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scm_to_sockaddr mishandles IPv6 addresses

From: Scott McPeak
Subject: scm_to_sockaddr mishandles IPv6 addresses
Date: Tue, 29 Sep 2009 20:16:50 -0700
User-agent: Thunderbird (X11/20081113)


In Guile-1.8.7, the function 'scm_to_sockaddr' mishandles IPv6
addresses.  Specifically, it passes the 'address' parameter (which is
a vector) to the 'scm_to_ipv6' function, which expects an integer.

I have a patch, at the end, that fixes the problem.

The patch also improves the error message produced by 'scm_to_ipv6'
when passed the wrong type of argument.  I realize it's somewhat
unconventional to use the C function name as the 'subr' in
'scm_wrong_type_arg_msg', but it to me it seems preferable to NULL; if
the message had included that name when it originally manifested in my
program, diagnosis would have taken less time.

Here is a demonstration of the problem.  I have a service listening on
port 8080 of the IPv6 loopback interface, "::1".  This code is running
on linux/x86_64.

Test program:

  $ cat testipv6.scm
  (define INADDR_LOOPBACK_IPV6 1)          ; "::1"
  (define sock (socket PF_INET6 SOCK_STREAM 0))
  (define addr (make-socket-address AF_INET6 INADDR_LOOPBACK_IPV6 8080))
  (display "about to connect\n")
  (connect sock addr)
  (display "connected!\n")
  (close-port sock)

Original behavior with Guile 1.8.7:

  $ guile testipv6.scm
  about to connect
  ERROR: Wrong type: #(10 1 8080 0 0)

After improving the scm_to_ipv6 error message:

  $ guile testipv6.scm
  about to connect
  ERROR: In procedure scm_to_ipv6:
  ERROR: Wrong type (expecting integer): #(10 1 8080 0 0)

After fixing the bug in scm_to_sockaddr:

  $ guile testipv6.scm
  about to connect


diff --git a/libguile/socket.c b/libguile/socket.c
index f34b6d4..b51e4f1 100644
--- a/libguile/socket.c
+++ b/libguile/socket.c
@@ -347,7 +347,7 @@ scm_to_ipv6 (scm_t_uint8 dst[16], SCM src)
       scm_remember_upto_here_1 (src);
-    scm_wrong_type_arg (NULL, 0, src);
+    scm_wrong_type_arg_msg ("scm_to_ipv6", 0, src, "integer");

@@ -1167,7 +1167,7 @@ scm_to_sockaddr (SCM address, size_t *address_size)
            struct sockaddr_in6 c_inet6;

-           scm_to_ipv6 (c_inet6.sin6_addr.s6_addr, address);
+ scm_to_ipv6 (c_inet6.sin6_addr.s6_addr, SCM_SIMPLE_VECTOR_REF (address, 1));
            c_inet6.sin6_port =
              htons (scm_to_ushort (SCM_SIMPLE_VECTOR_REF (address, 2)));
            c_inet6.sin6_flowinfo =

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