
					__func__, req->response_code));
			evhttp_connection_done(evcon);
		} else {
			event_debug(("%s: start of read body for %s on %d\n",
				__func__, req->remote_host, fd));
			evhttp_get_body(evcon, req);
		}
		break;

	default:
		event_warnx("%s: bad header on %d", __func__, fd);
		evhttp_connection_fail(evcon, EVCON_HTTP_INVALID_HEADER);
		break;
	}
}

/*
 * Creates a TCP connection to the specified port and executes a callback
 * when finished.  Failure or sucess is indicate by the passed connection
 * object.
 *
 * Although this interface accepts a hostname, it is intended to take
 * only numeric hostnames so that non-blocking DNS resolution can
 * happen elsewhere.
 */

struct evhttp_connection *
evhttp_connection_new(const char *address, unsigned short port)
{
	struct evhttp_connection *evcon = NULL;
	
	event_debug(("Attempting connection to %s:%d\n", address, port));

	if ((evcon = calloc(1, sizeof(struct evhttp_connection))) == NULL) {
		event_warn("%s: calloc failed", __func__);
		goto error;
	}

	evcon->fd = -1;
	evcon->port = port;

	evcon->timeout = -1;
	evcon->retry_cnt = evcon->retry_max = 0;

	if ((evcon->address = strdup(address)) == NULL) {
		event_warn("%s: strdup failed", __func__);
		goto error;
	}

	if ((evcon->input_buffer = evbuffer_new()) == NULL) {
		event_warn("%s: evbuffer_new failed", __func__);
		goto error;
	}

	if ((evcon->output_buffer = evbuffer_new()) == NULL) {
		event_warn("%s: evbuffer_new failed", __func__);
		goto error;
	}
	
	evcon->state = EVCON_DISCONNECTED;
	TAILQ_INIT(&evcon->requests);

	return (evcon);
	
 error:
	if (evcon != NULL)
		evhttp_connection_free(evcon);
	return (NULL);
}

void evhttp_connection_set_base(struct evhttp_connection *evcon,
    struct event_base *base)
{
	assert(evcon->base == NULL);
	assert(evcon->state == EVCON_DISCONNECTED);
	evcon->base = base;
}

void
evhttp_connection_set_timeout(struct evhttp_connection *evcon,
    int timeout_in_secs)
{
	evcon->timeout = timeout_in_secs;
}

void
evhttp_connection_set_retries(struct evhttp_connection *evcon,
    int retry_max)
{
	evcon->retry_max = retry_max;
}

void
evhttp_connection_set_closecb(struct evhttp_connection *evcon,
    void (*cb)(struct evhttp_connection *, void *), void *cbarg)
{
	evcon->closecb = cb;
	evcon->closecb_arg = cbarg;
}

void
evhttp_connection_get_peer(struct evhttp_connection *evcon,
    char **address, u_short *port)
{
	*address = evcon->address;
	*port = evcon->port;
}

int
evhttp_connection_connect(struct evhttp_connection *evcon)
{
	if (evcon->state == EVCON_CONNECTING)
		return (0);
	
	evhttp_connection_reset(evcon);

	assert(!(evcon->flags & EVHTTP_CON_INCOMING));
	evcon->flags |= EVHTTP_CON_OUTGOING;
	
	evcon->fd = bind_socket(evcon->bind_address, 0);
	if (evcon->fd == -1) {
		event_debug(("%s: failed to bind to \"%s\"",
			__func__, evcon->bind_address));
		return (-1);
	}

	if (socket_connect(evcon->fd, evcon->address, evcon->port) == -1) {
		EVUTIL_CLOSESOCKET(evcon->fd); evcon->fd = -1;
		return (-1);
	}

	/* Set up a callback for successful connection setup */
	event_set(&evcon->ev, evcon->fd, EV_WRITE, evhttp_connectioncb, evcon);
	EVHTTP_BASE_SET(evcon, &evcon->ev);
	evhttp_add_event(&evcon->ev, evcon->timeout, HTTP_CONNECT_TIMEOUT);

	evcon->state = EVCON_CONNECTING;
	
	return (0);
}

/*
 * Starts an HTTP request on the provided evhttp_connection object.
 * If the connection object is not connected to the web server already,
 * this will start the connection.
 */

int
evhttp_make_request(struct evhttp_connection *evcon,
    struct evhttp_request *req,
    enum evhttp_cmd_type type, const char *uri)
{
	/* We are making a request */
	req->kind = EVHTTP_REQUEST;
	req->type = type;
	if (req->uri != NULL)
		free(req->uri);
	if ((req->uri = strdup(uri)) == NULL)
		event_err(1, "%s: strdup", __func__);

