X-Git-Url: https://git.distorted.org.uk/~mdw/tripe/blobdiff_plain/1afc65b695d97ffb79a023e72bf2d255f167d7f7..HEAD:/pkstream/pkstream.c

diff --git a/pkstream/pkstream.c b/pkstream/pkstream.c
index 88ff381a..8b2a058c 100644
--- a/pkstream/pkstream.c
+++ b/pkstream/pkstream.c
@@ -45,6 +45,7 @@
 
 #include <mLib/alloc.h>
 #include <mLib/bits.h>
+#include <mLib/darray.h>
 #include <mLib/dstr.h>
 #include <mLib/fdflags.h>
 #include <mLib/mdwopt.h>
@@ -57,6 +58,15 @@
 
 /*----- Data structures ---------------------------------------------------*/
 
+typedef union addr {
+  struct sockaddr sa;
+  struct sockaddr_in sin;
+  struct sockaddr_in6 sin6;
+} addr;
+
+DA_DECL(addr_v, addr);
+DA_DECL(str_v, const char *);
+
 typedef struct pk {
   struct pk *next;			/* Next packet in the chain */
   octet *p, *o;				/* Buffer start and current posn */
@@ -73,9 +83,10 @@ typedef struct pkstream {
 } pkstream;
 
 typedef struct connwait {
-  sel_file a;				/* Selector */
-  struct sockaddr_in me;		/* Who I'm meant to be */
-  struct in_addr peer;			/* Who my peer is */
+  unsigned f;				/* Various flags */
+#define cwf_port 1u			/*   Port is defined => listen */
+  sel_file *sfv;			/* Selectors */
+  addr_v me, peer;		       /* Who I'm meant to be; who peer is */
 } connwait;
 
 /*----- Static variables --------------------------------------------------*/
@@ -93,6 +104,111 @@ static int nonblockify(int fd)
 static int cloexec(int fd)
   { return (fdflags(fd, 0, 0, FD_CLOEXEC, FD_CLOEXEC)); }
 
+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();
+  }
+}
+
+static int knownafp(int af)
+{
+  switch (af) {
+    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);
+}
+
+static const char *addrstr(const addr *a)
+{
+  static char buf[128];
+  socklen_t n = sizeof(buf);
+
+  if (getnameinfo(&a->sa, addrsz(a), buf, n, 0, 0, NI_NUMERICHOST))
+    return ("<addrstr failed>");
+  return (buf);
+}
+
+static int addreq(const addr *a, const addr *b)
+{
+  if (a->sa.sa_family != b->sa.sa_family) return (0);
+  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();
+  }
+}
+
+static void initaddr(addr *a, int af)
+{
+  a->sa.sa_family = af;
+  switch (af) {
+    case AF_INET:
+      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();
+  }
+}
+
+#define caf_addr 1u
+#define caf_port 2u
+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) {
+    case AF_INET:
+      sin = (const struct sockaddr_in *)sa;
+      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();
+  }
+}
+
 static void dolisten(void);
 
 static void doclose(pkstream *p)
@@ -109,7 +225,7 @@ static void doclose(pkstream *p)
     xfree(pk);
   }
   xfree(p);
-  if (cw.me.sin_port) dolisten();
+  if (cw.f&cwf_port) dolisten();
   else exit(0);
 }
 
@@ -217,75 +333,109 @@ static void dofwd(int fd_in, int fd_out)
 static void doaccept(int fd_s, unsigned mode, void *p)
 {
   int fd;
-  struct sockaddr_in sin;
-  socklen_t sz = sizeof(sin);
+  addr a;
+  socklen_t sz = sizeof(a);
+  size_t i, n;
 
-  if ((fd = accept(fd_s, (struct sockaddr *)&sin, &sz)) < 0) {
+  if ((fd = accept(fd_s, &a.sa, &sz)) < 0) {
     if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) return;
     moan("couldn't accept incoming connection: %s", strerror(errno));
     return;
   }
-  if (cw.peer.s_addr != INADDR_ANY &&
-      cw.peer.s_addr != sin.sin_addr.s_addr) {
-    moan("rejecting connection from %s", inet_ntoa(sin.sin_addr));
-    close(fd); return;
-  }
+  n = DA_LEN(&cw.peer);
+  if (!n) goto match;
+  for (i = 0; i < n; i++) if (addreq(&a, &DA(&cw.peer)[i])) goto match;
+  moan("rejecting connection from %s", addrstr(&a));
+  close(fd); return;
+match:
   if (nonblockify(fd) || cloexec(fd)) {
     moan("couldn't accept incoming connection: %s", strerror(errno));
     close(fd); return;
   }
   dofwd(fd, fd);
-  close(fd_s);
-  sel_rmfile(&cw.a);
+  n = DA_LEN(&cw.me);
+  for (i = 0; i < n; i++) { close(cw.sfv[i].fd); sel_rmfile(&cw.sfv[i]); }
 }
 
