pkstream/pkstream.c: Enable IPv6 address support.

Implement the address-helper branches for IPv6, and set the default
address family to `AF_UNSPEC'.  Also, introduce command-line switches
for limiting address resolution.

diff --git a/pkstream/pkstream.1.in b/pkstream/pkstream.1.in
index cdf8dc5ed1a3cbd4a35997cc160047b4778bcf4a..757e5cdea6301d2ebf9a6535ab385c50c016e178 100644 (file)
--- a/pkstream/pkstream.1.in
+++ b/pkstream/pkstream.1.in
@@ -37,6 +37,7 @@ pkstream \- forward UDP packets over streams
 .SH "SYNOPSIS"
 .
 .B pkstream
+.RB [ \-46 ]
 .RB [ \-l
 .IR port ]
 .RB [ \-p
@@ -97,6 +98,12 @@ version number to standard output and exits with status 0.
 .B "\-u, \-\-usage"
 Writes a brief usage summary to standard output and exits with status 0.
 .TP
+.B "\-4"
+Look up hostnames only as IPv4 addresses.
+.TP
+.B "\-6"
+Look up hostnames only as IPv6 addresses.
+.TP
 .BI "\-l, \-\-listen=" port
 Listen for connections on the given TCP
 .IR port .

diff --git a/pkstream/pkstream.c b/pkstream/pkstream.c
index f07c075b30940dcd9339ae5983a13d6501dfd301..8b2a058c316b2523bb43aa0aa402534096c001a7 100644 (file)
--- a/pkstream/pkstream.c
+++ b/pkstream/pkstream.c
@@ -61,6 +61,7 @@
 typedef union addr {
   struct sockaddr sa;
   struct sockaddr_in sin;
+  struct sockaddr_in6 sin6;
 } addr;
 
 DA_DECL(addr_v, addr);
@@ -107,6 +108,7 @@ static socklen_t addrsz(const addr *a)
 {
   switch (a->sa.sa_family) {
     case AF_INET: return sizeof(a->sin);
+    case AF_INET6: return sizeof(a->sin6);
     default: abort();
   }
 }
@@ -114,15 +116,21 @@ static socklen_t addrsz(const addr *a)
 static int knownafp(int af)
 {
   switch (af) {
-    case AF_INET: return (1);
+    case AF_INET: case AF_INET6: return (1);
     default: return (0);
   }
 }
 
 static int initsock(int fd, int af)
 {
+  int yes = 1;
+
   switch (af) {
     case AF_INET: break;
+    case AF_INET6:
+      if (setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &yes, sizeof(yes)))
+       return (-1);
+      break;
     default: abort();
   }
   return (0);
@@ -144,6 +152,11 @@ static int addreq(const addr *a, const addr *b)
   switch (a->sa.sa_family) {
     case AF_INET:
       return (a->sin.sin_addr.s_addr == b->sin.sin_addr.s_addr);
+    case AF_INET6:
+      return (!memcmp(a->sin6.sin6_addr.s6_addr,
+                     b->sin6.sin6_addr.s6_addr,
+                     16) &&
+             a->sin6.sin6_scope_id == b->sin6.sin6_scope_id);
     default:
       abort();
   }
@@ -157,6 +170,12 @@ static void initaddr(addr *a, int af)
       a->sin.sin_addr.s_addr = INADDR_ANY;
       a->sin.sin_port = 0;
       break;
+    case AF_INET6:
+      memset(a->sin6.sin6_addr.s6_addr, 0, 16);
+      a->sin6.sin6_port = 0;
+      a->sin6.sin6_flowinfo = 0;
+      a->sin6.sin6_scope_id = 0;
+      break;
     default:
       abort();
   }
@@ -167,6 +186,7 @@ static void initaddr(addr *a, int af)
 static void copyaddr(addr *a, const struct sockaddr *sa, unsigned f)
 {
   const struct sockaddr_in *sin;
+  const struct sockaddr_in6 *sin6;
 
