1 files changed, 202 insertions, 101 deletions

diff --git a/channels.c b/channels.c
index 92448da77..530c0d460 100644
--- a/channels.c
+++ b/channels.c
@@ -1,3 +1,4 @@
+/* $OpenBSD: channels.c,v 1.268 2007/01/03 03:01:40 stevesk Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -39,22 +40,41 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: channels.c,v 1.232 2006/01/30 12:22:22 reyk Exp $");
 
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/un.h>
+#include <sys/socket.h>
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h>
+#endif
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <errno.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+#include <stdarg.h>
+
+#include "xmalloc.h"
 #include "ssh.h"
 #include "ssh1.h"
 #include "ssh2.h"
 #include "packet.h"
-#include "xmalloc.h"
 #include "log.h"
 #include "misc.h"
+#include "buffer.h"
 #include "channels.h"
 #include "compat.h"
 #include "canohost.h"
 #include "key.h"
 #include "authfd.h"
 #include "pathnames.h"
-#include "bufaux.h"
 
 /* -- channel core */
 
@@ -91,11 +111,18 @@ typedef struct {
         u_short listen_port;            /* Remote side should listen port number. */
 } ForwardPermission;
 
-/* List of all permitted host/port pairs to connect. */
+/* List of all permitted host/port pairs to connect by the user. */
 static ForwardPermission permitted_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
 
-/* Number of permitted host/port pairs in the array. */
+/* List of all permitted host/port pairs to connect by the admin. */
+static ForwardPermission permitted_adm_opens[SSH_MAX_FORWARDS_PER_DIRECTION];
+
+/* Number of permitted host/port pairs in the array permitted by the user. */
 static int num_permitted_opens = 0;
+
+/* Number of permitted host/port pair in the array permitted by the admin. */
+static int num_adm_permitted_opens = 0;
+
 /*
  * If this is true, all opens are permitted.  This is the case on the server
  * on which we have to trust the client anyway, and the user could do
@@ -123,7 +150,7 @@ static u_int x11_saved_data_len = 0;
  * Fake X11 authentication data.  This is what the server will be sending us;
  * we should replace any occurrences of this by the real data.
  */
-static char *x11_fake_data = NULL;
+static u_char *x11_fake_data = NULL;
 static u_int x11_fake_data_len;
 
 
@@ -168,7 +195,7 @@ channel_lookup(int id)
         if ((c = channel_by_id(id)) == NULL)
                 return (NULL);
 
-        switch(c->type) {
+        switch (c->type) {
         case SSH_CHANNEL_X11_OPEN:
         case SSH_CHANNEL_LARVAL:
         case SSH_CHANNEL_CONNECTING:
@@ -178,7 +205,6 @@ channel_lookup(int id)
         case SSH_CHANNEL_INPUT_DRAINING:
         case SSH_CHANNEL_OUTPUT_DRAINING:
                 return (c);
-                break;
         }
         logit("Non-public channel %d, type %d.", id, c->type);
         return (NULL);
@@ -188,7 +214,6 @@ channel_lookup(int id)
  * Register filedescriptors for a channel, used when allocating a channel or
  * when the channel consumer/producer is ready, e.g. shell exec'd
  */
-
 static void
 channel_register_fds(Channel *c, int rfd, int wfd, int efd,
     int extusage, int nonblock)
@@ -235,7 +260,6 @@ channel_register_fds(Channel *c, int rfd, int wfd, int efd,
  * Allocate a new channel object and set its type and socket. This will cause
  * remote_name to be freed.
  */
-
 Channel *
 channel_new(char *ctype, int type, int rfd, int wfd, int efd,
     u_int window, u_int maxpack, int extusage, char *remote_name, int nonblock)
@@ -247,7 +271,7 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
         /* Do initial allocation if this is the first call. */
         if (channels_alloc == 0) {
                 channels_alloc = 10;
-                channels = xmalloc(channels_alloc * sizeof(Channel *));
+                channels = xcalloc(channels_alloc, sizeof(Channel *));
                 for (i = 0; i < channels_alloc; i++)
                         channels[i] = NULL;
         }
@@ -264,16 +288,15 @@ channel_new(char *ctype, int type, int rfd, int wfd, int efd,
                 if (channels_alloc > 10000)
                         fatal("channel_new: internal error: channels_alloc %d "
                             "too big.", channels_alloc);
-                channels = xrealloc(channels,
-                    (channels_alloc + 10) * sizeof(Channel *));
+                channels = xrealloc(channels, channels_alloc + 10,
+                    sizeof(Channel *));
                 channels_alloc += 10;
                 debug2("channel: expanding %d", channels_alloc);
                 for (i = found; i < channels_alloc; i++)
                         channels[i] = NULL;
         }
         /* Initialize and return new channel. */
-        c = channels[found] = xmalloc(sizeof(Channel));
-        memset(c, 0, sizeof(Channel));
+        c = channels[found] = xcalloc(1, sizeof(Channel));
         buffer_init(&c->input);
         buffer_init(&c->output);
         buffer_init(&c->extended);
@@ -337,7 +360,6 @@ channel_close_fd(int *fdp)
 }
 
