[ruby-dev:28683] Re: `Socket#unpack_sockaddr_un': sockaddr_un size differs - 15 required; 110 given (TypeError)

In article <[e-mail]>,
  Tanaka Akira <[e-mail]> writes:

> ふと気がついたのですが、Socket.unpack_sockaddr_un に
> UNIXServer#getsockname で得たアドレスを渡すとエラーになりま
> す。
>
> % ./ruby -v -rsocket -e '
> File.unlink("/tmp/tmpsock") rescue nil
> s = UNIXServer.new("/tmp/tmpsock")
> p s.getsockname
> p Socket.unpack_sockaddr_un(s.getsockname)'
> ruby 1.9.0 (2006-06-01) [i686-linux]
> "\001\000/tmp/tmpsock\000"
> -e:5:in `Socket#unpack_sockaddr_un': sockaddr_un size differs - 15 required; 110 given (TypeError)
>         from -e:5
>
> getsockname で得たものをうまく扱えないのは変じゃないでしょう
> か。

この他、無名の UNIX ソケットの addr, peeraddr, path が変だとか、

% ruby -v -rsocket -e '
s1, s2 = UNIXSocket.pair         
p s1.addr                         
p s1.peeraddr
p s1.path
'
ruby 1.9.0 (2006-06-02) [i686-linux]
["AF_UNIX", "\224\272\332\267\2408\356\267\241j\341\267HZ\364\267"]
["AF_UNIX", "\374 \332\267\034)\332\267\200v\024\010\034)\332\267\001"]
"\034)\332\267\200v\024\010\034)\332\267\001"

UNIXSocket#path が接続先のパスを返すとか、

% ruby -v -rsocket -e '
UNIXServer.open("/tmp/s") {|serv|
  p UNIXSocket.open("/tmp/s").path
}'
ruby 1.9.0 (2006-06-02) [i686-linux]
"/tmp/s"

UNIXServer.open で作ったはずのところにソケットがないとか、

% ruby -v -rsocket -e '                                                                                         
path = "/tmp/" + "s" * 120
UNIXServer.open(path) {|serv|
  p File.stat(path)
}'
ruby 1.9.0 (2006-06-02) [i686-linux]
-e:4:in `File#stat': No such file or directory - /tmp/ssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss (Errno::ENOENT)
        from -e:4
        from -e:3

といった問題を直すにはこうですかね。

Index: ext/socket/socket.c
===================================================================
RCS file: /src/ruby/ext/socket/socket.c,v
retrieving revision 1.167
diff -u -p -r1.167 socket.c
--- ext/socket/socket.c	2 Jun 2006 12:06:09 -0000	1.167
+++ ext/socket/socket.c	3 Jun 2006 04:38:24 -0000
@@ -543,7 +543,7 @@ bsock_do_not_reverse_lookup_set(sock, st
 
 static VALUE ipaddr _((struct sockaddr*, int));
 #ifdef HAVE_SYS_UN_H
-static VALUE unixaddr _((struct sockaddr_un*));
+static VALUE unixaddr _((struct sockaddr_un*, socklen_t));
 #endif
 
 enum sock_recv_type {
@@ -620,10 +620,7 @@ s_recvfrom(sock, argc, argv, from)
 
 #ifdef HAVE_SYS_UN_H
       case RECV_UNIX:
-        if (alen) /* connection-oriented socket may not return a from result */
-            return rb_assoc_new(str, unixaddr((struct sockaddr_un*)buf));
-        else
-            return rb_assoc_new(str, Qnil);
+        return rb_assoc_new(str, unixaddr((struct sockaddr_un*)buf, alen));
 #endif
       case RECV_SOCKET:
 	return rb_assoc_new(str, rb_str_new(buf, alen));
@@ -685,8 +682,7 @@ s_recvfrom_nonblock(int argc, VALUE *arg
 
 #ifdef HAVE_SYS_UN_H
       case RECV_UNIX:
-        if (alen) /* connection-oriented socket may not return a from result */
-            addr = unixaddr((struct sockaddr_un*)buf);
+        addr = unixaddr((struct sockaddr_un*)buf, alen);
         break;
 #endif
 
@@ -1607,8 +1603,11 @@ init_unixsock(sock, path, server)
 
     MEMZERO(&sockaddr, struct sockaddr_un, 1);
     sockaddr.sun_family = AF_UNIX;
-    strncpy(sockaddr.sun_path, RSTRING(path)->ptr, sizeof(sockaddr.sun_path)-1);
-    sockaddr.sun_path[sizeof(sockaddr.sun_path)-1] = '\0';
+    if (sizeof(sockaddr.sun_path) <= RSTRING(path)->len) {
+        rb_raise(rb_eArgError, "too long unix socket path (max: %dbytes)",
+            (int)sizeof(sockaddr.sun_path)-1);
+    }
+    strcpy(sockaddr.sun_path, StringValueCStr(path));
 
     if (server) {
         status = bind(fd, (struct sockaddr*)&sockaddr, sizeof(sockaddr));
@@ -1634,7 +1633,9 @@ init_unixsock(sock, path, server)
 
     init_sock(sock, fd);
     GetOpenFile(sock, fptr);
-    fptr->path = strdup(RSTRING(path)->ptr);
+    if (server) {
+        fptr->path = strdup(RSTRING(path)->ptr);
+    }
 
     return sock;
 }
@@ -1866,6 +1867,15 @@ unix_init(sock, path)
     return init_unixsock(sock, path, 0);
 }
 
