srv_lookup: Portability fixes, handle compressed responses

srv_lookup works on cygwin and openbsd now.

Provide ns_initparse, friends, and types where they aren't provided by
platform.

Use dn_expandname instead of custom parser so compressed DNS responses
are handled correctly.

4 files changed, 309 insertions, 18 deletions

diff --git a/lib/Makefile b/lib/Makefile
index f20b3797..40c03215 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -12,7 +12,7 @@ _SRCDIR_ := $(_SRCDIR_)lib/
 endif
 
 # [SH] Program variables
-objects = arc.o base64.o $(EVENT_HANDLER) ftutil.o http_client.o ini.o json.o json_util.o md5.o misc.o oauth.o oauth2.o proxy.o sha1.o $(SSL_CLIENT) url.o xmltree.o
+objects = arc.o base64.o $(EVENT_HANDLER) ftutil.o http_client.o ini.o json.o json_util.o md5.o misc.o oauth.o oauth2.o proxy.o sha1.o $(SSL_CLIENT) url.o xmltree.o ns_parse.o
 
 LFLAGS += -r
 
diff --git a/lib/misc.c b/lib/misc.c
index 2506e291..f1da03cb 100644
--- a/lib/misc.c
+++ b/lib/misc.c
@@ -524,7 +524,7 @@ struct ns_srv_reply **srv_lookup( char *service, char *protocol, char *domain )
 	const unsigned char *buf;
 	ns_msg nsh;
 	ns_rr rr;
-	int i, n, len, size;
+	int n, len, size;
 	
 	g_snprintf( name, sizeof( name ), "_%s._%s.%s", service, protocol, domain );
 	
@@ -537,27 +537,20 @@ struct ns_srv_reply **srv_lookup( char *service, char *protocol, char *domain )
 	n = 0;
 	while( ns_parserr( &nsh, ns_s_an, n, &rr ) == 0 )
 	{
-		size = ns_rr_rdlen( rr );
+		char name[NS_MAXDNAME];
+
+		if( ns_rr_rdlen( rr ) < 7)
+		    break;
+
 		buf = ns_rr_rdata( rr );
 		
-		len = 0;
-		for( i = 6; i < size && buf[i]; i += buf[i] + 1 )
-			len += buf[i] + 1;
-		
-		if( i > size )
+		if( dn_expand(querybuf, querybuf + size, &buf[6], name, NS_MAXDNAME) == -1 )
 			break;
+
+		len = strlen(name) + 1;
 		
 		reply = g_malloc( sizeof( struct ns_srv_reply ) + len );
-		memcpy( reply->name, buf + 7, len );
-		
-		for( i = buf[6]; i < len && buf[7+i]; i += buf[7+i] + 1 )
-			reply->name[i] = '.';
-		
-		if( i > len )
-		{
-			g_free( reply );
-			break;
-		}
+		memcpy( reply->name, name, len );
 		
 		reply->prio = ( buf[0] << 8 ) | buf[1];
 		reply->weight = ( buf[2] << 8 ) | buf[3];
diff --git a/lib/misc.h b/lib/misc.h
index 674a61b6..460cce8c 100644
--- a/lib/misc.h
+++ b/lib/misc.h
@@ -37,6 +37,87 @@ struct ns_srv_reply
 	char name[];
 };
 