 /* Close all channel fd/socket. */
-
 static void
 channel_close_fds(Channel *c)
 {
@@ -352,7 +374,6 @@ channel_close_fds(Channel *c)
 }
 
 /* Free the channel and close its fd/socket. */
-
 void
 channel_free(Channel *c)
 {
@@ -399,7 +420,6 @@ channel_free_all(void)
  * Closes the sockets/fds of all channels.  This is used to close extra file
  * descriptors after a fork.
  */
-
 void
 channel_close_all(void)
 {
@@ -413,7 +433,6 @@ channel_close_all(void)
 /*
  * Stop listening to channels.
  */
-
 void
 channel_stop_listening(void)
 {
@@ -440,7 +459,6 @@ channel_stop_listening(void)
  * Returns true if no channel has too much buffered data, and false if one or
  * more channel is overfull.
  */
-
 int
 channel_not_very_much_buffered_data(void)
 {
@@ -470,7 +488,6 @@ channel_not_very_much_buffered_data(void)
 }
 
 /* Returns true if any channel is still open. */
-
 int
 channel_still_open(void)
 {
@@ -513,7 +530,6 @@ channel_still_open(void)
 }
 
 /* Returns the id of an open channel suitable for keepaliving */
-
 int
 channel_find_open(void)
 {
@@ -558,7 +574,6 @@ channel_find_open(void)
  * suitable for sending to the client.  The message contains crlf pairs for
  * newlines.
  */
-
 char *
 channel_open_message(void)
 {
@@ -643,6 +658,7 @@ channel_request_start(int id, char *service, int wantconfirm)
         packet_put_cstring(service);
         packet_put_char(wantconfirm);
 }
+
 void
 channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
 {
@@ -655,6 +671,7 @@ channel_register_confirm(int id, channel_callback_fn *fn, void *ctx)
         c->confirm = fn;
         c->confirm_ctx = ctx;
 }
+
 void
 channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
 {
@@ -667,6 +684,7 @@ channel_register_cleanup(int id, channel_callback_fn *fn, int do_close)
         c->detach_user = fn;
         c->detach_close = do_close;
 }
+
 void
 channel_cancel_cleanup(int id)
 {
@@ -679,6 +697,7 @@ channel_cancel_cleanup(int id)
         c->detach_user = NULL;
         c->detach_close = 0;
 }
+
 void
 channel_register_filter(int id, channel_infilter_fn *ifn,
     channel_outfilter_fn *ofn)
@@ -718,25 +737,27 @@ channel_set_fds(int id, int rfd, int wfd, int efd,
  * 'channel_post*': perform any appropriate operations for channels which
  * have events pending.
  */
-typedef void chan_fn(Channel *c, fd_set * readset, fd_set * writeset);
+typedef void chan_fn(Channel *c, fd_set *readset, fd_set *writeset);
 chan_fn *channel_pre[SSH_CHANNEL_MAX_TYPE];
 chan_fn *channel_post[SSH_CHANNEL_MAX_TYPE];
 
+/* ARGSUSED */
 static void
-channel_pre_listener(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_listener(Channel *c, fd_set *readset, fd_set *writeset)
 {
         FD_SET(c->sock, readset);
 }
 
+/* ARGSUSED */
 static void
-channel_pre_connecting(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_connecting(Channel *c, fd_set *readset, fd_set *writeset)
 {
         debug3("channel %d: waiting for connection", c->self);
         FD_SET(c->sock, writeset);
 }
 
 static void
-channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_open_13(Channel *c, fd_set *readset, fd_set *writeset)
 {
         if (buffer_len(&c->input) < packet_get_maxsize())
                 FD_SET(c->sock, readset);
@@ -745,16 +766,14 @@ channel_pre_open_13(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 static void
-channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_open(Channel *c, fd_set *readset, fd_set *writeset)
 {
         u_int limit = compat20 ? c->remote_window : packet_get_maxsize();
 
