Improve sk_peer_info.

Previously, it returned a human-readable string suitable for log
files, which tried to say something useful about the remote end of a
socket. Now it returns a whole SocketPeerInfo structure, of which that
human-friendly log string is just one field, but also some of the same
information - remote IP address and port, in particular - is provided
in machine-readable form where it's available.

defs.h

@@ -44,6 +44,7 @@ typedef struct SockAddr SockAddr;
 
 typedef struct Socket Socket;
 typedef struct Plug Plug;
+typedef struct SocketPeerInfo SocketPeerInfo;
 
 typedef struct Backend Backend;
 typedef struct BackendVtable BackendVtable;

errsock.c

@@ -39,7 +39,7 @@ static const char *sk_error_socket_error(Socket *s)
     return es->error;
 }
 
-static char *sk_error_peer_info(Socket *s)
+static SocketPeerInfo *sk_error_peer_info(Socket *s)
 {
     return NULL;
 }

mainchan.c

@@ -88,7 +88,8 @@ mainchan *mainchan_new(
         const char *host = conf_get_str(mc->conf, CONF_ssh_nc_host);
         int port = conf_get_int(mc->conf, CONF_ssh_nc_port);
 
-        mc->sc = ssh_lportfwd_open(cl, host, port, "main channel", &mc->chan);
+        mc->sc = ssh_lportfwd_open(cl, host, port, "main channel",
+                                   NULL, &mc->chan);
         mc->type = MAINCHAN_DIRECT_TCPIP;
     } else {
         mc->sc = ssh_session_open(cl, &mc->chan);

misc.c

@@ -1416,3 +1416,12 @@ const char *nullseat_get_x_display(Seat *seat) { return NULL; }
 int nullseat_get_windowid(Seat *seat, long *id_out) { return FALSE; }
 int nullseat_get_window_pixel_size(
     Seat *seat, int *width, int *height) { return FALSE; }
+
+void sk_free_peer_info(SocketPeerInfo *pi)
+{
+    if (pi) {
+        sfree((char *)pi->addr_text);
+        sfree((char *)pi->log_text);
+        sfree(pi);
+    }
+}

network.h

@@ -35,7 +35,7 @@ struct SocketVtable {
     void (*set_frozen) (Socket *s, int is_frozen);
     /* ignored by tcp, but vital for ssl */
     const char *(*socket_error) (Socket *s);
-    char *(*peer_info) (Socket *s);
+    SocketPeerInfo *(*peer_info) (Socket *s);
 };
 
 typedef union { void *p; int i; } accept_ctx_t;
@@ -194,12 +194,52 @@ const char *sk_addr_error(SockAddr *addr);
 #define sk_set_frozen(s, is_frozen) (((s)->vt->set_frozen) (s, is_frozen))
 
 /*
- * Return a (dynamically allocated) string giving some information
+ * Return a structure giving some information about the other end of
- * about the other end of the socket, suitable for putting in log
+ * the socket. May be NULL, if nothing is available at all. If it is
- * files. May be NULL if nothing is available at all.
+ * not NULL, then it is dynamically allocated, and should be freed by
+ * a call to sk_free_peer_info(). See below for the definition.
  */
 #define sk_peer_info(s) (((s)->vt->peer_info) (s))
 
+/*
+ * The structure returned from sk_peer_info, and a function to free
+ * one (in misc.c).
+ */
+struct SocketPeerInfo {
+    int addressfamily;
+
+    /*
+     * Text form of the IPv4 or IPv6 address of the other end of the
+     * socket, if available, in the standard text representation.
+     */
+    const char *addr_text;
+
+    /*
+     * Binary form of the same address. Filled in if and only if
+     * addr_text is not NULL. You can tell which branch of the union
+     * is used by examining 'addressfamily'.
+     */
+    union {
+        unsigned char ipv6[16];
+        unsigned char ipv4[4];
+    } addr_bin;
+
+    /*
+     * Remote port number, or -1 if not available.
+     */
+    int port;
+
+    /*
+     * Free-form text suitable for putting in log messages. For IP
+     * sockets, repeats the address and port information from above.
+     * But it can be completely different, e.g. for Unix-domain
+     * sockets it gives information about the uid, gid and pid of the
+     * connecting process.
+     */
+    const char *log_text;
+};
+void sk_free_peer_info(SocketPeerInfo *pi);
+
 /*
  * Simple wrapper on getservbyname(), needed by ssh.c. Returns the
  * port number, in host byte order (suitable for printf and so on).

