http.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2006, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*!
 * \file
 * \brief http server for AMI access
 *
 * \author Mark Spencer <markster@digium.com>
 *
 * This program implements a tiny http server
 * and was inspired by micro-httpd by Jef Poskanzer
 *
 * GMime http://spruce.sourceforge.net/gmime/
 *
 * \ref AstHTTP - AMI over the http protocol
 */

/*! \li \ref http.c uses the configuration file \ref http.conf
 * \addtogroup configuration_file
 */

/*! \page http.conf http.conf
 * \verbinclude http.conf.sample
 */

/*** MODULEINFO
	<support_level>core</support_level>
 ***/

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <time.h>
#include <sys/time.h>
#include <sys/stat.h>
#include <sys/signal.h>
#include <fcntl.h>

#include "asterisk/paths.h"	/* use ast_config_AST_DATA_DIR */
#include "asterisk/cli.h"
#include "asterisk/tcptls.h"
#include "asterisk/http.h"
#include "asterisk/utils.h"
#include "asterisk/strings.h"
#include "asterisk/config.h"
#include "asterisk/stringfields.h"
#include "asterisk/ast_version.h"
#include "asterisk/manager.h"
#include "asterisk/_private.h"
#include "asterisk/astobj2.h"
#include "asterisk/netsock2.h"
#include "asterisk/json.h"

#define MAX_PREFIX 80
#define DEFAULT_PORT 8088
#define DEFAULT_TLS_PORT 8089
#define DEFAULT_SESSION_LIMIT 100

/* See http.h for more information about the SSL implementation */
#if defined(HAVE_OPENSSL) && (defined(HAVE_FUNOPEN) || defined(HAVE_FOPENCOOKIE))
#define	DO_SSL	/* comment in/out if you want to support ssl */
#endif

static int session_limit = DEFAULT_SESSION_LIMIT;
static int session_count = 0;

static struct ast_tls_config http_tls_cfg;

static void *httpd_helper_thread(void *arg);

/*!
 * we have up to two accepting threads, one for http, one for https
 */
static struct ast_tcptls_session_args http_desc = {
	.accept_fd = -1,
	.master = AST_PTHREADT_NULL,
	.tls_cfg = NULL,
	.poll_timeout = -1,
	.name = "http server",
	.accept_fn = ast_tcptls_server_root,
	.worker_fn = httpd_helper_thread,
};

static struct ast_tcptls_session_args https_desc = {
	.accept_fd = -1,
	.master = AST_PTHREADT_NULL,
	.tls_cfg = &http_tls_cfg,
	.poll_timeout = -1,
	.name = "https server",
	.accept_fn = ast_tcptls_server_root,
	.worker_fn = httpd_helper_thread,
};

static AST_RWLIST_HEAD_STATIC(uris, ast_http_uri);	/*!< list of supported handlers */

/* all valid URIs must be prepended by the string in prefix. */
static char prefix[MAX_PREFIX];
static int enablestatic;

/*! \brief Limit the kinds of files we're willing to serve up */
static struct {
	const char *ext;
	const char *mtype;
} mimetypes[] = {
	{ "png", "image/png" },
	{ "xml", "text/xml" },
	{ "jpg", "image/jpeg" },
	{ "js", "application/x-javascript" },
	{ "wav", "audio/x-wav" },
	{ "mp3", "audio/mpeg" },
	{ "svg", "image/svg+xml" },
	{ "svgz", "image/svg+xml" },
	{ "gif", "image/gif" },
	{ "html", "text/html" },
	{ "htm", "text/html" },
	{ "css", "text/css" },
	{ "cnf", "text/plain" },
	{ "cfg", "text/plain" },
	{ "bin", "application/octet-stream" },
	{ "sbn", "application/octet-stream" },
	{ "ld", "application/octet-stream" },
};

struct http_uri_redirect {
	AST_LIST_ENTRY(http_uri_redirect) entry;
	char *dest;
	char target[0];
};