-        /* check buffer limits */
-        limit = MIN(limit, (BUFFER_MAX_LEN - BUFFER_MAX_CHUNK - CHAN_RBUF));
-
         if (c->istate == CHAN_INPUT_OPEN &&
             limit > 0 &&
-            buffer_len(&c->input) < limit)
+            buffer_len(&c->input) < limit &&
+            buffer_check_alloc(&c->input, CHAN_RBUF))
                 FD_SET(c->rfd, readset);
         if (c->ostate == CHAN_OUTPUT_OPEN ||
             c->ostate == CHAN_OUTPUT_WAIT_DRAIN) {
@@ -784,8 +803,9 @@ channel_pre_open(Channel *c, fd_set * readset, fd_set * writeset)
                 FD_SET(c->ctl_fd, readset);
 }
 
+/* ARGSUSED */
 static void
-channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_input_draining(Channel *c, fd_set *readset, fd_set *writeset)
 {
         if (buffer_len(&c->input) == 0) {
                 packet_start(SSH_MSG_CHANNEL_CLOSE);
@@ -796,8 +816,9 @@ channel_pre_input_draining(Channel *c, fd_set * readset, fd_set * writeset)
         }
 }
 
+/* ARGSUSED */
 static void
-channel_pre_output_draining(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_output_draining(Channel *c, fd_set *readset, fd_set *writeset)
 {
         if (buffer_len(&c->output) == 0)
                 chan_mark_dead(c);
@@ -873,7 +894,7 @@ x11_open_helper(Buffer *b)
 }
 
 static void
-channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_x11_open_13(Channel *c, fd_set *readset, fd_set *writeset)
 {
         int ret = x11_open_helper(&c->output);
 
@@ -899,7 +920,7 @@ channel_pre_x11_open_13(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 static void
-channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_x11_open(Channel *c, fd_set *readset, fd_set *writeset)
 {
         int ret = x11_open_helper(&c->output);
 
@@ -925,8 +946,9 @@ channel_pre_x11_open(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 /* try to decode a socks4 header */
+/* ARGSUSED */
 static int
-channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
+channel_decode_socks4(Channel *c, fd_set *readset, fd_set *writeset)
 {
         char *p, *host;
         u_int len, have, i, found;
@@ -990,7 +1012,7 @@ channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
         s4_rsp.command = 90;                    /* cd: req granted */
         s4_rsp.dest_port = 0;                   /* ignored */
         s4_rsp.dest_addr.s_addr = INADDR_ANY;   /* ignored */
-        buffer_append(&c->output, (char *)&s4_rsp, sizeof(s4_rsp));
+        buffer_append(&c->output, &s4_rsp, sizeof(s4_rsp));
         return 1;
 }
 
@@ -1003,8 +1025,9 @@ channel_decode_socks4(Channel *c, fd_set * readset, fd_set * writeset)
 #define SSH_SOCKS5_CONNECT      0x01
 #define SSH_SOCKS5_SUCCESS      0x00
 
+/* ARGSUSED */
 static int
-channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
+channel_decode_socks5(Channel *c, fd_set *readset, fd_set *writeset)
 {
         struct {
                 u_int8_t version;
@@ -1014,7 +1037,7 @@ channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
         } s5_req, s5_rsp;
         u_int16_t dest_port;
         u_char *p, dest_addr[255+1];
-        u_int have, i, found, nmethods, addrlen, af;
+        u_int have, need, i, found, nmethods, addrlen, af;
 
