--- /dev/null
+diff -urN djbdns-1.05.org/MULTIPLEIP djbdns-1.05/MULTIPLEIP
+--- djbdns-1.05.org/MULTIPLEIP Thu Jan 1 01:00:00 1970
++++ djbdns-1.05/MULTIPLEIP Sat Apr 28 22:15:42 2001
+@@ -0,0 +1,10 @@
++
++When applied, dnscache will accept a /-delimited list of IP address in $IP
++and bind to each in turn. This allows one to have dnscache listen on, say,
++external IP 1.2.3.4 which only client group A can reach, and, say,
++internal IP 4.3.2.1 which only client group B can reach. Assuming 1.2.3.4
++and 4.3.2.1 are on the same machine, instead of running two independent
++dnscache instances on 1.2.3.4 and 4.3.2.1, one instance can bind to both
++IP's and serve queries from the shared cache. Simply put 1.2.3.4/4.3.2.1 in env/IP.
++
++http://danp.net/djbdns/patches.html
+diff -r -u djbdns+ipv6/dnscache.c djbdns-1.05/dnscache.c
+--- djbdns+ipv6/dnscache.c 2004-09-29 21:17:03.000000000 +0200
++++ djbdns-1.05/dnscache.c 2004-09-29 22:02:38.018542064 +0200
+@@ -6,6 +6,7 @@
+ #include "error.h"
+ #include "ip4.h"
+ #include "ip6.h"
++#include "str.h"
+ #include "uint16.h"
+ #include "uint64.h"
+ #include "socket.h"
+@@ -52,12 +53,20 @@
+
+
+ static char myipoutgoing[16];
+-static char myipincoming[16];
+ static char buf[1024];
+ uint64 numqueries = 0;
+
++struct interf {
++ char ip[16];
++ int udp53;
++ int tcp53;
++ iopause_fd *udp53io;
++ iopause_fd *tcp53io;
++
++ struct interf *next;
++};
+
+-static int udp53;
++struct interf *interhead = 0;
+
+ #define MAXUDP 200
+ static struct udpclient {
+@@ -65,6 +74,7 @@
+ struct taia start;
+ uint64 active; /* query number, if active; otherwise 0 */
+ iopause_fd *io;
++ int fd;
+ char ip[16];
+ uint16 port;
+ char id[2];
+@@ -84,12 +94,12 @@
+ if (!u[j].active) return;
+ response_id(u[j].id);
+ if (response_len > 512) response_tc();
+- socket_send6(udp53,response,response_len,u[j].ip,u[j].port,u[j].scope_id);
++ socket_send6(u[j].fd,response,response_len,u[j].ip,u[j].port,u[j].scope_id);
+ log_querydone(&u[j].active,response_len);
+ u[j].active = 0; --uactive;
+ }
+
+-void u_new(void)
++void u_new(int fd)
+ {
+ int j;
+ int i;
+@@ -114,8 +124,9 @@
+
+ x = u + j;
+ taia_now(&x->start);
++ x->fd=fd;
+
+- len = socket_recv6(udp53,buf,sizeof buf,x->ip,&x->port,&x->scope_id);
++ len = socket_recv6(x->fd,buf,sizeof buf,x->ip,&x->port,&x->scope_id);
+ if (len == -1) return;
+ if (len >= sizeof buf) return;
+ if (x->port < 1024) if (x->port != 53) return;
+@@ -134,8 +145,6 @@
+ }
+ }
+
+-static int tcp53;
+-
+ #define MAXTCP 20
+ struct tcpclient {
+ struct query q;
+@@ -143,6 +152,7 @@
+ struct taia timeout;
+ uint64 active; /* query number or 1, if active; otherwise 0 */
+ iopause_fd *io;
++ int fd;
+ char ip[16]; /* send response to this address */
+ uint16 port; /* send response to this port */
+ char id[2];
+@@ -272,7 +282,7 @@
+ x->state = 0;
+ }
+
+-void t_new(void)
++void t_new(int fd)
+ {
+ int i;