static AST_RWLIST_HEAD_STATIC(uri_redirects, http_uri_redirect);

static const struct ast_cfhttp_methods_text {
	enum ast_http_method method;
	const char *text;
} ast_http_methods_text[] = {
	{ AST_HTTP_UNKNOWN,     "UNKNOWN" },
	{ AST_HTTP_GET,         "GET" },
	{ AST_HTTP_POST,        "POST" },
	{ AST_HTTP_HEAD,        "HEAD" },
	{ AST_HTTP_PUT,         "PUT" },
	{ AST_HTTP_DELETE,      "DELETE" },
	{ AST_HTTP_OPTIONS,     "OPTIONS" },
};

const char *ast_get_http_method(enum ast_http_method method)
{
	int x;

	for (x = 0; x < ARRAY_LEN(ast_http_methods_text); x++) {
		if (ast_http_methods_text[x].method == method) {
			return ast_http_methods_text[x].text;
		}
	}

	return NULL;
}

const char *ast_http_ftype2mtype(const char *ftype)
{
	int x;

	if (ftype) {
		for (x = 0; x < ARRAY_LEN(mimetypes); x++) {
			if (!strcasecmp(ftype, mimetypes[x].ext)) {
				return mimetypes[x].mtype;
			}
		}
	}
	return NULL;
}

uint32_t ast_http_manid_from_vars(struct ast_variable *headers)
{
	uint32_t mngid = 0;
	struct ast_variable *v, *cookies;

	cookies = ast_http_get_cookies(headers);
	for (v = cookies; v; v = v->next) {
		if (!strcasecmp(v->name, "mansession_id")) {
			sscanf(v->value, "%30x", &mngid);
			break;
		}
	}
	ast_variables_destroy(cookies);
	return mngid;
}

void ast_http_prefix(char *buf, int len)
{
	if (buf) {
		ast_copy_string(buf, prefix, len);
	}
}

static int static_callback(struct ast_tcptls_session_instance *ser,
	const struct ast_http_uri *urih, const char *uri,
	enum ast_http_method method, struct ast_variable *get_vars,
	struct ast_variable *headers)
{
	char *path;
	const char *ftype;
	const char *mtype;
	char wkspace[80];
	struct stat st;
	int len;
	int fd;
	struct ast_str *http_header;
	struct timeval tv;
	struct ast_tm tm;
	char timebuf[80], etag[23];
	struct ast_variable *v;
	int not_modified = 0;

	if (method != AST_HTTP_GET && method != AST_HTTP_HEAD) {
		ast_http_error(ser, 501, "Not Implemented", "Attempt to use unimplemented / unsupported method");
		return -1;
	}

	/* Yuck.  I'm not really sold on this, but if you don't deliver static content it makes your configuration
	   substantially more challenging, but this seems like a rather irritating feature creep on Asterisk. */
	if (!enablestatic || ast_strlen_zero(uri)) {
		goto out403;
	}

	/* Disallow any funny filenames at all (checking first character only??) */
	if ((uri[0] < 33) || strchr("./|~@#$%^&*() \t", uri[0])) {
		goto out403;
	}

	if (strstr(uri, "/..")) {
		goto out403;
	}

	if ((ftype = strrchr(uri, '.'))) {
		ftype++;
	}

	if (!(mtype = ast_http_ftype2mtype(ftype))) {
		snprintf(wkspace, sizeof(wkspace), "text/%s", S_OR(ftype, "plain"));
		mtype = wkspace;
	}