+#ifndef NAMESER_HAS_NS_TYPES
+
+#define NS_MAXDNAME 1025
+#define NS_INT16SZ  2
+#define NS_INT32SZ  4
+
+#define NS_GET16(s, cp) do { \
+	register const unsigned char *t_cp = (const unsigned char*)(cp); \
+	(s) = ((guint16)t_cp[0] << 8) \
+	    | ((guint16)t_cp[1]) \
+	    ; \
+	(cp) += NS_INT16SZ; \
+} while(0)
+
+#define NS_GET32(s, cp) do { \
+	register const unsigned char *t_cp = (const unsigned char*)(cp); \
+	(s) = ((guint16)t_cp[0] << 24) \
+	    | ((guint16)t_cp[1] << 16) \
+	    | ((guint16)t_cp[2] << 8) \
+	    | ((guint16)t_cp[3]) \
+	    ; \
+	(cp) += NS_INT32SZ; \
+} while(0)
+
+#define ns_rr_rdlen(rr) ((rr).rdlength + 0)
+#define ns_rr_rdata(rr) ((rr).rdata + 0)
+
+struct _ns_flagdata { int mask, shift; };
+
+typedef struct __ns_rr {
+	char name[NS_MAXDNAME];
+	guint16 type;
+	guint16 rr_class;
+	guint32 ttl;
+	guint16 rdlength;
+	const unsigned char* rdata;
+} ns_rr;
+
+typedef enum __ns_sect {
+	ns_s_qd = 0,
+	ns_s_zn = 0,
+	ns_s_an = 1,
+	ns_s_pr = 1,
+	ns_s_ns = 2,
+	ns_s_ud = 2,
+	ns_s_ar = 3,
+	ns_s_max =4
+} ns_sect;
+
+typedef struct __ns_msg
+{
+	const unsigned char* _msg;
+	const unsigned char* _eom;
+	guint16 _id;
+	guint16 _flags;
+	guint16 _counts[ns_s_max];
+	const unsigned char* _sections[ns_s_max];
+	ns_sect _sect;
+	int _rrnum;
+	const unsigned char* _msg_ptr;
+} ns_msg;
+
+typedef enum __ns_class {
+	ns_c_invalid = 0,
+	ns_c_in = 1,
+	ns_c_2 = 2,
+	ns_c_chaos = 3,
+	ns_c_hs = 4,
+	ns_c_none = 254,
+	ns_c_any = 255,
+	ns_c_max = 65536
+} ns_class;
+
+
+/* TODO : fill out the rest */
+typedef enum __ns_type {
+	ns_t_srv = 33
+} ns_type;
+
+#endif /* NAMESER_HAS_NS_INITPARSE */
+
 G_MODULE_EXPORT void strip_linefeed( gchar *text );
 G_MODULE_EXPORT char *add_cr( char *text );
 G_MODULE_EXPORT char *strip_newlines(char *source);
diff --git a/lib/ns_parse.c b/lib/ns_parse.c
new file mode 100644
index 00000000..ba45d513
--- /dev/null
+++ b/lib/ns_parse.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
+ * Copyright (c) 1996,1999 by Internet Software Consortium.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+ * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "bitlbee.h"
+
+#ifndef lint
+static const char rcsid[] = "$Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp $";
+#endif
+
+#ifdef HAVE_RESOLV_A
+#ifndef HAVE_RESOLV_A_WITH_NS
+/* Import. */
+
+
+#include <sys/types.h>
+
+#include <netinet/in.h>
+#include <arpa/nameser.h>
+
+#include <errno.h>
+#include <resolv.h>
+#include <string.h>
+
+
+/* Forward. */
+
+static void	setsection(ns_msg *msg, ns_sect sect);
+
+/* Macros. */
+
+#if !defined(SOLARIS2) || defined(__COVERITY__)
+#define RETERR(err) do { errno = (err); return (-1); } while (0)
+#else
+#define RETERR(err) \
+	do { errno = (err); if (errno == errno) return (-1); } while (0)
+#endif
+
+#define PARSE_FMT_PRESO 0	/* Parse using presentation-format names */
+#define PARSE_FMT_WIRE 1	/* Parse using network-format names */
+
+/* Public. */
+
+/* These need to be in the same order as the nres.h:ns_flag enum. */
+struct _ns_flagdata _ns_flagdata[16] = {
+	{ 0x8000, 15 },		/*%< qr. */
+	{ 0x7800, 11 },		/*%< opcode. */
+	{ 0x0400, 10 },		/*%< aa. */
+	{ 0x0200, 9 },		/*%< tc. */
+	{ 0x0100, 8 },		/*%< rd. */
+	{ 0x0080, 7 },		/*%< ra. */
+	{ 0x0040, 6 },		/*%< z. */
+	{ 0x0020, 5 },		/*%< ad. */
+	{ 0x0010, 4 },		/*%< cd. */
+	{ 0x000f, 0 },		/*%< rcode. */
+	{ 0x0000, 0 },		/*%< expansion (1/6). */
+	{ 0x0000, 0 },		/*%< expansion (2/6). */
+	{ 0x0000, 0 },		/*%< expansion (3/6). */