+ int j;
+@@ -296,8 +306,9 @@
+
+ x = t + j;
+ taia_now(&x->start);
++ x->fd=fd;
+
+- x->tcp = socket_accept6(tcp53,x->ip,&x->port,&x->scope_id);
++ x->tcp = socket_accept6(x->fd,x->ip,&x->port,&x->scope_id);
+ if (x->tcp == -1) return;
+ if (x->port < 1024) if (x->port != 53) { close(x->tcp); return; }
+ if (!okclient(x->ip)) { close(x->tcp); return; }
+@@ -310,19 +321,24 @@
+ log_tcpopen(x->ip,x->port);
+ }
+
++#define FATAL "dnscache: fatal: "
+
+-iopause_fd io[3 + MAXUDP + MAXTCP];
+-iopause_fd *udp53io;
+-iopause_fd *tcp53io;
++iopause_fd *io = 0;
++int numio;
+
+ static void doit(void)
+ {
+ int j;
+ struct taia deadline;
+ struct taia stamp;
++ struct interf *inter;
+ int iolen;
+ int r;
+
++ io = (iopause_fd *) alloc((numio + 1 + MAXUDP + MAXTCP) * sizeof(iopause_fd));
++ if (!io)
++ strerr_die2sys(111,FATAL,"unable to alloc io: ");
++
+ for (;;) {
+ taia_now(&stamp);
+ taia_uint(&deadline,120);
+@@ -330,13 +346,15 @@
+
+ iolen = 0;
+
+- udp53io = io + iolen++;
+- udp53io->fd = udp53;
+- udp53io->events = IOPAUSE_READ;
+-
+- tcp53io = io + iolen++;
+- tcp53io->fd = tcp53;
+- tcp53io->events = IOPAUSE_READ;
++ for (inter = interhead; inter != 0; inter = inter->next) {
++ inter->udp53io = io + iolen++;
++ inter->udp53io->fd = inter->udp53;
++ inter->udp53io->events = IOPAUSE_READ;
++
++ inter->tcp53io = io + iolen++;
++ inter->tcp53io->fd = inter->tcp53;
++ inter->tcp53io->events = IOPAUSE_READ;
++ }
+
+ for (j = 0;j < MAXUDP;++j)
+ if (u[j].active) {
+@@ -378,23 +396,30 @@
+ t_rw(j);
+ }
+
+- if (udp53io)
+- if (udp53io->revents)
+- u_new();
+-
+- if (tcp53io)
+- if (tcp53io->revents)
+- t_new();
+- }
++ for (inter = interhead; inter != 0; inter = inter->next) {
++ if (inter->udp53io)
++ if (inter->udp53io->revents)
++ u_new(inter->udp53);
++
++ if (inter->tcp53io)
++ if (inter->tcp53io->revents)
++ t_new(inter->tcp53);
++ }
++ }
+ }
+
+-#define FATAL "dnscache: fatal: "
+-
+ char seed[128];
+
+ int main()
+ {
+ char *x;
++ int len;
++ int pos;
++ int oldpos;
++ char iptmp[4];
++ char iperr[IP4_FMT];
++ struct interf *inter;
++ struct interf *itmp;
+ unsigned int i, j, k;
+ unsigned long cachesize;
+ static stralloc sa = {0};
+@@ -405,31 +430,50 @@
+ x = env_get("IP");
+ if (!x)
+ strerr_die2x(111,FATAL,"$IP not set");
+- if (!ip6_scan(x,myipincoming))
+- strerr_die3x(111,FATAL,"unable to parse IP address ",x);
++ len = str_len(x);
++ numio = pos = oldpos = 0;
++ while (pos < len) {
++ if (pos) oldpos = pos + 1;
++ pos = oldpos + str_chr(x + oldpos,'/');
++ x[pos] = 0;
++ if (!str_len(x + oldpos)) continue;
++
++ if (!ip6_scan(x + oldpos,iptmp))
++ strerr_die3x(111,FATAL,"unable to parse IP address ",x + oldpos);
++
++ inter = (struct interf *) alloc(sizeof(struct interf));
++
++ if (interhead == 0) interhead = inter;
++ else if (interhead->next == 0) interhead->next = inter;
++ else {
++ for (itmp = interhead; itmp->next != 0; itmp = itmp->next);