+static char *
+unixpath(struct sockaddr_un *sockaddr, socklen_t len)
+{
+    if (sockaddr->sun_path < (char*)sockaddr + len)
+        return sockaddr->sun_path;
+    else
+        return "";
+}
+
 static VALUE
 unix_path(sock)
     VALUE sock;
@@ -1878,7 +1888,7 @@ unix_path(sock)
 	socklen_t len = sizeof(addr);
 	if (getsockname(fptr->fd, (struct sockaddr*)&addr, &len) < 0)
 	    rb_sys_fail(0);
-	fptr->path = strdup(addr.sun_path);
+	fptr->path = strdup(unixpath(&addr, len));
     }
     return rb_str_new2(fptr->path);
 }
@@ -2201,11 +2211,12 @@ unix_sysaccept(sock)
 
 #ifdef HAVE_SYS_UN_H
 static VALUE
-unixaddr(sockaddr)
+unixaddr(sockaddr, len)
     struct sockaddr_un *sockaddr;
+    socklen_t len;
 {
     return rb_assoc_new(rb_str_new2("AF_UNIX"),
-			rb_str_new2(sockaddr->sun_path));
+                        rb_str_new2(unixpath(sockaddr, len)));
 }
 #endif
 
@@ -2221,9 +2232,7 @@ unix_addr(sock)
 
     if (getsockname(fptr->fd, (struct sockaddr*)&addr, &len) < 0)
 	rb_sys_fail("getsockname(2)");
-    if (len == 0)
-        addr.sun_path[0] = '\0';
-    return unixaddr(&addr);
+    return unixaddr(&addr, len);
 }
 
 static VALUE
@@ -2238,9 +2247,7 @@ unix_peeraddr(sock)
 
     if (getpeername(fptr->fd, (struct sockaddr*)&addr, &len) < 0)
 	rb_sys_fail("getsockname(2)");
-    if (len == 0)
-        addr.sun_path[0] = '\0';
-    return unixaddr(&addr);
+    return unixaddr(&addr, len);
 }
 #endif
 
@@ -3516,11 +3523,17 @@ sock_s_pack_sockaddr_un(self, path)
     VALUE self, path;
 {
     struct sockaddr_un sockaddr;
+    char *sun_path;
     VALUE addr;
 
     MEMZERO(&sockaddr, struct sockaddr_un, 1);
     sockaddr.sun_family = AF_UNIX;
-    strncpy(sockaddr.sun_path, StringValuePtr(path), sizeof(sockaddr.sun_path)-1);
+    sun_path = StringValueCStr(path);
+    if (sizeof(sockaddr.sun_path) <= strlen(sun_path)) {
+        rb_raise(rb_eArgError, "too long unix socket path (max: %dbytes)",
+            (int)sizeof(sockaddr.sun_path)-1);
+    }
+    strncpy(sockaddr.sun_path, sun_path, sizeof(sockaddr.sun_path)-1);
     addr = rb_str_new((char*)&sockaddr, sizeof(sockaddr));
     OBJ_INFECT(addr, path);
 
@@ -3532,15 +3545,21 @@ sock_s_unpack_sockaddr_un(self, addr)
     VALUE self, addr;
 {
     struct sockaddr_un * sockaddr;
+    char *sun_path;
     VALUE path;
 
     sockaddr = (struct sockaddr_un*)StringValuePtr(addr);
-    if (RSTRING(addr)->len != sizeof(struct sockaddr_un)) {
-	rb_raise(rb_eTypeError, "sockaddr_un size differs - %ld required; %d given",
+    if (sizeof(struct sockaddr_un) < RSTRING(addr)->len) {
+	rb_raise(rb_eTypeError, "too long sockaddr_un - %ld longer than %d",
 		 RSTRING(addr)->len, sizeof(struct sockaddr_un));
     }
-    /* xxx: should I check against sun_path size? */
-    path = rb_str_new2(sockaddr->sun_path);
+    sun_path = unixpath(sockaddr, RSTRING(addr)->len);
+    if (sizeof(struct sockaddr_un) == RSTRING(addr)->len &&
+        sun_path == sockaddr->sun_path &&
+        sun_path + strlen(sun_path) == RSTRING(addr)->ptr + RSTRING(addr)->len) {
+        rb_raise(rb_eArgError, "sockaddr_un.sun_path not NUL terminated");
+    }
+    path = rb_str_new2(sun_path);
     OBJ_INFECT(path, addr);
     return path;
 }
-- 
[田中 哲][たなか あきら][Tanaka Akira]