	/* Set the protocol version if it is not supplied */
	if (!req->major && !req->minor) {
		req->major = 1;
		req->minor = 1;
	}
	
	assert(req->evcon == NULL);
	req->evcon = evcon;
	assert(!(req->flags & EVHTTP_REQ_OWN_CONNECTION));
	
	TAILQ_INSERT_TAIL(&evcon->requests, req, next);

	/* If the connection object is not connected; make it so */
	if (evcon->state != EVCON_CONNECTED)
		return (evhttp_connection_connect(evcon));

	/*
	 * If it's connected already and we are the first in the queue,
	 * then we can dispatch this request immediately.  Otherwise, it
	 * will be dispatched once the pending requests are completed.
	 */
	if (TAILQ_FIRST(&evcon->requests) == req)
		evhttp_request_dispatch(evcon);

	return (0);
}

/*
 * Reads data from file descriptor into request structure
 * Request structure needs to be set up correctly.
 */

void
evhttp_start_read(struct evhttp_connection *evcon)
{
	/* Set up an event to read the headers */
	if (event_initialized(&evcon->ev))
		event_del(&evcon->ev);
	event_set(&evcon->ev, evcon->fd, EV_READ, evhttp_read_header, evcon);
	EVHTTP_BASE_SET(evcon, &evcon->ev);
	
	evhttp_add_event(&evcon->ev, evcon->timeout, HTTP_READ_TIMEOUT);
}

void
evhttp_send_done(struct evhttp_connection *evcon, void *arg)
{
	int need_close;
	struct evhttp_request *req = TAILQ_FIRST(&evcon->requests);
	TAILQ_REMOVE(&evcon->requests, req, next);

	/* delete possible close detection events */
	evhttp_connection_stop_detectclose(evcon);
	
	need_close =
	    (req->minor == 0 &&
		!evhttp_is_connection_keepalive(req->input_headers))||
	    evhttp_is_connection_close(req->flags, req->input_headers) ||
	    evhttp_is_connection_close(req->flags, req->output_headers);

	assert(req->flags & EVHTTP_REQ_OWN_CONNECTION);
	evhttp_request_free(req);

	if (need_close) {
		evhttp_connection_free(evcon);
		return;
	} 

	/* we have a persistent connection; try to accept another request. */
	if (evhttp_associate_new_request_with_connection(evcon) == -1)
		evhttp_connection_free(evcon);
}

/*
 * Returns an error page.
 */

void
evhttp_send_error(struct evhttp_request *req, int error, const char *reason)
{
	char *fmt = "<HTML><HEAD>\n"
	    "<TITLE>%d %s</TITLE>\n"
	    "</HEAD><BODY>\n"
	    "<H1>Method Not Implemented</H1>\n"
	    "Invalid method in request<P>\n"
	    "</BODY></HTML>\n";

	struct evbuffer *buf = evbuffer_new();

	/* close the connection on error */
	evhttp_add_header(req->output_headers, "Connection", "close");

	evhttp_response_code(req, error, reason);

	evbuffer_add_printf(buf, fmt, error, reason);

	evhttp_send_page(req, buf);

	evbuffer_free(buf);
}

/* Requires that headers and response code are already set up */

static inline void
evhttp_send(struct evhttp_request *req, struct evbuffer *databuf)
{
	struct evhttp_connection *evcon = req->evcon;

	assert(TAILQ_FIRST(&evcon->requests) == req);

	/* xxx: not sure if we really should expose the data buffer this way */
	if (databuf != NULL)
		evbuffer_add_buffer(req->output_buffer, databuf);
	