	/* Cap maximum length */
	if ((len = strlen(uri) + strlen(ast_config_AST_DATA_DIR) + strlen("/static-http/") + 5) > 1024) {
		goto out403;
	}

	path = ast_alloca(len);
	sprintf(path, "%s/static-http/%s", ast_config_AST_DATA_DIR, uri);
	if (stat(path, &st)) {
		goto out404;
	}

	if (S_ISDIR(st.st_mode)) {
		goto out404;
	}

	if (strstr(path, "/private/") && !astman_is_authed(ast_http_manid_from_vars(headers))) {
		goto out403;
	}

	fd = open(path, O_RDONLY);
	if (fd < 0) {
		goto out403;
	}

	/* make "Etag:" http header value */
	snprintf(etag, sizeof(etag), "\"%ld\"", (long)st.st_mtime);

	/* make "Last-Modified:" http header value */
	tv.tv_sec = st.st_mtime;
	tv.tv_usec = 0;
	ast_strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT", ast_localtime(&tv, &tm, "GMT"));

	/* check received "If-None-Match" request header and Etag value for file */
	for (v = headers; v; v = v->next) {
		if (!strcasecmp(v->name, "If-None-Match")) {
			if (!strcasecmp(v->value, etag)) {
				not_modified = 1;
			}
			break;
		}
	}

	if ( (http_header = ast_str_create(255)) == NULL) {
		close(fd);
		return -1;
	}

	ast_str_set(&http_header, 0, "Content-type: %s\r\n"
		"ETag: %s\r\n"
		"Last-Modified: %s\r\n",
		mtype,
		etag,
		timebuf);

	/* ast_http_send() frees http_header, so we don't need to do it before returning */
	if (not_modified) {
		ast_http_send(ser, method, 304, "Not Modified", http_header, NULL, 0, 1);
	} else {
		ast_http_send(ser, method, 200, NULL, http_header, NULL, fd, 1); /* static content flag is set */
	}
	close(fd);
	return 0;

out404:
	ast_http_error(ser, 404, "Not Found", "The requested URL was not found on this server.");
	return -1;

out403:
	ast_http_error(ser, 403, "Access Denied", "You do not have permission to access the requested URL.");
	return -1;
}

static int httpstatus_callback(struct ast_tcptls_session_instance *ser,
	const struct ast_http_uri *urih, const char *uri,
	enum ast_http_method method, struct ast_variable *get_vars,
	struct ast_variable *headers)
{
	struct ast_str *out;
	struct ast_variable *v, *cookies = NULL;

	if (method != AST_HTTP_GET && method != AST_HTTP_HEAD) {
		ast_http_error(ser, 501, "Not Implemented", "Attempt to use unimplemented / unsupported method");
		return -1;
	}

	if ( (out = ast_str_create(512)) == NULL) {
		return -1;
	}

	ast_str_append(&out, 0,
		"<title>Asterisk HTTP Status</title>\r\n"
		"<body bgcolor=\"#ffffff\">\r\n"
		"<table bgcolor=\"#f1f1f1\" align=\"center\"><tr><td bgcolor=\"#e0e0ff\" colspan=\"2\" width=\"500\">\r\n"
		"<h2>&nbsp;&nbsp;Asterisk&trade; HTTP Status</h2></td></tr>\r\n");

	ast_str_append(&out, 0, "<tr><td><i>Prefix</i></td><td><b>%s</b></td></tr>\r\n", prefix);
	ast_str_append(&out, 0, "<tr><td><i>Bind Address</i></td><td><b>%s</b></td></tr>\r\n",
		       ast_sockaddr_stringify_addr(&http_desc.old_address));
	ast_str_append(&out, 0, "<tr><td><i>Bind Port</i></td><td><b>%s</b></td></tr>\r\n",
		       ast_sockaddr_stringify_port(&http_desc.old_address));
	if (http_tls_cfg.enabled) {
		ast_str_append(&out, 0, "<tr><td><i>SSL Bind Port</i></td><td><b>%s</b></td></tr>\r\n",
			       ast_sockaddr_stringify_port(&https_desc.old_address));
	}
	ast_str_append(&out, 0, "<tr><td colspan=\"2\"><hr></td></tr>\r\n");
	for (v = get_vars; v; v = v->next) {
		ast_str_append(&out, 0, "<tr><td><i>Submitted GET Variable '%s'</i></td><td>%s</td></tr>\r\n", v->name, v->value);
	}
	ast_str_append(&out, 0, "<tr><td colspan=\"2\"><hr></td></tr>\r\n");