pageant.c

@@ -830,7 +830,7 @@ static int pageant_listen_accepting(Plug *plug,
         plug, struct pageant_listen_state, plug);
     struct pageant_conn_state *pc;
     const char *err;
-    char *peerinfo;
+    SocketPeerInfo *peerinfo;
 
     pc = snew(struct pageant_conn_state);
     pc->plug.vt = &pageant_connection_plugvt;
@@ -848,12 +848,13 @@ static int pageant_listen_accepting(Plug *plug,
     sk_set_frozen(pc->connsock, 0);
 
     peerinfo = sk_peer_info(pc->connsock);
-    if (peerinfo) {
+    if (peerinfo && peerinfo->log_text) {
         plog(pl->logctx, pl->logfn, "%p: new connection from %s",
-             pc, peerinfo);
+             pc, peerinfo->log_text);
     } else {
         plog(pl->logctx, pl->logfn, "%p: new connection", pc);
     }
+    sk_free_peer_info(peerinfo);
 
     return 0;
 }

portfwd.c

@@ -153,18 +153,18 @@ static SshChannel *wrap_lportfwd_open(
     ConnectionLayer *cl, const char *hostname, int port,
     Socket *s, Channel *chan)
 {
-    char *peerinfo, *description;
+    SocketPeerInfo *pi;
+    char *description;
     SshChannel *toret;
 
-    peerinfo = sk_peer_info(s);
+    pi = sk_peer_info(s);
-    if (peerinfo) {
+    if (pi && pi->log_text) {
-        description = dupprintf("forwarding from %s", peerinfo);
+        description = dupprintf("forwarding from %s", pi->log_text);
-        sfree(peerinfo);
     } else {
         description = dupstr("forwarding");
     }
-
+    toret = ssh_lportfwd_open(cl, hostname, port, description, pi, chan);
-    toret = ssh_lportfwd_open(cl, hostname, port, description, chan);
+    sk_free_peer_info(pi);
 
     sfree(description);
     return toret;

putty.h

@@ -483,7 +483,11 @@ enum {
      * host name has already been resolved or will be resolved at
      * the proxy end.
      */
-    ADDRTYPE_UNSPEC, ADDRTYPE_IPV4, ADDRTYPE_IPV6, ADDRTYPE_NAME
+    ADDRTYPE_UNSPEC,
+    ADDRTYPE_IPV4,
+    ADDRTYPE_IPV6,
+    ADDRTYPE_LOCAL,    /* e.g. Unix domain socket, or Windows named pipe */
+    ADDRTYPE_NAME      /* SockAddr storing an unresolved host name */
 };
 
 struct Backend {

ssh.h

@@ -216,7 +216,8 @@ struct ConnectionLayerVtable {
      * PortFwdManager */
     SshChannel *(*lportfwd_open)(
         ConnectionLayer *cl, const char *hostname, int port,
-        const char *org, Channel *chan);
+        const char *description, const SocketPeerInfo *peerinfo,
+        Channel *chan);
 
     /* Initiate opening of a 'session'-type channel */
     SshChannel *(*session_open)(ConnectionLayer *cl, Channel *chan);
@@ -297,8 +298,8 @@ struct ConnectionLayer {
 #define ssh_rportfwd_alloc(cl, sh, sp, dh, dp, af, ld, pfr, share) \
     ((cl)->vt->rportfwd_alloc(cl, sh, sp, dh, dp, af, ld, pfr, share))
 #define ssh_rportfwd_remove(cl, rpf) ((cl)->vt->rportfwd_remove(cl, rpf))
-#define ssh_lportfwd_open(cl, h, p, org, chan) \
+#define ssh_lportfwd_open(cl, h, p, desc, pi, chan) \
-    ((cl)->vt->lportfwd_open(cl, h, p, org, chan))
+    ((cl)->vt->lportfwd_open(cl, h, p, desc, pi, chan))
 #define ssh_session_open(cl, chan) \
     ((cl)->vt->session_open(cl, chan))
 #define ssh_add_x11_display(cl, auth, disp) \