	/* Adds headers to the response */
	evhttp_make_header(evcon, req);

	evhttp_write_buffer(evcon, evhttp_send_done, NULL);
}

void
evhttp_send_reply(struct evhttp_request *req, int code, const char *reason,
    struct evbuffer *databuf)
{
	/* set up to watch for client close */
	evhttp_connection_start_detectclose(req->evcon);
	evhttp_response_code(req, code, reason);
	
	evhttp_send(req, databuf);
}

void
evhttp_send_reply_start(struct evhttp_request *req, int code,
    const char *reason)
{
	/* set up to watch for client close */
	evhttp_connection_start_detectclose(req->evcon);
	evhttp_response_code(req, code, reason);
	if (req->major == 1 && req->minor == 1) {
		/* use chunked encoding for HTTP/1.1 */
		evhttp_add_header(req->output_headers, "Transfer-Encoding",
		    "chunked");
		req->chunked = 1;
	}
	evhttp_make_header(req->evcon, req);
	evhttp_write_buffer(req->evcon, NULL, NULL);
}

void
evhttp_send_reply_chunk(struct evhttp_request *req, struct evbuffer *databuf)
{
	if (req->chunked) {
		evbuffer_add_printf(req->evcon->output_buffer, "%x\r\n",
		    EVBUFFER_LENGTH(databuf));
	}
	evbuffer_add_buffer(req->evcon->output_buffer, databuf);
	evhttp_write_buffer(req->evcon, NULL, NULL);
}

void
evhttp_send_reply_end(struct evhttp_request *req)
{
	struct evhttp_connection *evcon = req->evcon;

	if (req->chunked) {
		evbuffer_add(req->evcon->output_buffer, "0\r\n\r\n", 5);
		evhttp_write_buffer(req->evcon, evhttp_send_done, NULL);
		req->chunked = 0;
	} else if (!event_pending(&evcon->ev, EV_WRITE|EV_TIMEOUT, NULL)) {
		/* let the connection know that we are done with the request */
		evhttp_send_done(evcon, NULL);
	} else {
		/* make the callback execute after all data has been written */
		evcon->cb = evhttp_send_done;
		evcon->cb_arg = NULL;
	}
}

void
evhttp_response_code(struct evhttp_request *req, int code, const char *reason)
{
	req->kind = EVHTTP_RESPONSE;
	req->response_code = code;
	if (req->response_code_line != NULL)
		free(req->response_code_line);
	req->response_code_line = strdup(reason);
}

void
evhttp_send_page(struct evhttp_request *req, struct evbuffer *databuf)
{
	if (!req->major || !req->minor) {
		req->major = 1;
		req->minor = 1;
	}
	
	if (req->kind != EVHTTP_RESPONSE)
		evhttp_response_code(req, 200, "OK");

	evhttp_clear_headers(req->output_headers);
	evhttp_add_header(req->output_headers, "Content-Type", "text/html");
	evhttp_add_header(req->output_headers, "Connection", "close");

	evhttp_send(req, databuf);
}

static const char uri_chars[256] = {
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 1, 0, 0, 1, 0, 0, 1,   1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 1, 0, 0,
	/* 64 */
	1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 0, 0, 1,
	0, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 1, 1, 1, 1, 1,
	1, 1, 1, 1, 1, 1, 1, 1,   1, 1, 1, 0, 0, 0, 1, 0,
	/* 128 */
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	/* 192 */
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
	0, 0, 0, 0, 0, 0, 0, 0,   0, 0, 0, 0, 0, 0, 0, 0,
};

/*
 * Helper functions to encode/decode a URI.
 * The returned string must be freed by the caller.
 */
char *
evhttp_encode_uri(const char *uri)
{
	struct evbuffer *buf = evbuffer_new();
	char *p;

	for (p = (char *)uri; *p != '\0'; p++) {
		if (uri_chars[(u_char)(*p)]) {
			evbuffer_add(buf, p, 1);
		} else {
			evbuffer_add_printf(buf, "%%%02X", (u_char)(*p));
		}
	}
	evbuffer_add(buf, "", 1);
	p = strdup((char *)EVBUFFER_DATA(buf));
	evbuffer_free(buf);
	
	return (p);
}

char *
evhttp_decode_uri(const char *uri)
{
	char c, *ret;
	int i, j, in_query = 0;
	
	ret = malloc(strlen(uri) + 1);
	if (ret == NULL)
		event_err(1, "%s: malloc(%d)", __func__, strlen(uri) + 1);

	for (i = j = 0; uri[i] != '\0'; i++) {
		c = uri[i];
		if (c == '?') {
			in_query = 1;
		} else if (c == '+' && in_query) {
			c = ' ';
		} else if (c == '%' && isxdigit((unsigned char)uri[i+1]) &&
		    isxdigit((unsigned char)uri[i+2])) {
			char tmp[] = { uri[i+1], uri[i+2], '\0' };
			c = (char)strtol(tmp, NULL, 16);
			i += 2;
		}
		ret[j++] = c;
	}
	ret[j] = '\0';
	
	return (ret);
}

/* 
 * Helper function to parse out arguments in a query.
 * The arguments are separated by key and value.
 * URI should already be decoded.
 */

void
evhttp_parse_query(const char *uri, struct evkeyvalq *headers)
{
	char *line;
	char *argument;
	char *p;