	cookies = ast_http_get_cookies(headers);
	for (v = cookies; v; v = v->next) {
		ast_str_append(&out, 0, "<tr><td><i>Cookie '%s'</i></td><td>%s</td></tr>\r\n", v->name, v->value);
	}
	ast_variables_destroy(cookies);

	ast_str_append(&out, 0, "</table><center><font size=\"-1\"><i>Asterisk and Digium are registered trademarks of Digium, Inc.</i></font></center></body>\r\n");
	ast_http_send(ser, method, 200, NULL, NULL, out, 0, 0);
	return 0;
}

static struct ast_http_uri statusuri = {
	.callback = httpstatus_callback,
	.description = "Asterisk HTTP General Status",
	.uri = "httpstatus",
	.has_subtree = 0,
	.data = NULL,
	.key = __FILE__,
};

static struct ast_http_uri staticuri = {
	.callback = static_callback,
	.description = "Asterisk HTTP Static Delivery",
	.uri = "static",
	.has_subtree = 1,
	.data = NULL,
	.key= __FILE__,
};


/* send http/1.1 response */
/* free content variable and close socket*/
void ast_http_send(struct ast_tcptls_session_instance *ser,
	enum ast_http_method method, int status_code, const char *status_title,
	struct ast_str *http_header, struct ast_str *out, const int fd,
	unsigned int static_content)
{
	struct timeval now = ast_tvnow();
	struct ast_tm tm;
	char timebuf[80];
	int content_length = 0;

	if (!ser || 0 == ser->f) {
		return;
	}

	ast_strftime(timebuf, sizeof(timebuf), "%a, %d %b %Y %H:%M:%S GMT", ast_localtime(&now, &tm, "GMT"));

	/* calc content length */
	if (out) {
		content_length += ast_str_strlen(out);
	}

	if (fd) {
		content_length += lseek(fd, 0, SEEK_END);
		lseek(fd, 0, SEEK_SET);
	}

	/* send http header */
	fprintf(ser->f, "HTTP/1.1 %d %s\r\n"
		"Server: Asterisk/%s\r\n"
		"Date: %s\r\n"
		"Connection: close\r\n"
		"%s"
		"Content-Length: %d\r\n"
		"%s"
		"\r\n",
		status_code, status_title ? status_title : "OK",
		ast_get_version(),
		timebuf,
		static_content ? "" : "Cache-Control: no-cache, no-store\r\n",
		content_length,
		http_header ? ast_str_buffer(http_header) : ""
		);

	/* send content */
	if (method != AST_HTTP_HEAD || status_code >= 400) {
		if (content_length) {
			if (fwrite(ast_str_buffer(out), content_length, 1, ser->f) != 1) {
				ast_log(LOG_ERROR, "fwrite() failed: %s\n", strerror(errno));
			}
		}

		if (fd) {
			char buf[256];
			int len;
			while ((len = read(fd, buf, sizeof(buf))) > 0) {
				if (fwrite(buf, len, 1, ser->f) != 1) {
					ast_log(LOG_WARNING, "fwrite() failed: %s\n", strerror(errno));
					break;
				}
			}
		}
	}

	if (http_header) {
		ast_free(http_header);
	}
	if (out) {
		ast_free(out);
	}

	ast_tcptls_close_session_file(ser);
	return;
}

/* Send http "401 Unauthorized" responce and close socket*/
void ast_http_auth(struct ast_tcptls_session_instance *ser, const char *realm,
	const unsigned long nonce, const unsigned long opaque, int stale,
	const char *text)
{
	struct ast_str *http_headers = ast_str_create(128);
	struct ast_str *out = ast_str_create(512);

