From e0a6abbdb983849f73da5047849a7ae7f3005c48 Mon Sep 17 00:00:00 2001
From: schmonz <schmonz>
Date: Wed, 22 Apr 2009 04:48:13 +0000
Subject: Add DJB's patch to fix the axfrdns bug reported by Matthew Dempsky,
 described here:

http://article.gmane.org/gmane.network.djbdns/13864

Add mutually exclusive options, both by Jeff King, to address the
dnscache poisoning weaknesses described in CVE-2008-4392:

* "djbdns-qmerge1" (from http://www.your.org/dnscache/)
* "djbdns-qmerge2" (from http://article.gmane.org/gmane.network.djbdns/13965)

Both options are included because qmerge1 is better tested but has
known shortcomings, while qmerge2 is probably more correct but (as
yet) less well tested.

Bump PKGREVISION.
---
 net/djbdns/files/patch-qmerge2 | 254 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 254 insertions(+)
 create mode 100644 net/djbdns/files/patch-qmerge2

(limited to 'net/djbdns/files')

diff --git a/net/djbdns/files/patch-qmerge2 b/net/djbdns/files/patch-qmerge2
new file mode 100644
index 00000000000..c78e2d1a126
--- /dev/null
+++ b/net/djbdns/files/patch-qmerge2
@@ -0,0 +1,254 @@
+--- clients.h.orig	2009-04-21 23:43:02.000000000 -0400
++++ clients.h
+@@ -0,0 +1,7 @@
++#ifndef CLIENTS_H
++#define CLIENTS_H
++
++#define MAXUDP 200
++#define MAXTCP 20
++
++#endif /* CLIENTS_H */
+--- dns.h.orig	2001-02-11 16:11:45.000000000 -0500
++++ dns.h
+@@ -4,6 +4,7 @@
+ #include "stralloc.h"
+ #include "iopause.h"
+ #include "taia.h"
++#include "clients.h"
+ 
+ #define DNS_C_IN "\0\1"
+ #define DNS_C_ANY "\0\377"
+@@ -37,8 +38,14 @@ struct dns_transmit {
+   const char *servers;
+   char localip[4];
+   char qtype[2];
++  struct dns_transmit *master;
++  struct dns_transmit *slaves[MAXUDP];
++  int nslaves;
+ } ;
+ 
++extern void dns_enable_merge(void (*logger)(const char *, const char *,
++      const char *));
++
+ extern void dns_random_init(const char *);
+ extern unsigned int dns_random(unsigned int);
+ 
+--- dns_transmit.c.orig	2001-02-11 16:11:45.000000000 -0500
++++ dns_transmit.c
+@@ -7,6 +7,61 @@
+ #include "byte.h"
+ #include "uint16.h"
+ #include "dns.h"
++#include "strerr.h"
++
++static int merge_enable;
++static void (*merge_logger)(const char *, const char *, const char *);
++void dns_enable_merge(void (*f)(const char *, const char *, const char *))
++{
++  merge_enable = 1;
++  merge_logger = f;
++}
++
++static int merge_equal(struct dns_transmit *a, struct dns_transmit *b)
++{
++  const char *ip1 = a->servers + 4 * a->curserver;
++  const char *ip2 = b->servers + 4 * b->curserver;
++  return
++    byte_equal(ip1, 4, ip2) &&
++    byte_equal(a->qtype, 2, b->qtype) &&
++    dns_domain_equal(a->query + 14, b->query + 14);
++}
++
++struct dns_transmit *inprogress[MAXUDP];
++
++static int try_merge(struct dns_transmit *d)
++{
++  int i;
++  for (i = 0; i < MAXUDP; i++) {
++    if (!inprogress[i]) continue;
++    if (!merge_equal(d, inprogress[i])) continue;
++    d->master = inprogress[i];
++    inprogress[i]->slaves[inprogress[i]->nslaves++] = d;
++    return 1;
++  }
++  return 0;
++}
++
++static void register_inprogress(struct dns_transmit *d)
++{
++  int i;
++  for (i = 0; i < MAXUDP; i++) {
++    if (!inprogress[i]) {
++      inprogress[i] = d;
++      return;
++    }
++  }
++  strerr_die1x(100, "BUG: out of inprogress slots");
++}
++
++static void unregister_inprogress(struct dns_transmit *d)
++{
++  int i;
++  for (i = 0; i < MAXUDP; i++) {
++    if (inprogress[i] == d)
++      inprogress[i] = 0;
++  }
++}
+ 
+ static int serverwantstcp(const char *buf,unsigned int len)
+ {
+@@ -59,8 +114,28 @@ static void packetfree(struct dns_transm
+   d->packet = 0;
+ }
+ 
++static void mergefree(struct dns_transmit *d)
++{
++  int i;
++  if (merge_enable)
++    unregister_inprogress(d);
++  /* unregister us from our master */
++  if (d->master) {
++    for (i = 0; i < d->master->nslaves; i++)
++      if (d->master->slaves[i] == d)
++        d->master->slaves[i] = 0;
++  }
++  /* and unregister all of our slaves from us */
++  for (i = 0; i < d->nslaves; i++) {
++    if (d->slaves[i])