	TAILQ_INIT(headers);

	/* No arguments - we are done */
	if (strchr(uri, '?') == NULL)
		return;

	if ((line = strdup(uri)) == NULL)
		event_err(1, "%s: strdup", __func__);


	argument = line;

	/* We already know that there has to be a ? */
	strsep(&argument, "?");

	p = argument;
	while (p != NULL && *p != '\0') {
		char *key, *value;
		argument = strsep(&p, "&");

		value = argument;
		key = strsep(&value, "=");
		if (value == NULL)
			goto error;

		value = evhttp_decode_uri(value);
		event_debug(("Query Param: %s -> %s\n", key, value));
		evhttp_add_header(headers, key, value);
		free(value);
	}

 error:
	free(line);
}

static struct evhttp_cb *
evhttp_dispatch_callback(struct httpcbq *callbacks, struct evhttp_request *req)
{
	struct evhttp_cb *cb;
	size_t offset = 0;

	/* Test for different URLs */
	char *p = strchr(req->uri, '?');
	if (p != NULL)
		offset = (size_t)(p - req->uri);

	TAILQ_FOREACH(cb, callbacks, next) {
		int res = 0;
		if (p == NULL) {
			res = strcmp(cb->what, req->uri) == 0;
		} else {
			res = ((strncmp(cb->what, req->uri, offset) == 0) &&
					(cb->what[offset] == '\0'));
		}

		if (res)
			return (cb);
	}

	return (NULL);
}

void
evhttp_handle_request(struct evhttp_request *req, void *arg)
{
	struct evhttp *http = arg;
	struct evhttp_cb *cb = NULL;

	if (req->uri == NULL) {
		evhttp_send_error(req, HTTP_BADREQUEST, "Bad Request");
		return;
	}

	if ((cb = evhttp_dispatch_callback(&http->callbacks, req)) != NULL) {
		(*cb->cb)(req, cb->cbarg);
		return;
	}

	/* Generic call back */
	if (http->gencb) {
		(*http->gencb)(req, http->gencbarg);
		return;
	} else {
		/* We need to send a 404 here */
		char *fmt = "<html><head>"
		    "<title>404 Not Found</title>"
		    "</head><body>"
		    "<h1>Not Found</h1>"
		    "<p>The requested URL %s was not found on this server.</p>"
		    "</body></html>\n";

		char *escaped_html = evhttp_htmlescape(req->uri);
		struct evbuffer *buf = evbuffer_new();

		evhttp_response_code(req, HTTP_NOTFOUND, "Not Found");

		evbuffer_add_printf(buf, fmt, escaped_html);

		free(escaped_html);
		
		evhttp_send_page(req, buf);

		evbuffer_free(buf);
	}
}

static void
accept_socket(int fd, short what, void *arg)
{
	struct evhttp *http = arg;
	struct sockaddr_storage ss;
	socklen_t addrlen = sizeof(ss);
	int nfd;

	if ((nfd = accept(fd, (struct sockaddr *)&ss, &addrlen)) == -1) {
		event_warn("%s: bad accept", __func__);
		return;
	}
	if (evutil_make_socket_nonblocking(nfd) < 0)
		return;

	evhttp_get_request(http, nfd, (struct sockaddr *)&ss, addrlen);
}

int
evhttp_bind_socket(struct evhttp *http, const char *address, u_short port)
{
	struct event *ev = &http->bind_ev;
	int fd;

	if ((fd = bind_socket(address, port)) == -1)
		return (-1);

	if (listen(fd, 10) == -1) {
		event_warn("%s: listen", __func__);
		EVUTIL_CLOSESOCKET(fd);
		return (-1);
	}

	/* Schedule the socket for accepting */
	event_set(ev, fd, EV_READ | EV_PERSIST, accept_socket, http);
	EVHTTP_BASE_SET(http, ev);
	event_add(ev, NULL);

	event_debug(("Bound to port %d - Awaiting connections ... ", port));

	return (0);
}

static struct evhttp*
evhttp_new_object()
{
	struct evhttp *http = NULL;

	if ((http = calloc(1, sizeof(struct evhttp))) == NULL) {
		event_warn("%s: calloc", __func__);
		return (NULL);
	}

	http->timeout = -1;