ssh1connection.c

@@ -109,7 +109,7 @@ static void ssh1_rportfwd_remove(
     ConnectionLayer *cl, struct ssh_rportfwd *rpf);
 static SshChannel *ssh1_lportfwd_open(
     ConnectionLayer *cl, const char *hostname, int port,
-    const char *org, Channel *chan);
+    const char *description, const SocketPeerInfo *pi, Channel *chan);
 static SshChannel *ssh1_session_open(ConnectionLayer *cl, Channel *chan);
 static struct X11FakeAuth *ssh1_add_x11_display(
     ConnectionLayer *cl, int authtype, struct X11Display *disp);
@@ -1176,7 +1176,7 @@ static SshChannel *ssh1_session_open(ConnectionLayer *cl, Channel *chan)
 
 static SshChannel *ssh1_lportfwd_open(
     ConnectionLayer *cl, const char *hostname, int port,
-    const char *org, Channel *chan)
+    const char *description, const SocketPeerInfo *pi, Channel *chan)
 {
     struct ssh1_connection_state *s =
         container_of(cl, struct ssh1_connection_state, cl);
@@ -1189,7 +1189,8 @@ static SshChannel *ssh1_lportfwd_open(
     c->halfopen = TRUE;
     c->chan = chan;
 
-    ppl_logevent(("Opening connection to %s:%d for %s", hostname, port, org));
+    ppl_logevent(("Opening connection to %s:%d for %s",
+                  hostname, port, description));
 
     pktout = ssh_bpp_new_pktout(s->ppl.bpp, SSH1_MSG_PORT_OPEN);
     put_uint32(pktout, c->localid);

ssh2connection.c

@@ -104,7 +104,7 @@ static void ssh2_rportfwd_remove(
     ConnectionLayer *cl, struct ssh_rportfwd *rpf);
 static SshChannel *ssh2_lportfwd_open(
     ConnectionLayer *cl, const char *hostname, int port,
-    const char *org, Channel *chan);
+    const char *description, const SocketPeerInfo *pi, Channel *chan);
 static SshChannel *ssh2_session_open(ConnectionLayer *cl, Channel *chan);
 static struct X11FakeAuth *ssh2_add_x11_display(
     ConnectionLayer *cl, int authtype, struct X11Display *x11disp);
@@ -1678,7 +1678,7 @@ static void ssh2channel_hint_channel_is_simple(SshChannel *sc)
 
 static SshChannel *ssh2_lportfwd_open(
     ConnectionLayer *cl, const char *hostname, int port,
-    const char *org, Channel *chan)
+    const char *description, const SocketPeerInfo *pi, Channel *chan)
 {
     struct ssh2_connection_state *s =
         container_of(cl, struct ssh2_connection_state, cl);
@@ -1691,7 +1691,8 @@ static SshChannel *ssh2_lportfwd_open(
     c->halfopen = TRUE;
     c->chan = chan;
 
-    ppl_logevent(("Opening connection to %s:%d for %s", hostname, port, org));
+    ppl_logevent(("Opening connection to %s:%d for %s",
+                  hostname, port, description));
 
     pktout = ssh2_chanopen_init(c, "direct-tcpip");
     {

sshshare.c

@@ -1914,7 +1914,7 @@ static int share_listen_accepting(Plug *plug,
         plug, struct ssh_sharing_state, plug);
     struct ssh_sharing_connstate *cs;
     const char *err;
-    char *peerinfo;
+    SocketPeerInfo *peerinfo;
 
     /*
      * A new downstream has connected to us.
@@ -1959,9 +1959,9 @@ static int share_listen_accepting(Plug *plug,
 
     peerinfo = sk_peer_info(cs->sock);
     log_downstream(cs, "connected%s%s",
-                   peerinfo ? " from " : "", peerinfo ? peerinfo : "");
+                   (peerinfo && peerinfo->log_text ? " from " : ""),
-
+                   (peerinfo && peerinfo->log_text ? peerinfo->log_text : ""));
-    sfree(peerinfo);
+    sk_free_peer_info(peerinfo);
 
     return 0;
 }

unix/uxnet.c

@@ -503,7 +503,7 @@ static int sk_net_write(Socket *s, const void *data, int len);
 static int sk_net_write_oob(Socket *s, const void *data, int len);
 static void sk_net_write_eof(Socket *s);
 static void sk_net_set_frozen(Socket *s, int is_frozen);
-static char *sk_net_peer_info(Socket *s);
+static SocketPeerInfo *sk_net_peer_info(Socket *s);
 static const char *sk_net_socket_error(Socket *s);
 
 static struct SocketVtable NetSocket_sockvt = {
@@ -1480,7 +1480,7 @@ static void sk_net_set_frozen(Socket *sock, int is_frozen)
     uxsel_tell(s);
 }
 