-static void dolisten(void)
+static void dolisten1(const addr *a, sel_file *sf)
 {
   int fd;
   int opt = 1;
 
-  if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
+  if ((fd = socket(a->sa.sa_family, SOCK_STREAM, IPPROTO_TCP)) < 0 ||
       setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) ||
-      bind(fd, (struct sockaddr *)&cw.me, sizeof(cw.me)) ||
+      initsock(fd, a->sa.sa_family) ||
+      bind(fd, &a->sa, addrsz(a)) ||
       listen(fd, 1) || nonblockify(fd) || cloexec(fd))
     die(1, "couldn't set up listening socket: %s", strerror(errno));
-  sel_initfile(&sel, &cw.a, fd, SEL_READ, doaccept, 0);
-  sel_addfile(&cw.a);
+  sel_initfile(&sel, sf, fd, SEL_READ, doaccept, 0);
+  sel_addfile(sf);
 }
 
-static void parseaddr(const char *pp, struct in_addr *a, unsigned short *pt)
+static void dolisten(void)
 {
-  char *p = xstrdup(pp);
-  char *q = 0;
-  struct hostent *h;
-  struct servent *s;
-  char *qq;
-  unsigned long n;
-
-  if (!pt);
-  else if (a) q = p;
-  else {
-    strtok(p, ":");
-    q = strtok(0, "");
-    if (!q) die(1, "missing port number in address `%s'", p);
+  size_t i, n;
+
+  n = DA_LEN(&cw.me);
+  for (i = 0; i < n; i++)
+    dolisten1(&DA(&cw.me)[i], &cw.sfv[i]);
+}
+
+static void pushaddrs(addr_v *av, const struct addrinfo *ailist)
+{
+  const struct addrinfo *ai;
+  size_t i, n;
+
+  for (ai = ailist, n = 0; ai; ai = ai->ai_next)
+    if (knownafp(ai->ai_family)) n++;
+  DA_ENSURE(av, n);
+  for (i = DA_LEN(av), ai = ailist; ai; ai = ai->ai_next) {
+    if (!knownafp(ai->ai_family)) continue;
+    initaddr(&DA(av)[i], ai->ai_family);
+    copyaddr(&DA(av)[i++], ai->ai_addr, caf_addr | caf_port);
   }
+  DA_EXTEND(av, n);
+}
 
-  if (a) {
-    if ((h = gethostbyname(p)) == 0) die(1, "unknown host `%s'", p);
-    memcpy(a, h->h_addr, sizeof(*a));
+#define paf_parse 1u
+static void parseaddr(const struct addrinfo *aihint,
+		      const char *host, const char *svc, unsigned f,
+		      struct addrinfo **ai_out)
+{
+  char *alloc = 0, *sep;
+  int err;
+
+  if (f&paf_parse) {
+    alloc = xstrdup(host);
+    if (alloc[0] != '[') {
+      if ((sep = strchr(alloc, ':')) == 0)
+	die(1, "missing port number in address `%s'", host);
+      host = alloc; *sep = 0; svc = sep + 1;
+    } else {
+      if ((sep = strchr(alloc, ']')) == 0 || sep[1] != ':')
+	die(1, "bad syntax in address `%s:'", host);
+      host = alloc + 1; *sep = 0; svc = sep + 2;
+    }
   }
 
-  if (pt) {
-    if ((n = strtoul(q, &qq, 0)) > 0 && !*qq && n <= 0xffff) *pt = htons(n);
-    else if ((s = getservbyname(q, "tcp")) != 0) *pt = s->s_port;
-    else die(1, "bad port number `%s'", q);
+  err = getaddrinfo(host, svc, aihint, ai_out);
+  if (err) {
+    if (host && svc) {
+      die(1, "failed to resolve hostname `%s', service `%s': %s",
+	  host, svc, gai_strerror(err));
+    } else if (host)
+      die(1, "failed to resolve hostname `%s': %s", host, gai_strerror(err));
+    else
+      die(1, "failed to resolve service `%s': %s", svc, gai_strerror(err));
   }
+
+  xfree(alloc);
 }
 