	TAILQ_INIT(&http->callbacks);
	TAILQ_INIT(&http->connections);

	return (http);
}

struct evhttp *
evhttp_new(struct event_base *base)
{
	struct evhttp *http = evhttp_new_object();

	http->base = base;

	return (http);
}

/*
 * Start a web server on the specified address and port.
 */

struct evhttp *
evhttp_start(const char *address, u_short port)
{
	struct evhttp *http = evhttp_new_object();

	if (evhttp_bind_socket(http, address, port) == -1) {
		free(http);
		return (NULL);
	}

	return (http);
}

void
evhttp_free(struct evhttp* http)
{
	struct evhttp_cb *http_cb;
	struct evhttp_connection *evcon;
	int fd = http->bind_ev.ev_fd;

	/* Remove the accepting part */
	event_del(&http->bind_ev);
	EVUTIL_CLOSESOCKET(fd);

	while ((evcon = TAILQ_FIRST(&http->connections)) != NULL) {
		/* evhttp_connection_free removes the connection */
		evhttp_connection_free(evcon);
	}

	while ((http_cb = TAILQ_FIRST(&http->callbacks)) != NULL) {
		TAILQ_REMOVE(&http->callbacks, http_cb, next);
		free(http_cb->what);
		free(http_cb);
	}
	
	free(http);
}

void
evhttp_set_timeout(struct evhttp* http, int timeout_in_secs)
{
	http->timeout = timeout_in_secs;
}

void
evhttp_set_cb(struct evhttp *http, const char *uri,
    void (*cb)(struct evhttp_request *, void *), void *cbarg)
{
	struct evhttp_cb *http_cb;

	if ((http_cb = calloc(1, sizeof(struct evhttp_cb))) == NULL)
		event_err(1, "%s: calloc", __func__);

	http_cb->what = strdup(uri);
	http_cb->cb = cb;
	http_cb->cbarg = cbarg;

	TAILQ_INSERT_TAIL(&http->callbacks, http_cb, next);
}

int
evhttp_del_cb(struct evhttp *http, const char *uri)
{
	struct evhttp_cb *http_cb;

	TAILQ_FOREACH(http_cb, &http->callbacks, next) {
		if (strcmp(http_cb->what, uri) == 0)
			break;
	}
	if (http_cb == NULL)
		return (-1);

	TAILQ_REMOVE(&http->callbacks, http_cb, next);
	free(http_cb->what);
	free(http_cb);

	return (0);
}

void
evhttp_set_gencb(struct evhttp *http,
    void (*cb)(struct evhttp_request *, void *), void *cbarg)
{
	http->gencb = cb;
	http->gencbarg = cbarg;
}

/*
 * Request related functions
 */

struct evhttp_request *
evhttp_request_new(void (*cb)(struct evhttp_request *, void *), void *arg)
{
	struct evhttp_request *req = NULL;

	/* Allocate request structure */
	if ((req = calloc(1, sizeof(struct evhttp_request))) == NULL) {
		event_warn("%s: calloc", __func__);
		goto error;
	}

	req->kind = EVHTTP_RESPONSE;
	req->input_headers = calloc(1, sizeof(struct evkeyvalq));
	if (req->input_headers == NULL) {
		event_warn("%s: calloc", __func__);
		goto error;
	}
	TAILQ_INIT(req->input_headers);

	req->output_headers = calloc(1, sizeof(struct evkeyvalq));
	if (req->output_headers == NULL) {
		event_warn("%s: calloc", __func__);
		goto error;
	}
	TAILQ_INIT(req->output_headers);

	if ((req->input_buffer = evbuffer_new()) == NULL) {
		event_warn("%s: evbuffer_new", __func__);
		goto error;
	}

	if ((req->output_buffer = evbuffer_new()) == NULL) {
		event_warn("%s: evbuffer_new", __func__);
		goto error;
	}

	req->cb = cb;
	req->cb_arg = arg;

	return (req);

 error:
	if (req != NULL)
		evhttp_request_free(req);
	return (NULL);
}

void
evhttp_request_free(struct evhttp_request *req)
{
	if (req->remote_host != NULL)
		free(req->remote_host);
	if (req->uri != NULL)
		free(req->uri);
	if (req->response_code_line != NULL)
		free(req->response_code_line);

	evhttp_clear_headers(req->input_headers);
	free(req->input_headers);

	evhttp_clear_headers(req->output_headers);
	free(req->output_headers);

	if (req->input_buffer != NULL)
		evbuffer_free(req->input_buffer);

	if (req->output_buffer != NULL)
		evbuffer_free(req->output_buffer);

	free(req);
}

void
evhttp_request_set_chunked_cb(struct evhttp_request *req,
    void (*cb)(struct evhttp_request *, void *))
{
	req->chunk_cb = cb;
}