   a->sa.sa_family = sa->sa_family;
   switch (sa->sa_family) {
@@ -175,6 +195,15 @@ static void copyaddr(addr *a, const struct sockaddr *sa, unsigned f)
       if (f&caf_addr) a->sin.sin_addr = sin->sin_addr;
       if (f&caf_port) a->sin.sin_port = sin->sin_port;
       break;
+    case AF_INET6:
+      sin6 = (const struct sockaddr_in6 *)sa;
+      if (f&caf_addr) {
+       a->sin6.sin6_addr = sin6->sin6_addr;
+       a->sin6.sin6_scope_id = sin6->sin6_scope_id;
+      }
+      if (f&caf_port) a->sin6.sin6_port = sin6->sin6_port;
+      /* ??? flowinfo? */
+      break;
     default:
       abort();
   }
@@ -406,7 +435,7 @@ static void parseaddr(const struct addrinfo *aihint,
 static void usage(FILE *fp)
 {
   pquis(fp,
-       "Usage: $ [-l PORT] [-b ADDR] [-p ADDR] [-c ADDR:PORT]\n\
+       "Usage: $ [-46] [-l PORT] [-b ADDR] [-p ADDR] [-c ADDR:PORT]\n\
        ADDR:PORT ADDR:PORT\n");
 }
 
@@ -425,6 +454,8 @@ Options:\n\
 -v, --version          Display version number.\n\
 -u, --usage            Display pointless usage message.\n\
 \n\
+-4, --ipv4             Restrict to IPv4 only.\n\
+-6, --ipv6             Restrict to IPv6 only.\n\
 -l, --listen=PORT      Listen for connections to TCP PORT.\n\
 -p, --peer=ADDR                Only accept connections from IP ADDR.\n\
 -b, --bind=ADDR                Bind to ADDR before connecting.\n\
@@ -443,6 +474,7 @@ int main(int argc, char *argv[])
   addr bindaddr;
   const char *connhost = 0;
   struct addrinfo aihint = { 0 }, *ai, *ailist;
+  int af = AF_UNSPEC;
   int fd = -1;
   int len = 65536;
   size_t i, n;
@@ -458,6 +490,8 @@ int main(int argc, char *argv[])
       { "help",                        0,              0,      'h' },
       { "version",             0,              0,      'v' },
       { "usage",               0,              0,      'u' },
+      { "ipv4",                        0,              0,      '4' },
+      { "ipv6",                        0,              0,      '6' },
       { "listen",              OPTF_ARGREQ,    0,      'l' },
       { "peer",                        OPTF_ARGREQ,    0,      'p' },
       { "bind",                        OPTF_ARGREQ,    0,      'b' },
@@ -466,13 +500,15 @@ int main(int argc, char *argv[])
     };
     int i;
 
-    i = mdwopt(argc, argv, "hvul:p:b:c:", opt, 0, 0, 0);
+    i = mdwopt(argc, argv, "hvu46l:p:b:c:", opt, 0, 0, 0);
     if (i < 0)
       break;
     switch (i) {
       case 'h': help(stdout); exit(0);
       case 'v': version(stdout); exit(0);
       case 'u': usage(stdout); exit(0);
+      case '4': af = AF_INET; break;
+      case '6': af = AF_INET6; break;
       case 'l': bindsvc = optarg; break;
       case 'p': DA_PUSH(&peerhosts, optarg); break;
       case 'b': DA_PUSH(&bindhosts, optarg); break;
@@ -489,7 +525,7 @@ int main(int argc, char *argv[])
   if (bindsvc && connhost)
     die(1, "can't listen and connect");
 
-  aihint.ai_family = AF_INET;
+  aihint.ai_family = af;
   DA_CREATE(&cw.me); DA_CREATE(&cw.peer);
 
   n = DA_LEN(&bindhosts);
@@ -557,7 +593,7 @@ int main(int argc, char *argv[])
       die(1, "couldn't connect to TCP server: %s", strerror(errno));
   }
 
-  aihint.ai_family = AF_INET;
+  aihint.ai_family = af;
   aihint.ai_socktype = SOCK_DGRAM;
   aihint.ai_protocol = IPPROTO_UDP;
   aihint.ai_flags = AI_ADDRCONFIG | AI_PASSIVE;