         debug2("channel %d: decode socks5", c->self);
         p = buffer_ptr(&c->input);
@@ -1029,8 +1052,8 @@ channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
                 if (have < nmethods + 2)
                         return 0;
                 /* look for method: "NO AUTHENTICATION REQUIRED" */
-                for (found = 0, i = 2 ; i < nmethods + 2; i++) {
-                        if (p[i] == SSH_SOCKS5_NOAUTH ) {
+                for (found = 0, i = 2; i < nmethods + 2; i++) {
+                        if (p[i] == SSH_SOCKS5_NOAUTH) {
                                 found = 1;
                                 break;
                         }
@@ -1051,7 +1074,7 @@ channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
         debug2("channel %d: socks5 post auth", c->self);
         if (have < sizeof(s5_req)+1)
                 return 0;                       /* need more */
-        memcpy((char *)&s5_req, p, sizeof(s5_req));
+        memcpy(&s5_req, p, sizeof(s5_req));
         if (s5_req.version != 0x05 ||
             s5_req.command != SSH_SOCKS5_CONNECT ||
             s5_req.reserved != 0x00) {
@@ -1075,7 +1098,10 @@ channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
                 debug2("channel %d: bad socks5 atyp %d", c->self, s5_req.atyp);
                 return -1;
         }
-        if (have < 4 + addrlen + 2)
+        need = sizeof(s5_req) + addrlen + 2;
+        if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
+                need++;
+        if (have < need)
                 return 0;
         buffer_consume(&c->input, sizeof(s5_req));
         if (s5_req.atyp == SSH_SOCKS5_DOMAIN)
@@ -1099,15 +1125,15 @@ channel_decode_socks5(Channel *c, fd_set * readset, fd_set * writeset)
         ((struct in_addr *)&dest_addr)->s_addr = INADDR_ANY;
         dest_port = 0;                          /* ignored */
 
-        buffer_append(&c->output, (char *)&s5_rsp, sizeof(s5_rsp));
-        buffer_append(&c->output, (char *)&dest_addr, sizeof(struct in_addr));
-        buffer_append(&c->output, (char *)&dest_port, sizeof(dest_port));
+        buffer_append(&c->output, &s5_rsp, sizeof(s5_rsp));
+        buffer_append(&c->output, &dest_addr, sizeof(struct in_addr));
+        buffer_append(&c->output, &dest_port, sizeof(dest_port));
         return 1;
 }
 
 /* dynamic port forwarding */
 static void
-channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
+channel_pre_dynamic(Channel *c, fd_set *readset, fd_set *writeset)
 {
         u_char *p;
         u_int have;
@@ -1150,8 +1176,9 @@ channel_pre_dynamic(Channel *c, fd_set * readset, fd_set * writeset)
 }
 
 /* This is our fake X11 server socket. */
+/* ARGSUSED */
 static void
-channel_post_x11_listener(Channel *c, fd_set * readset, fd_set * writeset)
+channel_post_x11_listener(Channel *c, fd_set *readset, fd_set *writeset)
 {
         Channel *nc;
         struct sockaddr addr;
@@ -1275,8 +1302,9 @@ channel_set_reuseaddr(int fd)
 /*
  * This socket is listening for connections to a forwarded TCP/IP port.
  */
+/* ARGSUSED */
 static void
-channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
+channel_post_port_listener(Channel *c, fd_set *readset, fd_set *writeset)
 {
         Channel *nc;
         struct sockaddr addr;
@@ -1332,8 +1360,9 @@ channel_post_port_listener(Channel *c, fd_set * readset, fd_set * writeset)
  * This is the authentication agent socket listening for connections from
  * clients.
  */
+/* ARGSUSED */
 static void
-channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
+channel_post_auth_listener(Channel *c, fd_set *readset, fd_set *writeset)
 {
         Channel *nc;
         int newsock;
@@ -1365,8 +1394,9 @@ channel_post_auth_listener(Channel *c, fd_set * readset, fd_set * writeset)
         }
 }
 
+/* ARGSUSED */
 static void
-channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
+channel_post_connecting(Channel *c, fd_set *readset, fd_set *writeset)
 {
         int err = 0;
         socklen_t sz = sizeof(err);
@@ -1411,18 +1441,26 @@ channel_post_connecting(Channel *c, fd_set * readset, fd_set * writeset)
         }
 }
 