++      d->slaves[i]->master = NULL;
++  }
++  d->nslaves = 0;
++}
++
+ static void queryfree(struct dns_transmit *d)
+ {
++  mergefree(d);
+   if (!d->query) return;
+   alloc_free(d->query);
+   d->query = 0;
+@@ -99,11 +174,18 @@ static int thisudp(struct dns_transmit *
+   const char *ip;
+ 
+   socketfree(d);
++  mergefree(d);
+ 
+   while (d->udploop < 4) {
+     for (;d->curserver < 16;++d->curserver) {
+       ip = d->servers + 4 * d->curserver;
+       if (byte_diff(ip,4,"\0\0\0\0")) {
++        if (merge_enable && try_merge(d)) {
++          if (merge_logger)
++            merge_logger(ip, d->qtype, d->query + 14);
++          return 0;
++        }
++
+ 	d->query[2] = dns_random(256);
+ 	d->query[3] = dns_random(256);
+   
+@@ -118,6 +200,8 @@ static int thisudp(struct dns_transmit *
+             taia_uint(&d->deadline,timeouts[d->udploop]);
+             taia_add(&d->deadline,&d->deadline,&now);
+             d->tcpstate = 0;
++            if (merge_enable)
++              register_inprogress(d);
+             return 0;
+           }
+   
+@@ -226,8 +310,12 @@ void dns_transmit_io(struct dns_transmit
+   x->fd = d->s1 - 1;
+ 
+   switch(d->tcpstate) {
+-    case 0: case 3: case 4: case 5:
+-      x->events = IOPAUSE_READ;
++    case 0:
++      if (d->master) return;
++      if (d->packet) { taia_now(deadline); return; }
++      /* otherwise, fall through */
++    case 3: case 4: case 5:
++        x->events = IOPAUSE_READ;
+       break;
+     case 1: case 2:
+       x->events = IOPAUSE_WRITE;
+@@ -244,10 +332,14 @@ int dns_transmit_get(struct dns_transmit
+   unsigned char ch;
+   int r;
+   int fd;
++  int i;
+ 
+   errno = error_io;
+   fd = d->s1 - 1;
+ 
++  if (d->tcpstate == 0 && d->master) return 0;
++  if (d->tcpstate == 0 && d->packet) return 1;
++
+   if (!x->revents) {
+     if (taia_less(when,&d->deadline)) return 0;
+     errno = error_timeout;
+@@ -279,6 +371,15 @@ have sent query to curserver on UDP sock
+     d->packet = alloc(d->packetlen);
+     if (!d->packet) { dns_transmit_free(d); return -1; }
+     byte_copy(d->packet,d->packetlen,udpbuf);
++
++    for (i = 0; i < d->nslaves; i++) {
++      if (!d->slaves[i]) continue;
++      d->slaves[i]->packetlen = d->packetlen;
++      d->slaves[i]->packet = alloc(d->packetlen);
++      if (!d->slaves[i]->packet) { dns_transmit_free(d->slaves[i]); continue; }
++      byte_copy(d->slaves[i]->packet,d->packetlen,udpbuf);
++    }
++
+     queryfree(d);
+     return 1;
+   }
+--- dnscache.c.orig	2001-02-11 16:11:45.000000000 -0500
++++ dnscache.c
+@@ -54,7 +54,6 @@ uint64 numqueries = 0;
+ 
+ static int udp53;
+ 
+-#define MAXUDP 200
+ static struct udpclient {
+   struct query q;
+   struct taia start;
+@@ -131,7 +130,6 @@ void u_new(void)
+ 
+ static int tcp53;
+ 
+-#define MAXTCP 20
+ struct tcpclient {
+   struct query q;
+   struct taia start;
+@@ -435,6 +433,8 @@ int main()
+     response_hidettl();
+   if (env_get("FORWARDONLY"))
+     query_forwardonly();
++  if (env_get("MERGEQUERIES"))
++    dns_enable_merge(log_merge);
+ 
+   if (!roots_init())
+     strerr_die2sys(111,FATAL,"unable to read servers: ");
+--- log.c.orig	2001-02-11 16:11:45.000000000 -0500
++++ log.c
+@@ -150,6 +150,12 @@ void log_tx(const char *q,const char qty
+   line();
+ }
+ 
++void log_merge(const char *addr, const char qtype[2], const char *q)
++{
++  string("merge "); ip(addr); space(); logtype(qtype); space(); name(q);
++  line();
++}
++
+ void log_cachedanswer(const char *q,const char type[2])
+ {
+   string("cached "); logtype(type); space();
+--- log.h.orig	2001-02-11 16:11:45.000000000 -0500
++++ log.h
+@@ -18,6 +18,7 @@ extern void log_cachednxdomain(const cha
+ extern void log_cachedns(const char *,const char *);
+ 
+ extern void log_tx(const char *,const char *,const char *,const char *,unsigned int);
++extern void log_merge(const char *, const char *, const char *);
+ 
+ extern void log_nxdomain(const char *,const char *,unsigned int);
+ extern void log_nodata(const char *,const char *,const char *,unsigned int);
-- 
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