+	{ 0x0000, 0 },		/*%< expansion (4/6). */
+	{ 0x0000, 0 },		/*%< expansion (5/6). */
+	{ 0x0000, 0 },		/*%< expansion (6/6). */
+};
+
+int ns_msg_getflag(ns_msg handle, int flag) {
+	return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift);
+}
+
+int
+ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) {
+	const u_char *optr = ptr;
+
+	for ((void)NULL; count > 0; count--) {
+		int b, rdlength;
+
+		b = dn_skipname(ptr, eom);
+		if (b < 0)
+			RETERR(EMSGSIZE);
+		ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/;
+		if (section != ns_s_qd) {
+			if (ptr + NS_INT32SZ + NS_INT16SZ > eom)
+				RETERR(EMSGSIZE);
+			ptr += NS_INT32SZ/*TTL*/;
+			NS_GET16(rdlength, ptr);
+			ptr += rdlength/*RData*/;
+		}
+	}
+	if (ptr > eom)
+		RETERR(EMSGSIZE);
+	return (ptr - optr);
+}
+
+int
+ns_initparse(const u_char *msg, int msglen, ns_msg *handle) {
+	const u_char *eom = msg + msglen;
+	int i;
+
+	handle->_msg = msg;
+	handle->_eom = eom;
+	if (msg + NS_INT16SZ > eom)
+		RETERR(EMSGSIZE);
+	NS_GET16(handle->_id, msg);
+	if (msg + NS_INT16SZ > eom)
+		RETERR(EMSGSIZE);
+	NS_GET16(handle->_flags, msg);
+	for (i = 0; i < ns_s_max; i++) {
+		if (msg + NS_INT16SZ > eom)
+			RETERR(EMSGSIZE);
+		NS_GET16(handle->_counts[i], msg);
+	}
+	for (i = 0; i < ns_s_max; i++)
+		if (handle->_counts[i] == 0)
+			handle->_sections[i] = NULL;
+		else {
+			int b = ns_skiprr(msg, eom, (ns_sect)i,
+					  handle->_counts[i]);
+
+			if (b < 0)
+				return (-1);
+			handle->_sections[i] = msg;
+			msg += b;
+		}
+	if (msg != eom)
+		RETERR(EMSGSIZE);
+	setsection(handle, ns_s_max);
+	return (0);
+}
+
+int
+ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) {
+	int b;
+	int tmp;
+
+	/* Make section right. */
+	tmp = section;
+	if (tmp < 0 || section >= ns_s_max)
+		RETERR(ENODEV);
+	if (section != handle->_sect)
+		setsection(handle, section);
+
+	/* Make rrnum right. */
+	if (rrnum == -1)
+		rrnum = handle->_rrnum;
+	if (rrnum < 0 || rrnum >= handle->_counts[(int)section])
+		RETERR(ENODEV);
+	if (rrnum < handle->_rrnum)
+		setsection(handle, section);
+	if (rrnum > handle->_rrnum) {
+		b = ns_skiprr(handle->_msg_ptr, handle->_eom, section,
+			      rrnum - handle->_rrnum);
+
+		if (b < 0)
+			return (-1);
+		handle->_msg_ptr += b;
+		handle->_rrnum = rrnum;
+	}
+
+	/* Do the parse. */
+	b = dn_expand(handle->_msg, handle->_eom,
+		      handle->_msg_ptr, rr->name, NS_MAXDNAME);
+	if (b < 0)
+		return (-1);
+	handle->_msg_ptr += b;
+	if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom)
+		RETERR(EMSGSIZE);
+	NS_GET16(rr->type, handle->_msg_ptr);
+	NS_GET16(rr->rr_class, handle->_msg_ptr);
+	if (section == ns_s_qd) {
+		rr->ttl = 0;
+		rr->rdlength = 0;
+		rr->rdata = NULL;
+	} else {
+		if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom)
+			RETERR(EMSGSIZE);
+		NS_GET32(rr->ttl, handle->_msg_ptr);
+		NS_GET16(rr->rdlength, handle->_msg_ptr);
+		if (handle->_msg_ptr + rr->rdlength > handle->_eom)
+			RETERR(EMSGSIZE);
+		rr->rdata = handle->_msg_ptr;
+		handle->_msg_ptr += rr->rdlength;
+	}
+	if (++handle->_rrnum > handle->_counts[(int)section])
+		setsection(handle, (ns_sect)((int)section + 1));
+
+	/* All done. */
+	return (0);
+}
+
+/* Private. */
+
+static void
+setsection(ns_msg *msg, ns_sect sect) {
+	msg->_sect = sect;
+	if (sect == ns_s_max) {
+		msg->_rrnum = -1;
+		msg->_msg_ptr = NULL;
+	} else {
+		msg->_rrnum = 0;
+		msg->_msg_ptr = msg->_sections[(int)sect];
+	}
+}
+
+/*! \file */
+#endif
+#endif