+/* ARGSUSED */
 static int
-channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
+channel_handle_rfd(Channel *c, fd_set *readset, fd_set *writeset)
 {
         char buf[CHAN_RBUF];
         int len;
 
         if (c->rfd != -1 &&
-            FD_ISSET(c->rfd, readset)) {
+            (c->detach_close || FD_ISSET(c->rfd, readset))) {
+                errno = 0;
                 len = read(c->rfd, buf, sizeof(buf));
-                if (len < 0 && (errno == EINTR || errno == EAGAIN))
+                if (len < 0 && (errno == EINTR ||
+                    (errno == EAGAIN && !(c->isatty && c->detach_close))))
                         return 1;
+#ifndef PTY_ZEROREAD
                 if (len <= 0) {
+#else
+                if ((!c->isatty && len <= 0) ||
+                    (c->isatty && (len < 0 || (len == 0 && errno != 0)))) {
+#endif
                         debug2("channel %d: read<=0 rfd %d len %d",
                             c->self, c->rfd, len);
                         if (c->type != SSH_CHANNEL_OPEN) {
@@ -1451,8 +1489,10 @@ channel_handle_rfd(Channel *c, fd_set * readset, fd_set * writeset)
         }
         return 1;
 }
+
+/* ARGSUSED */
 static int
-channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
+channel_handle_wfd(Channel *c, fd_set *readset, fd_set *writeset)
 {
         struct termios tio;
         u_char *data = NULL, *buf;
@@ -1538,8 +1578,9 @@ channel_handle_wfd(Channel *c, fd_set * readset, fd_set * writeset)
         }
         return 1;
 }
+
 static int
-channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
+channel_handle_efd(Channel *c, fd_set *readset, fd_set *writeset)
 {
         char buf[CHAN_RBUF];
         int len;
@@ -1564,11 +1605,12 @@ channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
                                 c->local_consumed += len;
                         }
                 } else if (c->extended_usage == CHAN_EXTENDED_READ &&
-                    FD_ISSET(c->efd, readset)) {
+                    (c->detach_close || FD_ISSET(c->efd, readset))) {
                         len = read(c->efd, buf, sizeof(buf));
                         debug2("channel %d: read %d from efd %d",
                             c->self, len, c->efd);
-                        if (len < 0 && (errno == EINTR || errno == EAGAIN))
+                        if (len < 0 && (errno == EINTR ||
+                            (errno == EAGAIN && !c->detach_close)))
                                 return 1;
                         if (len <= 0) {
                                 debug2("channel %d: closing read-efd %d",
@@ -1581,8 +1623,10 @@ channel_handle_efd(Channel *c, fd_set * readset, fd_set * writeset)
         }
         return 1;
 }
+
+/* ARGSUSED */
 static int
-channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
+channel_handle_ctl(Channel *c, fd_set *readset, fd_set *writeset)
 {
         char buf[16];
         int len;
@@ -1608,6 +1652,7 @@ channel_handle_ctl(Channel *c, fd_set * readset, fd_set * writeset)
         }
         return 1;
 }
+
 static int
 channel_check_window(Channel *c)
 {
@@ -1629,7 +1674,7 @@ channel_check_window(Channel *c)
 }
 
 static void
-channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
+channel_post_open(Channel *c, fd_set *readset, fd_set *writeset)
 {
         if (c->delayed)
                 return;
@@ -1642,8 +1687,9 @@ channel_post_open(Channel *c, fd_set * readset, fd_set * writeset)
         channel_check_window(c);
 }
 
+/* ARGSUSED */
 static void
-channel_post_output_drain_13(Channel *c, fd_set * readset, fd_set * writeset)
+channel_post_output_drain_13(Channel *c, fd_set *readset, fd_set *writeset)
 {
         int len;
 
@@ -1760,7 +1806,7 @@ channel_garbage_collect(Channel *c)
 }
 
 static void
-channel_handler(chan_fn *ftab[], fd_set * readset, fd_set * writeset)
+channel_handler(chan_fn *ftab[], fd_set *readset, fd_set *writeset)
 {
         static int did_init = 0;
         u_int i;
@@ -1788,15 +1834,20 @@ void
 channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
     u_int *nallocp, int rekeying)
 {
-        u_int n, sz;
+        u_int n, sz, nfdset;
 
         n = MAX(*maxfdp, channel_max_fd);
 
-        sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
+        nfdset = howmany(n+1, NFDBITS);
+        /* Explicitly test here, because xrealloc isn't always called */
+        if (nfdset && SIZE_T_MAX / nfdset < sizeof(fd_mask))
+                fatal("channel_prepare_select: max_fd (%d) is too large", n);
+        sz = nfdset * sizeof(fd_mask);
+
         /* perhaps check sz < nalloc/2 and shrink? */
         if (*readsetp == NULL || sz > *nallocp) {
-                *readsetp = xrealloc(*readsetp, sz);
-                *writesetp = xrealloc(*writesetp, sz);
+                *readsetp = xrealloc(*readsetp, nfdset, sizeof(fd_mask));
+                *writesetp = xrealloc(*writesetp, nfdset, sizeof(fd_mask));
                 *nallocp = sz;
         }
         *maxfdp = n;
@@ -1812,14 +1863,13 @@ channel_prepare_select(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
  * events pending.
  */
 void
-channel_after_select(fd_set * readset, fd_set * writeset)
+channel_after_select(fd_set *readset, fd_set *writeset)
 {
         channel_handler(channel_post, readset, writeset);
 }
 