-static char *sk_net_peer_info(Socket *sock)
+static SocketPeerInfo *sk_net_peer_info(Socket *sock)
 {
     NetSocket *s = container_of(sock, NetSocket, sock);
     union sockaddr_union addr;
@@ -1488,26 +1488,42 @@ static char *sk_net_peer_info(Socket *sock)
 #ifndef NO_IPV6
     char buf[INET6_ADDRSTRLEN];
 #endif
+    SocketPeerInfo *pi;
 
     if (getpeername(s->s, &addr.sa, &addrlen) < 0)
         return NULL;
+
+    pi = snew(SocketPeerInfo);
+    pi->addressfamily = ADDRTYPE_UNSPEC;
+    pi->addr_text = NULL;
+    pi->port = -1;
+    pi->log_text = NULL;
+
     if (addr.storage.ss_family == AF_INET) {
-        return dupprintf
+        pi->addressfamily = ADDRTYPE_IPV4;
-            ("%s:%d",
+        memcpy(pi->addr_bin.ipv4, &addr.sin.sin_addr, 4);
-             inet_ntoa(addr.sin.sin_addr),
+        pi->port = ntohs(addr.sin.sin_port);
-             (int)ntohs(addr.sin.sin_port));
+        pi->addr_text = dupstr(inet_ntoa(addr.sin.sin_addr));
+        pi->log_text = dupprintf("%s:%d", pi->addr_text, pi->port);
+
 #ifndef NO_IPV6
     } else if (addr.storage.ss_family == AF_INET6) {
-        return dupprintf
+        pi->addressfamily = ADDRTYPE_IPV6;
-            ("[%s]:%d",
+        memcpy(pi->addr_bin.ipv6, &addr.sin6.sin6_addr, 16);
-             inet_ntop(AF_INET6, &addr.sin6.sin6_addr, buf, sizeof(buf)),
+        pi->port = ntohs(addr.sin6.sin6_port);
-             (int)ntohs(addr.sin6.sin6_port));
+        pi->addr_text = dupstr(
+            inet_ntop(AF_INET6, &addr.sin6.sin6_addr, buf, sizeof(buf)));
+        pi->log_text = dupprintf("[%s]:%d", pi->addr_text, pi->port);
 #endif
+
     } else if (addr.storage.ss_family == AF_UNIX) {
+        pi->addressfamily = ADDRTYPE_LOCAL;
+
         /*
          * For Unix sockets, the source address is unlikely to be
-         * helpful. Instead, we try SO_PEERCRED and try to get the
+         * helpful, so we leave addr_txt NULL (and we certainly can't
-         * source pid.
+         * fill in port, obviously). Instead, we try SO_PEERCRED and
+         * try to get the source pid, and put that in the log text.
          */
         int pid, uid, gid;
         if (so_peercred(s->s, &pid, &uid, &gid)) {
@@ -1516,14 +1532,16 @@ static char *sk_net_peer_info(Socket *sock)
             sprintf(gidbuf, "%d", gid);
             struct passwd *pw = getpwuid(uid);
             struct group *gr = getgrgid(gid);
-            return dupprintf("pid %d (%s:%s)", pid,
+            pi->log_text = dupprintf("pid %d (%s:%s)", pid,
                                      pw ? pw->pw_name : uidbuf,
                                      gr ? gr->gr_name : gidbuf);
         }
-        return NULL;
     } else {
+        sfree(pi);
         return NULL;
     }
+
+    return pi;
 }
 
 static void uxsel_tell(NetSocket *s)

windows/winhsock.c

@@ -270,7 +270,7 @@ static const char *sk_handle_socket_error(Socket *s)
     return hs->error;
 }
 