	if (!http_headers || !out) {
		ast_free(http_headers);
		ast_free(out);
		return;
	}

	ast_str_set(&http_headers, 0,
		"WWW-authenticate: Digest algorithm=MD5, realm=\"%s\", nonce=\"%08lx\", qop=\"auth\", opaque=\"%08lx\"%s\r\n"
		"Content-type: text/html\r\n",
		realm ? realm : "Asterisk",
		nonce,
		opaque,
		stale ? ", stale=true" : "");

	ast_str_set(&out, 0,
		"<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
		"<html><head>\r\n"
		"<title>401 Unauthorized</title>\r\n"
		"</head><body>\r\n"
		"<h1>401 Unauthorized</h1>\r\n"
		"<p>%s</p>\r\n"
		"<hr />\r\n"
		"<address>Asterisk Server</address>\r\n"
		"</body></html>\r\n",
		text ? text : "");

	ast_http_send(ser, AST_HTTP_UNKNOWN, 401, "Unauthorized", http_headers, out, 0, 0);
	return;
}

/* send http error response and close socket*/
void ast_http_error(struct ast_tcptls_session_instance *ser, int status_code, const char *status_title, const char *text)
{
	struct ast_str *http_headers = ast_str_create(40);
	struct ast_str *out = ast_str_create(256);

	if (!http_headers || !out) {
		ast_free(http_headers);
		ast_free(out);
		return;
	}

	ast_str_set(&http_headers, 0, "Content-type: text/html\r\n");

	ast_str_set(&out, 0,
		"<!DOCTYPE HTML PUBLIC \"-//IETF//DTD HTML 2.0//EN\">\r\n"
		"<html><head>\r\n"
		"<title>%d %s</title>\r\n"
		"</head><body>\r\n"
		"<h1>%s</h1>\r\n"
		"<p>%s</p>\r\n"
		"<hr />\r\n"
		"<address>Asterisk Server</address>\r\n"
		"</body></html>\r\n",
			status_code, status_title, status_title, text);

	ast_http_send(ser, AST_HTTP_UNKNOWN, status_code, status_title, http_headers, out, 0, 0);
	return;
}

/*! \brief
 * Link the new uri into the list.
 *
 * They are sorted by length of
 * the string, not alphabetically. Duplicate entries are not replaced,
 * but the insertion order (using <= and not just <) makes sure that
 * more recent insertions hide older ones.
 * On a lookup, we just scan the list and stop at the first matching entry.
 */
int ast_http_uri_link(struct ast_http_uri *urih)
{
	struct ast_http_uri *uri;
	int len = strlen(urih->uri);

	AST_RWLIST_WRLOCK(&uris);

	if ( AST_RWLIST_EMPTY(&uris) || strlen(AST_RWLIST_FIRST(&uris)->uri) <= len ) {
		AST_RWLIST_INSERT_HEAD(&uris, urih, entry);
		AST_RWLIST_UNLOCK(&uris);
		return 0;
	}

	AST_RWLIST_TRAVERSE(&uris, uri, entry) {
		if (AST_RWLIST_NEXT(uri, entry) &&
			strlen(AST_RWLIST_NEXT(uri, entry)->uri) <= len) {
			AST_RWLIST_INSERT_AFTER(&uris, uri, urih, entry);
			AST_RWLIST_UNLOCK(&uris);

			return 0;
		}
	}

	AST_RWLIST_INSERT_TAIL(&uris, urih, entry);