 
 /* If there is data to send to the connection, enqueue some of it now. */
-
 void
 channel_output_poll(void)
 {
@@ -1940,6 +1990,7 @@ channel_output_poll(void)
 
 /* -- protocol input */
 
+/* ARGSUSED */
 void
 channel_input_data(int type, u_int32_t seq, void *ctxt)
 {
@@ -1999,6 +2050,7 @@ channel_input_data(int type, u_int32_t seq, void *ctxt)
         xfree(data);
 }
 
+/* ARGSUSED */
 void
 channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
 {
@@ -2045,6 +2097,7 @@ channel_input_extended_data(int type, u_int32_t seq, void *ctxt)
         xfree(data);
 }
 
+/* ARGSUSED */
 void
 channel_input_ieof(int type, u_int32_t seq, void *ctxt)
 {
@@ -2068,6 +2121,7 @@ channel_input_ieof(int type, u_int32_t seq, void *ctxt)
 
 }
 
+/* ARGSUSED */
 void
 channel_input_close(int type, u_int32_t seq, void *ctxt)
 {
@@ -2106,6 +2160,7 @@ channel_input_close(int type, u_int32_t seq, void *ctxt)
 }
 
 /* proto version 1.5 overloads CLOSE_CONFIRMATION with OCLOSE */
+/* ARGSUSED */
 void
 channel_input_oclose(int type, u_int32_t seq, void *ctxt)
 {
@@ -2118,6 +2173,7 @@ channel_input_oclose(int type, u_int32_t seq, void *ctxt)
         chan_rcvd_oclose(c);
 }
 
+/* ARGSUSED */
 void
 channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
 {
@@ -2134,6 +2190,7 @@ channel_input_close_confirmation(int type, u_int32_t seq, void *ctxt)
         channel_free(c);
 }
 
+/* ARGSUSED */
 void
 channel_input_open_confirmation(int type, u_int32_t seq, void *ctxt)
 {
@@ -2181,6 +2238,7 @@ reason2txt(int reason)
         return "unknown reason";
 }
 
+/* ARGSUSED */
 void
 channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
 {
@@ -2212,6 +2270,7 @@ channel_input_open_failure(int type, u_int32_t seq, void *ctxt)
         channel_free(c);
 }
 
+/* ARGSUSED */
 void
 channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
 {
@@ -2236,6 +2295,7 @@ channel_input_window_adjust(int type, u_int32_t seq, void *ctxt)
         c->remote_window += adjust;
 }
 
+/* ARGSUSED */
 void
 channel_input_port_open(int type, u_int32_t seq, void *ctxt)
 {
@@ -2454,7 +2514,7 @@ channel_setup_remote_fwd_listener(const char *listen_address,
  * the secure channel to host:port from local side.
  */
 
-void
+int
 channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
     const char *host_to_connect, u_short port_to_connect)
 {
@@ -2467,11 +2527,18 @@ channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
         /* Send the forward request to the remote side. */
         if (compat20) {
                 const char *address_to_bind;
-                if (listen_host == NULL)
-                        address_to_bind = "localhost";
-                else if (*listen_host == '\0' || strcmp(listen_host, "*") == 0)
-                        address_to_bind = "";
-                else
+                if (listen_host == NULL) {
+                        if (datafellows & SSH_BUG_RFWD_ADDR)
+                                address_to_bind = "127.0.0.1";
+                        else
+                                address_to_bind = "localhost";
+                } else if (*listen_host == '\0' ||
+                           strcmp(listen_host, "*") == 0) {
+                        if (datafellows & SSH_BUG_RFWD_ADDR)
+                                address_to_bind = "0.0.0.0";
+                        else
+                                address_to_bind = "";
+                } else
                         address_to_bind = listen_host;
 