/*
 * Allows for inspection of the request URI
 */

const char *
evhttp_request_uri(struct evhttp_request *req) {
	if (req->uri == NULL)
		event_debug(("%s: request %p has no uri\n", req));
	return (req->uri);
}

/*
 * Takes a file descriptor to read a request from.
 * The callback is executed once the whole request has been read.
 */

static struct evhttp_connection*
evhttp_get_request_connection(
	struct evhttp* http,
	int fd, struct sockaddr *sa, socklen_t salen)
{
	struct evhttp_connection *evcon;
	char *hostname, *portname;

	name_from_addr(sa, salen, &hostname, &portname);
	event_debug(("%s: new request from %s:%s on %d\n",
			__func__, hostname, portname, fd));

	/* we need a connection object to put the http request on */
	if ((evcon = evhttp_connection_new(hostname, atoi(portname))) == NULL)
		return (NULL);

	/* associate the base if we have one*/
	evhttp_connection_set_base(evcon, http->base);

	evcon->flags |= EVHTTP_CON_INCOMING;
	evcon->state = EVCON_CONNECTED;
	
	evcon->fd = fd;

	return (evcon);
}

static int
evhttp_associate_new_request_with_connection(struct evhttp_connection *evcon)
{
	struct evhttp *http = evcon->http_server;
	struct evhttp_request *req;
	if ((req = evhttp_request_new(evhttp_handle_request, http)) == NULL)
		return (-1);

	req->evcon = evcon;	/* the request ends up owning the connection */
	req->flags |= EVHTTP_REQ_OWN_CONNECTION;
	
	TAILQ_INSERT_TAIL(&evcon->requests, req, next);
	
	req->kind = EVHTTP_REQUEST;
	
	if ((req->remote_host = strdup(evcon->address)) == NULL)
		event_err(1, "%s: strdup", __func__);
	req->remote_port = evcon->port;

	evhttp_start_read(evcon);
	
	return (0);
}

void
evhttp_get_request(struct evhttp *http, int fd,
    struct sockaddr *sa, socklen_t salen)
{
	struct evhttp_connection *evcon;

	evcon = evhttp_get_request_connection(http, fd, sa, salen);
	if (evcon == NULL)
		return;

	/* the timeout can be used by the server to close idle connections */
	if (http->timeout != -1)
		evhttp_connection_set_timeout(evcon, http->timeout);

	/* 
	 * if we want to accept more than one request on a connection,
	 * we need to know which http server it belongs to.
	 */
	evcon->http_server = http;
	TAILQ_INSERT_TAIL(&http->connections, evcon, next);
	
	if (evhttp_associate_new_request_with_connection(evcon) == -1)
		evhttp_connection_free(evcon);
}


/*
 * Network helper functions that we do not want to export to the rest of
 * the world.
 */
#if 0 /* Unused */
static struct addrinfo *
addr_from_name(char *address)
{
#ifdef HAVE_GETADDRINFO
        struct addrinfo ai, *aitop;
        int ai_result;

        memset(&ai, 0, sizeof(ai));
        ai.ai_family = AF_INET;
        ai.ai_socktype = SOCK_RAW;
        ai.ai_flags = 0;
        if ((ai_result = getaddrinfo(address, NULL, &ai, &aitop)) != 0) {
                if ( ai_result == EAI_SYSTEM )
                        event_warn("getaddrinfo");
                else
                        event_warnx("getaddrinfo: %s", gai_strerror(ai_result));
        }

	return (aitop);
#else
	assert(0);
	return NULL; // XXXXX Use gethostbyname, if this function is ever used.
#endif
}
#endif

static void
name_from_addr(struct sockaddr *sa, socklen_t salen,
    char **phost, char **pport)
{
#ifdef HAVE_GETNAMEINFO
	static char ntop[NI_MAXHOST];
	static char strport[NI_MAXSERV];
	int ni_result;

	if ((ni_result = getnameinfo(sa, salen,
		ntop, sizeof(ntop), strport, sizeof(strport),
		NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
		if (ni_result == EAI_SYSTEM)
			event_err(1, "getnameinfo failed");
		else
			event_errx(1, "getnameinfo failed: %s", gai_strerror(ni_result));
	}
 