 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");
 }
 
@@ -304,6 +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\
@@ -317,30 +469,29 @@ stdout; though it can use TCP sockets instead.\n\
 int main(int argc, char *argv[])
 {
   unsigned f = 0;
-  unsigned short pt;
-  struct sockaddr_in connaddr, bindaddr;
-  struct sockaddr_in udp_me, udp_peer;
-  int fd;
+  str_v bindhosts = DA_INIT, peerhosts = DA_INIT;
+  const char *bindsvc = 0;
+  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;
 
 #define f_bogus 1u
 
+  cw.f = 0;
+
   ego(argv[0]);
-  bindaddr.sin_family = AF_INET;
-  bindaddr.sin_addr.s_addr = INADDR_ANY;
-  bindaddr.sin_port = 0;
-  connaddr.sin_family = AF_INET;
-  connaddr.sin_addr.s_addr = INADDR_ANY;
-  cw.me.sin_family = AF_INET;
-  cw.me.sin_addr.s_addr = INADDR_ANY;
-  cw.me.sin_port = 0;
-  cw.peer.s_addr = INADDR_ANY;
   sel_init(&sel);
   for (;;) {
     static struct option opt[] = {
       { "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' },
@@ -349,55 +500,126 @@ 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 'l': parseaddr(optarg, 0, &pt); cw.me.sin_port = pt; break;
-      case 'p': parseaddr(optarg, &cw.peer, 0); break;
-      case 'b':
-	parseaddr(optarg, &bindaddr.sin_addr, 0);
-	cw.me.sin_addr = bindaddr.sin_addr;
-	break;
-      case 'c':
-	parseaddr(optarg, &connaddr.sin_addr, 0);
-	connaddr.sin_port = pt;
-	break;
+      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;
+      case 'c': connhost = optarg; break;
       default: f |= f_bogus; break;
     }
   }
   if (optind + 2 != argc || (f&f_bogus)) { usage(stderr); exit(1); }
 
-  udp_me.sin_family = udp_peer.sin_family = AF_INET;
-  parseaddr(argv[optind], &udp_me.sin_addr, &pt);
-  udp_me.sin_port = pt;
-  parseaddr(argv[optind + 1], &udp_peer.sin_addr, &pt);
-  udp_peer.sin_port = pt;
+  if (DA_LEN(&bindhosts) && !bindsvc && !connhost)
+    die(1, "bind addr only makes sense when listening or connecting");
+  if (DA_LEN(&peerhosts) && !bindsvc)
+    die(1, "peer addr only makes sense when listening");
+  if (bindsvc && connhost)
+    die(1, "can't listen and connect");
+
+  aihint.ai_family = af;
+  DA_CREATE(&cw.me); DA_CREATE(&cw.peer);
+
+  n = DA_LEN(&bindhosts);
+  if (n || bindsvc) {
+    aihint.ai_socktype = SOCK_STREAM;
+    aihint.ai_protocol = IPPROTO_TCP;
+    aihint.ai_flags = AI_ADDRCONFIG | AI_PASSIVE;
+    if (!n) {
+      parseaddr(&aihint, 0, bindsvc, 0, &ailist);
+      pushaddrs(&cw.me, ailist);
+      freeaddrinfo(ailist);
+    } else if (!bindsvc) {
+      if (n != 1) die(1, "can only bind to one address as client");
+      parseaddr(&aihint, DA(&bindhosts)[0], 0, 0, &ailist);
+      for (ai = ailist; ai && !knownafp(ai->ai_family); ai = ai->ai_next);
+      if (!ai)
+	die(1, "no usable addresses returned for `%s'", DA(&bindhosts)[0]);
+      initaddr(&bindaddr, ai->ai_family);
+      copyaddr(&bindaddr, ai->ai_addr, caf_addr);
+      aihint.ai_family = ai->ai_family;
+      freeaddrinfo(ailist);
+    } else for (i = 0; i < n; i++) {
+      parseaddr(&aihint, DA(&bindhosts)[i], bindsvc, 0, &ailist);
+      pushaddrs(&cw.me, ailist);
+      freeaddrinfo(ailist);
+    }
+    if (bindsvc) {
+      cw.f |= cwf_port;
+      n = DA_LEN(&cw.me);
+      cw.sfv = xmalloc(n*sizeof(*cw.sfv));
+    }
+  }
 