                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
@@ -2498,7 +2565,6 @@ channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
                         success = 1;
                         break;
                 case SSH_SMSG_FAILURE:
-                        logit("Warning: Server denied remote port forwarding.");
                         break;
                 default:
                         /* Unknown packet */
@@ -2512,6 +2578,7 @@ channel_request_remote_forwarding(const char *listen_host, u_short listen_port,
                 permitted_opens[num_permitted_opens].listen_port = listen_port;
                 num_permitted_opens++;
         }
+        return (success ? 0 : -1);
 }
 
 /*
@@ -2551,13 +2618,13 @@ channel_request_rforward_cancel(const char *host, u_short port)
 /*
  * This is called after receiving CHANNEL_FORWARDING_REQUEST.  This initates
  * listening for the port, and sends back a success reply (or disconnect
- * message if there was an error).  This never returns if there was an error.
+ * message if there was an error).
  */
-
-void
+int
 channel_input_port_forward_request(int is_root, int gateway_ports)
 {
         u_short port, host_port;
+        int success = 0;
         char *hostname;
 
         /* Get arguments from the packet. */
@@ -2579,11 +2646,13 @@ channel_input_port_forward_request(int is_root, int gateway_ports)
 #endif
 
         /* Initiate forwarding */
-        channel_setup_local_fwd_listener(NULL, port, hostname,
+        success = channel_setup_local_fwd_listener(NULL, port, hostname,
             host_port, gateway_ports);
 
         /* Free the argument string. */
         xfree(hostname);
+
+        return (success ? 0 : -1);
 }
 
 /*
@@ -2602,7 +2671,7 @@ void
 channel_add_permitted_opens(char *host, int port)
 {
         if (num_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
-                fatal("channel_request_remote_forwarding: too many forwards");
+                fatal("channel_add_permitted_opens: too many forwards");
         debug("allow port forwarding to host %s port %d", host, port);
 
         permitted_opens[num_permitted_opens].host_to_connect = xstrdup(host);
@@ -2612,6 +2681,19 @@ channel_add_permitted_opens(char *host, int port)
         all_opens_permitted = 0;
 }
 
+int
+channel_add_adm_permitted_opens(char *host, int port)
+{
+        if (num_adm_permitted_opens >= SSH_MAX_FORWARDS_PER_DIRECTION)
+                fatal("channel_add_adm_permitted_opens: too many forwards");
+        debug("config allows port forwarding to host %s port %d", host, port);
+
+        permitted_adm_opens[num_adm_permitted_opens].host_to_connect
+             = xstrdup(host);
+        permitted_adm_opens[num_adm_permitted_opens].port_to_connect = port;
+        return ++num_adm_permitted_opens;
+}
+
 void
 channel_clear_permitted_opens(void)
 {
@@ -2621,9 +2703,18 @@ channel_clear_permitted_opens(void)
                 if (permitted_opens[i].host_to_connect != NULL)
                         xfree(permitted_opens[i].host_to_connect);
         num_permitted_opens = 0;
-
 }
 
+void
+channel_clear_adm_permitted_opens(void)
+{
+        int i;
+
+        for (i = 0; i < num_adm_permitted_opens; i++)
+                if (permitted_adm_opens[i].host_to_connect != NULL)
+                        xfree(permitted_adm_opens[i].host_to_connect);
+        num_adm_permitted_opens = 0;
+}
 
 /* return socket to remote host, port */
 static int
@@ -2701,7 +2792,7 @@ channel_connect_by_listen_address(u_short listen_port)
 int
 channel_connect_to(const char *host, u_short port)
 {
-        int i, permit;
+        int i, permit, permit_adm = 1;
 
         permit = all_opens_permitted;
         if (!permit) {
@@ -2710,9 +2801,19 @@ channel_connect_to(const char *host, u_short port)
                             permitted_opens[i].port_to_connect == port &&
                             strcmp(permitted_opens[i].host_to_connect, host) == 0)
                                 permit = 1;
+        }
 