	AST_RWLIST_UNLOCK(&uris);

	return 0;
}

void ast_http_uri_unlink(struct ast_http_uri *urih)
{
	AST_RWLIST_WRLOCK(&uris);
	AST_RWLIST_REMOVE(&uris, urih, entry);
	AST_RWLIST_UNLOCK(&uris);
}

void ast_http_uri_unlink_all_with_key(const char *key)
{
	struct ast_http_uri *urih;
	AST_RWLIST_WRLOCK(&uris);
	AST_RWLIST_TRAVERSE_SAFE_BEGIN(&uris, urih, entry) {
		if (!strcmp(urih->key, key)) {
			AST_RWLIST_REMOVE_CURRENT(entry);
			if (urih->dmallocd) {
				ast_free(urih->data);
			}
			if (urih->mallocd) {
				ast_free(urih);
			}
		}
	}
	AST_RWLIST_TRAVERSE_SAFE_END;
	AST_RWLIST_UNLOCK(&uris);
}

#define MAX_POST_CONTENT 1025

/*!
 * \brief Retrieves the header with the given field name.
 *
 * \param headers Headers to search.
 * \param field_name Name of the header to find.
 * \return Associated header value.
 * \return \c NULL if header is not present.
 */
static const char *get_header(struct ast_variable *headers,
	const char *field_name)
{
	struct ast_variable *v;

	for (v = headers; v; v = v->next) {
		if (!strcasecmp(v->name, field_name)) {
			return v->value;
		}
	}
	return NULL;
}

/*!
 * \brief Retrieves the content type specified in the "Content-Type" header.
 *
 * This function only returns the "type/subtype" and any trailing parameter is
 * not included.
 *
 * \note the return value is an allocated string that needs to be freed.
 *
 * \retval the content type/subtype or NULL if the header is not found.
 */
static char *get_content_type(struct ast_variable *headers)
{
	const char *content_type = get_header(headers, "Content-Type");
	const char *param;
	size_t size;

	if (!content_type) {
		return NULL;
	}

	param = strchr(content_type, ';');
	size = param ? param - content_type : strlen(content_type);

	return ast_strndup(content_type, size);
}

/*!
 * \brief Returns the value of the Content-Length header.
 *
 * \param headers HTTP headers.
 * \return Value of the Content-Length header.
 * \return 0 if header is not present, or is invalid.
 */
static int get_content_length(struct ast_variable *headers)
{
	const char *content_length = get_header(headers, "Content-Length");

	if (!content_length) {
		/* Missing content length; assume zero */
		return 0;
	}

	/* atoi() will return 0 for invalid inputs, which is good enough for
	 * the HTTP parsing. */
	return atoi(content_length);
}

/*!
 * \brief Returns the value of the Transfer-Encoding header.
 *
 * \param headers HTTP headers.
 * \return Value of the Transfer-Encoding header.
 * \return 0 if header is not present, or is invalid.
 */
static const char *get_transfer_encoding(struct ast_variable *headers)
{
	return get_header(headers, "Transfer-Encoding");
}

/*!
 * \brief decode chunked mode hexadecimal value
 *
 * \param s string to decode
 * \param len length of string
 * \return integer value or -1 for decode error
 */
static int chunked_atoh(const char *s, int len)
{
	int value = 0;
	char c;

	if (*s < '0') {
		/* zero value must be 0\n not just \n */
		return -1;
	}

	while (len--)
	{
		if (*s == '\x0D') {
			return value;
		}
		value <<= 4;
		c = *s++;
		if (c >= '0' && c <= '9') {
			value += c - '0';
			continue;
		}
		if (c >= 'a' && c <= 'f') {
			value += 10 + c - 'a';
			continue;
		}
		if (c >= 'A' && c <= 'F') {
			value += 10 + c - 'A';
			continue;
		}
		/* invalid character */
		return -1;
	}
	/* end of string */
	return -1;
}