-static char *sk_handle_peer_info(Socket *s)
+static SocketPeerInfo *sk_handle_peer_info(Socket *s)
 {
     HandleSocket *hs = container_of(s, HandleSocket, sock);
     ULONG pid;
@@ -299,8 +299,14 @@ static char *sk_handle_peer_info(Socket *s)
      * to log what we can find out about the client end.
      */
     if (p_GetNamedPipeClientProcessId &&
-        p_GetNamedPipeClientProcessId(hs->send_H, &pid))
+        p_GetNamedPipeClientProcessId(hs->send_H, &pid)) {
-        return dupprintf("process id %lu", (unsigned long)pid);
+        SocketPeerInfo *pi = snew(SocketPeerInfo);
+        pi->addressfamily = ADDRTYPE_LOCAL;
+        pi->addr_text = NULL;
+        pi->port = -1;
+        pi->log_text = dupprintf("process id %lu", (unsigned long)pid);
+        return pi;
+    }
 
     return NULL;
 }

windows/winnet.c

@@ -904,7 +904,7 @@ static int sk_net_write_oob(Socket *s, const void *data, int len);
 static void sk_net_write_eof(Socket *s);
 static void sk_net_set_frozen(Socket *s, int is_frozen);
 static const char *sk_net_socket_error(Socket *s);
-static char *sk_net_peer_info(Socket *s);
+static SocketPeerInfo *sk_net_peer_info(Socket *s);
 
 extern char *do_select(SOCKET skt, int startup);
 
@@ -1763,7 +1763,7 @@ static const char *sk_net_socket_error(Socket *sock)
     return s->error;
 }
 
-static char *sk_net_peer_info(Socket *sock)
+static SocketPeerInfo *sk_net_peer_info(Socket *sock)
 {
     NetSocket *s = container_of(sock, NetSocket, sock);
 #ifdef NO_IPV6
@@ -1773,26 +1773,43 @@ static char *sk_net_peer_info(Socket *sock)
     char buf[INET6_ADDRSTRLEN];
 #endif
     int addrlen = sizeof(addr);
+    SocketPeerInfo *pi;
 
     if (p_getpeername(s->s, (struct sockaddr *)&addr, &addrlen) < 0)
         return NULL;
 
+    pi = snew(SocketPeerInfo);
+    pi->addressfamily = ADDRTYPE_UNSPEC;
+    pi->addr_text = NULL;
+    pi->port = -1;
+    pi->log_text = NULL;
+
     if (((struct sockaddr *)&addr)->sa_family == AF_INET) {
-        return dupprintf
+        pi->addressfamily = ADDRTYPE_IPV4;
-            ("%s:%d",
+        memcpy(pi->addr_bin.ipv4, &((struct sockaddr_in *)&addr)->sin_addr, 4);
-             p_inet_ntoa(((struct sockaddr_in *)&addr)->sin_addr),
+        pi->port = p_ntohs(((struct sockaddr_in *)&addr)->sin_port);
-             (int)p_ntohs(((struct sockaddr_in *)&addr)->sin_port));
+        pi->addr_text = dupstr(
+            p_inet_ntoa(((struct sockaddr_in *)&addr)->sin_addr));
+        pi->log_text = dupprintf("%s:%d", pi->addr_text, pi->port);
+
 #ifndef NO_IPV6
     } else if (((struct sockaddr *)&addr)->sa_family == AF_INET6) {
-        return dupprintf
+        pi->addressfamily = ADDRTYPE_IPV6;
-            ("[%s]:%d",
+        memcpy(pi->addr_bin.ipv6,
+               &((struct sockaddr_in6 *)&addr)->sin6_addr, 16);
+        pi->port = p_ntohs(((struct sockaddr_in6 *)&addr)->sin6_port);
+        pi->addr_text = dupstr(
             p_inet_ntop(AF_INET6, &((struct sockaddr_in6 *)&addr)->sin6_addr,
-                         buf, sizeof(buf)),
+                        buf, sizeof(buf)));
-             (int)p_ntohs(((struct sockaddr_in6 *)&addr)->sin6_port));
+        pi->log_text = dupprintf("[%s]:%d", pi->addr_text, pi->port);
+
 #endif
     } else {
+        sfree(pi);
         return NULL;
     }
+
+    return pi;
 }
 
 static void sk_net_set_frozen(Socket *sock, int is_frozen)

windows/winnps.c

@@ -68,7 +68,7 @@ static const char *sk_namedpipeserver_socket_error(Socket *s)
     return ps->error;
 }
 
-static char *sk_namedpipeserver_peer_info(Socket *s)
+static SocketPeerInfo *sk_namedpipeserver_peer_info(Socket *s)
 {
     return NULL;
 }