	*phost = ntop;
	*pport = strport;
#else
	// XXXX
#endif
}

/* Either connect or bind */

static int
bind_socket_ai(struct addrinfo *ai)
{
        struct linger linger;
        int fd, on = 1, r;
	int serrno;

        /* Create listen socket */
        fd = socket(AF_INET, SOCK_STREAM, 0);
        if (fd == -1) {
                event_warn("socket");
                return (-1);
        }

        if (evutil_make_socket_nonblocking(fd) < 0)
                goto out;

#ifndef WIN32
        if (fcntl(fd, F_SETFD, 1) == -1) {
                event_warn("fcntl(F_SETFD)");
                goto out;
        }
#endif

        setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, sizeof(on));
        setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on));
        linger.l_onoff = 1;
        linger.l_linger = 5;
        setsockopt(fd, SOL_SOCKET, SO_LINGER, (void *)&linger, sizeof(linger));

	r = bind(fd, ai->ai_addr, ai->ai_addrlen);
	if (r == -1)
		goto out;

	return (fd);

 out:
	serrno = EVUTIL_SOCKET_ERROR();
	EVUTIL_CLOSESOCKET(fd);
	EVUTIL_SET_SOCKET_ERROR(serrno);
	return (-1);
}

static struct addrinfo *
make_addrinfo(const char *address, u_short port)
{
        struct addrinfo *aitop = NULL;

#ifdef HAVE_GETADDRINFO
        struct addrinfo ai;
        char strport[NI_MAXSERV];
        int ai_result;

        memset(&ai, 0, sizeof(ai));
        ai.ai_family = AF_INET;
        ai.ai_socktype = SOCK_STREAM;
        ai.ai_flags = AI_PASSIVE;  /* turn NULL host name into INADDR_ANY */
        snprintf(strport, sizeof(strport), "%d", port);
        if ((ai_result = getaddrinfo(address, strport, &ai, &aitop)) != 0) {
                if ( ai_result == EAI_SYSTEM )
                        event_warn("getaddrinfo");
                else
                        event_warnx("getaddrinfo: %s", gai_strerror(ai_result));
		return (NULL);
        }
#else
	static int cur;
	static struct addrinfo ai[2]; /* We will be returning the address of some of this memory so it has to last even after this call. */
	if (++cur == 2) cur = 0;   /* allow calling this function twice */

	if (fake_getaddrinfo(address, &ai[cur]) < 0) {
		event_warn("fake_getaddrinfo");
		return (NULL);
	}
	aitop = &ai[cur];
	((struct sockaddr_in *) aitop->ai_addr)->sin_port = htons(port);
#endif

	return (aitop);
}

static int
bind_socket(const char *address, u_short port)
{
	int fd;
	struct addrinfo *aitop = make_addrinfo(address, port);

	if (aitop == NULL)
		return (-1);

	fd = bind_socket_ai(aitop);

#ifdef HAVE_GETADDRINFO
	freeaddrinfo(aitop);
#else
	fake_freeaddrinfo(aitop);
#endif

	return (fd);
}

static int
socket_connect(int fd, const char *address, unsigned short port)
{
	struct addrinfo *ai = make_addrinfo(address, port);
	int res = -1;

	if (ai == NULL) {
		event_debug(("%s: make_addrinfo: \"%s:%d\"",
			__func__, address, port));
		return (-1);
	}

	if (connect(fd, ai->ai_addr, ai->ai_addrlen) == -1) {
#ifdef WIN32
		int tmp_error = WSAGetLastError();
		if (tmp_error != WSAEWOULDBLOCK && tmp_error != WSAEINVAL &&
		    tmp_error != WSAEINPROGRESS) {
			goto out;
		}
#else
		if (errno != EINPROGRESS) {
			goto out;
		}
#endif
	}

	/* everything is fine */
	res = 0;

out:
#ifdef HAVE_GETADDRINFO
	freeaddrinfo(ai);
#else
	fake_freeaddrinfo(ai);
#endif

	return (res);
}
kc3-lang/libevent/http.c

Commit

kc3-lang/libevent /http.c