/*!
 * \brief Returns the contents (body) of the HTTP request
 *
 * \param return_length ptr to int that returns content length
 * \param aser HTTP TCP/TLS session object
 * \param headers List of HTTP headers
 * \return ptr to content (zero terminated) or NULL on failure
 * \note Since returned ptr is malloc'd, it should be free'd by caller
 */
static char *ast_http_get_contents(int *return_length,
	struct ast_tcptls_session_instance *ser, struct ast_variable *headers)
{
	const char *transfer_encoding;
	int res;
	int content_length = 0;
	int chunk_length;
	char chunk_header[8];
	int bufsize = 250;
	char *buf;

	transfer_encoding = get_transfer_encoding(headers);

	if (ast_strlen_zero(transfer_encoding) ||
		strcasecmp(transfer_encoding, "chunked") != 0) {
		/* handle regular non-chunked content */
		content_length = get_content_length(headers);
		if (content_length <= 0) {
			/* no content - not an error */
			return NULL;
		}
		if (content_length > MAX_POST_CONTENT - 1) {
			ast_log(LOG_WARNING,
				"Excessively long HTTP content. (%d > %d)\n",
				content_length, MAX_POST_CONTENT);
			errno = EFBIG;
			return NULL;
		}
		buf = ast_malloc(content_length + 1);
		if (!buf) {
			/* Malloc sets ENOMEM */
			return NULL;
		}
		res = fread(buf, 1, content_length, ser->f);
		if (res < content_length) {
			/* Error, distinguishable by ferror() or feof(), but neither
			 * is good. Treat either one as I/O error */
			ast_log(LOG_WARNING, "Short HTTP request body (%d < %d)\n",
				res, content_length);
			errno = EIO;
			ast_free(buf);
			return NULL;
		}
		buf[content_length] = 0;
		*return_length = content_length;
		return buf;
	}

	/* pre-allocate buffer */
	buf = ast_malloc(bufsize);
	if (!buf) {
		return NULL;
	}

	/* handled chunked content */
	do {
		/* get the line of hexadecimal giving chunk size */
		if (!fgets(chunk_header, sizeof(chunk_header), ser->f)) {
			ast_log(LOG_WARNING,
				"Short HTTP read of chunked header\n");
			errno = EIO;
			ast_free(buf);
			return NULL;
		}
		chunk_length = chunked_atoh(chunk_header, sizeof(chunk_header));
		if (chunk_length < 0) {
			ast_log(LOG_WARNING, "Invalid HTTP chunk size\n");
			errno = EIO;
			ast_free(buf);
			return NULL;
		}
		if (content_length + chunk_length > MAX_POST_CONTENT - 1) {
			ast_log(LOG_WARNING,
				"Excessively long HTTP chunk. (%d + %d > %d)\n",
				content_length, chunk_length, MAX_POST_CONTENT);
			errno = EFBIG;
			ast_free(buf);
			return NULL;
		}

		/* insure buffer is large enough +1 */
		if (content_length + chunk_length >= bufsize)
		{
			bufsize *= 2;
			buf = ast_realloc(buf, bufsize);
			if (!buf) {
				return NULL;
			}
		}

		/* read the chunk */
		res = fread(buf + content_length, 1, chunk_length, ser->f);
		if (res < chunk_length) {
			ast_log(LOG_WARNING, "Short HTTP chunk read (%d < %d)\n",
				res, chunk_length);
			errno = EIO;
			ast_free(buf);
			return NULL;
		}
		content_length += chunk_length;

		/* insure the next 2 bytes are CRLF */
		res = fread(chunk_header, 1, 2, ser->f);
		if (res < 2) {
			ast_log(LOG_WARNING,
				"Short HTTP chunk sync read (%d < 2)\n", res);
			errno = EIO;
			ast_free(buf);
			return NULL;
		}
		if (chunk_header[0] != 0x0D || chunk_header[1] != 0x0A) {
			ast_log(LOG_WARNING,
				"Post HTTP chunk sync bytes wrong (%d, %d)\n",
				chunk_header[0], chunk_header[1]);
			errno = EIO;
			ast_free(buf);
			return NULL;
		}
	} while (chunk_length);

	buf[content_length] = 0;
	*return_length = content_length;
	return buf;
}

struct ast_json *ast_http_get_json(
	struct ast_tcptls_session_instance *ser, struct ast_variable *headers)
{
	int content_length = 0;
	struct ast_json *body;
	RAII_VAR(char *, buf, NULL, ast_free);
	RAII_VAR(char *, type, get_content_type(headers), ast_free);