++ itmp->next = inter;
++ }
+
+-#if 0
+- /* if if IP is a mapped-IPv4 address, disable IPv6 functionality */
+- /* this is actually a bad idea */
+- if (ip6_isv4mapped(myipincoming))
+- noipv6 = 1;
+-#endif
+-
+- udp53 = socket_udp6();
+- if (udp53 == -1)
+- strerr_die2sys(111,FATAL,"unable to create UDP socket: ");
+- if (socket_bind6_reuse(udp53,myipincoming,53,interface) == -1)
+- strerr_die2sys(111,FATAL,"unable to bind UDP socket: ");
+-
+- tcp53 = socket_tcp6();
+- if (tcp53 == -1)
+- strerr_die2sys(111,FATAL,"unable to create TCP socket: ");
+- if (socket_bind6_reuse(tcp53,myipincoming,53,interface) == -1)
+- strerr_die2sys(111,FATAL,"unable to bind TCP socket: ");
++ inter->next = 0;
++ inter->udp53 = socket_udp6();
++ if (inter->udp53 == -1)
++ strerr_die4sys(111,FATAL,"unable to create UDP socket for IP address ",x + oldpos,": ");
++ if (socket_bind6_reuse(inter->udp53,iptmp,53,interface) == -1)
++ strerr_die4sys(111,FATAL,"unable to bind UDP socket for IP address ",x + oldpos,": ");
++
++ inter->tcp53 = socket_tcp6();
++ if (inter->tcp53 == -1)
++ strerr_die4sys(111,FATAL,"unable to create TCP socket for IP address ",x + oldpos,": ");
++ if (socket_bind6_reuse(inter->tcp53,iptmp,53,interface) == -1)
++ strerr_die4sys(111,FATAL,"unable to bind TCP socket for IP address ",x + oldpos,": ");
++
++ numio++;
++ log_listen(iptmp);
++ }
++
++ if (interhead == 0)
++ strerr_die2x(111,FATAL,"no interfaces to listen on");
+
+ droproot(FATAL);
+
+- socket_tryreservein(udp53,131072);
++ for (inter = interhead; inter != 0; inter = inter->next)
++ socket_tryreservein(inter->udp53,131072);
+
+ byte_zero(seed,sizeof seed);
+ read(0,seed,sizeof seed);
+@@ -471,8 +515,11 @@
+ if (!roots_init())
+ strerr_die2sys(111,FATAL,"unable to read servers: ");
+
+- if (socket_listen(tcp53,20) == -1)
+- strerr_die2sys(111,FATAL,"unable to listen on TCP socket: ");
++ for (inter = interhead; inter != 0; inter = inter->next)
++ if (socket_listen(inter->tcp53,20) == -1) {
++ iperr[ip4_fmt(iperr,inter->ip)] = 0;
++ strerr_die4sys(111,FATAL,"unable to listen on TCP socket for IP ",iperr,": ");
++ }
+
+ log_startup();
+ doit();
+diff -r -u djbdns+ipv6/log.c djbdns-1.05/log.c
+--- djbdns+ipv6/log.c 2004-09-29 21:17:03.000000000 +0200
++++ djbdns-1.05/log.c 2004-09-29 21:47:02.523655344 +0200
+@@ -285,3 +285,10 @@
+ number(tactive);
+ line();
+ }
++
++void log_listen(const char addr[16])
++{
++ string("listening on ");
++ ip(addr);
++ line();
++}
+diff -r -u djbdns+ipv6/log.h djbdns-1.05/log.h
+--- djbdns+ipv6/log.h 2001-02-11 22:11:45.000000000 +0100
++++ djbdns-1.05/log.h 2004-09-29 21:18:46.114548728 +0200
+@@ -4,6 +4,7 @@
+ #include "uint64.h"
+
+ extern void log_startup(void);
++extern void log_listen(const char *);
+
+ extern void log_query(uint64 *,const char *,unsigned int,const char *,const char *,const char *);
+ extern void log_querydrop(uint64 *);