-  if ((fd_udp = socket(PF_INET, SOCK_DGRAM, 0)) < 0 ||
-      bind(fd_udp, (struct sockaddr *)&udp_me, sizeof(udp_me)) ||
-      connect(fd_udp, (struct sockaddr *)&udp_peer, sizeof(udp_peer)) ||
-      setsockopt(fd_udp, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
-      setsockopt(fd_udp, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)) ||
-      nonblockify(fd_udp) || cloexec(fd_udp))
-    die(1, "couldn't set up UDP socket: %s", strerror(errno));
+  n = DA_LEN(&peerhosts);
+  if (n) {
+    aihint.ai_socktype = SOCK_STREAM;
+    aihint.ai_protocol = IPPROTO_TCP;
+    aihint.ai_flags = AI_ADDRCONFIG;
+    for (i = 0; i < n; i++) {
+      parseaddr(&aihint, DA(&peerhosts)[i], 0, 0, &ailist);
+      pushaddrs(&cw.peer, ailist);
+      freeaddrinfo(ailist);
+    }
+    if (!DA_LEN(&cw.peer)) die(1, "no usable peer addresses");
+  }
 
-  if (cw.me.sin_port != 0)
-    dolisten();
-  else if (connaddr.sin_addr.s_addr == INADDR_ANY)
-    dofwd(STDIN_FILENO, STDOUT_FILENO);
-  else {
-    if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
-	bind(fd, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) ||
-	connect(fd, (struct sockaddr *)&connaddr, sizeof(connaddr)) ||
-	nonblockify(fd) || cloexec(fd))
+  if (connhost) {
+    aihint.ai_socktype = SOCK_STREAM;
+    aihint.ai_protocol = IPPROTO_TCP;
+    aihint.ai_flags = AI_ADDRCONFIG;
+    parseaddr(&aihint, connhost, 0, paf_parse, &ailist);
+
+    for (ai = ailist; ai; ai = ai->ai_next) {
+      if ((fd = socket(ai->ai_family, SOCK_STREAM, IPPROTO_TCP)) >= 0 &&
+	  !initsock(fd, ai->ai_family) &&
+	  (!DA_LEN(&bindhosts) ||
+	   !bind(fd, &bindaddr.sa, addrsz(&bindaddr))) &&
+	  !connect(fd, ai->ai_addr, ai->ai_addrlen))
+	goto conn_tcp;
+      if (fd >= 0) close(fd);
+    }
+    die(1, "couldn't connect to TCP server: %s", strerror(errno));
+  conn_tcp:
+    if (nonblockify(fd) || cloexec(fd))
       die(1, "couldn't connect to TCP server: %s", strerror(errno));
-    dofwd(fd, fd);
   }
 
+  aihint.ai_family = af;
+  aihint.ai_socktype = SOCK_DGRAM;
+  aihint.ai_protocol = IPPROTO_UDP;
+  aihint.ai_flags = AI_ADDRCONFIG | AI_PASSIVE;
+  parseaddr(&aihint, argv[optind], 0, paf_parse, &ailist);
+  for (ai = ailist; ai && !knownafp(ai->ai_family); ai = ai->ai_next);
+  if (!ai) die(1, "no usable addresses returned for `%s'", argv[optind]);
+  if ((fd_udp = socket(ai->ai_family, SOCK_DGRAM, IPPROTO_UDP)) < 0 ||
+      initsock(fd_udp, ai->ai_family) ||
+      nonblockify(fd_udp) || cloexec(fd_udp) ||
+      setsockopt(fd_udp, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
+      setsockopt(fd_udp, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)) ||
+      bind(fd_udp, ai->ai_addr, ai->ai_addrlen))
+    die(1, "couldn't set up UDP socket: %s", strerror(errno));
+  freeaddrinfo(ailist);
+  aihint.ai_family = ai->ai_family;
+  aihint.ai_flags = AI_ADDRCONFIG;
+  parseaddr(&aihint, argv[optind + 1], 0, paf_parse, &ailist);
+  for (ai = ailist; ai; ai = ai->ai_next)
+    if (!connect(fd_udp, ai->ai_addr, ai->ai_addrlen)) goto conn_udp;
+  die(1, "couldn't set up UDP socket: %s", strerror(errno));
+conn_udp:
+
+  if (bindsvc) dolisten();
+  else if (connhost) dofwd(fd, fd);
+  else dofwd(STDIN_FILENO, STDOUT_FILENO);
+
   for (;;) {
     if (sel_select(&sel) && errno != EINTR)
       die(1, "select failed: %s", strerror(errno));