	/* Use errno to distinguish errors from no body */
	errno = 0;

	if (ast_strlen_zero(type) || strcasecmp(type, "application/json")) {
		/* Content type is not JSON */
		return NULL;
	}

	buf = ast_http_get_contents(&content_length, ser, headers);
	if (buf == NULL) {
		/* errno already set */
		return NULL;
	}

	if (!content_length) {
		/* it is not an error to have zero content */
		return NULL;
	}

	body = ast_json_load_buf(buf, content_length, NULL);
	if (body == NULL) {
		/* Failed to parse JSON; treat as an I/O error */
		errno = EIO;
		return NULL;
	}

	return body;
}

/*
 * get post variables from client Request Entity-Body, if content type is
 * application/x-www-form-urlencoded
 */
struct ast_variable *ast_http_get_post_vars(
	struct ast_tcptls_session_instance *ser, struct ast_variable *headers)
{
	int content_length = 0;
	struct ast_variable *v, *post_vars=NULL, *prev = NULL;
	char *var, *val;
	RAII_VAR(char *, buf, NULL, ast_free_ptr);
	RAII_VAR(char *, type, get_content_type(headers), ast_free);

	/* Use errno to distinguish errors from no params */
	errno = 0;

	if (ast_strlen_zero(type) ||
	    strcasecmp(type, "application/x-www-form-urlencoded")) {
		/* Content type is not form data */
		return NULL;
	}

	buf = ast_http_get_contents(&content_length, ser, headers);
	if (buf == NULL) {
		return NULL;
	}

	while ((val = strsep(&buf, "&"))) {
		var = strsep(&val, "=");
		if (val) {
			ast_uri_decode(val, ast_uri_http_legacy);
		} else  {
			val = "";
		}
		ast_uri_decode(var, ast_uri_http_legacy);
		if ((v = ast_variable_new(var, val, ""))) {
			if (post_vars) {
				prev->next = v;
			} else {
				post_vars = v;
			}
			prev = v;
		}
	}

	return post_vars;
}

static int handle_uri(struct ast_tcptls_session_instance *ser, char *uri,
	enum ast_http_method method, struct ast_variable *headers)
{
	char *c;
	int res = -1;
	char *params = uri;
	struct ast_http_uri *urih = NULL;
	int l;
	struct ast_variable *get_vars = NULL, *v, *prev = NULL;
	struct http_uri_redirect *redirect;

	ast_debug(2, "HTTP Request URI is %s \n", uri);

	strsep(&params, "?");
	/* Extract arguments from the request and store them in variables. */
	if (params) {
		char *var, *val;

		while ((val = strsep(&params, "&"))) {
			var = strsep(&val, "=");
			if (val) {
				ast_uri_decode(val, ast_uri_http_legacy);
			} else  {
				val = "";
			}
			ast_uri_decode(var, ast_uri_http_legacy);
			if ((v = ast_variable_new(var, val, ""))) {
				if (get_vars) {
					prev->next = v;
				} else {
					get_vars = v;
				}
				prev = v;
			}
		}
	}

	AST_RWLIST_RDLOCK(&uri_redirects);
	AST_RWLIST_TRAVERSE(&uri_redirects, redirect, entry) {
		if (!strcasecmp(uri, redirect->target)) {
			struct ast_str *http_header = ast_str_create(128);
			ast_str_set(&http_header, 0, "Location: %s\r\n", redirect->dest);
			ast_http_send(ser, method, 302, "Moved Temporarily", http_header, NULL, 0, 0);

			break;
		}
	}
	AST_RWLIST_UNLOCK(&uri_redirects);
	if (redirect) {