+        if (num_adm_permitted_opens > 0) {
+                permit_adm = 0;
+                for (i = 0; i < num_adm_permitted_opens; i++)
+                        if (permitted_adm_opens[i].host_to_connect != NULL &&
+                            permitted_adm_opens[i].port_to_connect == port &&
+                            strcmp(permitted_adm_opens[i].host_to_connect, host)
+                            == 0)
+                                permit_adm = 1;
         }
-        if (!permit) {
+
+        if (!permit || !permit_adm) {
                 logit("Received request to connect to host %.100s port %d, "
                     "but the request was denied.", host, port);
                 return -1;
@@ -2733,10 +2834,10 @@ channel_send_window_changes(void)
                 if (ioctl(channels[i]->rfd, TIOCGWINSZ, &ws) < 0)
                         continue;
                 channel_request_start(i, "window-change", 0);
-                packet_put_int(ws.ws_col);
-                packet_put_int(ws.ws_row);
-                packet_put_int(ws.ws_xpixel);
-                packet_put_int(ws.ws_ypixel);
+                packet_put_int((u_int)ws.ws_col);
+                packet_put_int((u_int)ws.ws_row);
+                packet_put_int((u_int)ws.ws_xpixel);
+                packet_put_int((u_int)ws.ws_ypixel);
                 packet_send();
         }
 }
@@ -2848,7 +2949,7 @@ x11_create_display_inet(int x11_display_offset, int x11_use_localhost,
         }
 
         /* Allocate a channel for each socket. */
-        *chanids = xmalloc(sizeof(**chanids) * (num_socks + 1));
+        *chanids = xcalloc(num_socks + 1, sizeof(**chanids));
         for (n = 0; n < num_socks; n++) {
                 sock = socks[n];
                 nc = channel_new("x11 listener",
@@ -2877,7 +2978,7 @@ connect_local_xsocket(u_int dnr)
         memset(&addr, 0, sizeof(addr));
         addr.sun_family = AF_UNIX;
         snprintf(addr.sun_path, sizeof addr.sun_path, _PATH_UNIX_X, dnr);
-        if (connect(sock, (struct sockaddr *) & addr, sizeof(addr)) == 0)
+        if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == 0)
                 return sock;
         close(sock);
         error("connect %.100s: %.100s", addr.sun_path, strerror(errno));
@@ -2887,12 +2988,12 @@ connect_local_xsocket(u_int dnr)
 int
 x11_connect_display(void)
 {
-        int display_number, sock = 0;
+        u_int display_number;
         const char *display;
         char buf[1024], *cp;
         struct addrinfo hints, *ai, *aitop;
         char strport[NI_MAXSERV];
-        int gaierr;
+        int gaierr, sock = 0;
 
         /* Try to open a socket for the local X server. */
         display = getenv("DISPLAY");
@@ -2912,7 +3013,7 @@ x11_connect_display(void)
         if (strncmp(display, "unix:", 5) == 0 ||
             display[0] == ':') {
                 /* Connect to the unix domain socket. */
-                if (sscanf(strrchr(display, ':') + 1, "%d", &display_number) != 1) {
+                if (sscanf(strrchr(display, ':') + 1, "%u", &display_number) != 1) {
                         error("Could not parse display number from DISPLAY: %.100s",
                             display);
                         return -1;
@@ -2937,7 +3038,7 @@ x11_connect_display(void)
         }
         *cp = 0;
         /* buf now contains the host name.  But first we parse the display number. */
-        if (sscanf(cp + 1, "%d", &display_number) != 1) {
+        if (sscanf(cp + 1, "%u", &display_number) != 1) {
                 error("Could not parse display number from DISPLAY: %.100s",
                     display);
                 return -1;
@@ -2947,7 +3048,7 @@ x11_connect_display(void)
         memset(&hints, 0, sizeof(hints));
         hints.ai_family = IPv4or6;
         hints.ai_socktype = SOCK_STREAM;
-        snprintf(strport, sizeof strport, "%d", 6000 + display_number);
+        snprintf(strport, sizeof strport, "%u", 6000 + display_number);
         if ((gaierr = getaddrinfo(buf, strport, &hints, &aitop)) != 0) {
                 error("%.100s: unknown host. (%s)", buf, gai_strerror(gaierr));
                 return -1;
@@ -2961,7 +3062,7 @@ x11_connect_display(void)
                 }
                 /* Connect it to the display. */
                 if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0) {
-                        debug2("connect %.100s port %d: %.100s", buf,
+                        debug2("connect %.100s port %u: %.100s", buf,
                             6000 + display_number, strerror(errno));
                         close(sock);
                         continue;
@@ -2971,7 +3072,7 @@ x11_connect_display(void)
         }
         freeaddrinfo(aitop);
         if (!ai) {
-                error("connect %.100s port %d: %.100s", buf, 6000 + display_number,
+                error("connect %.100s port %u: %.100s", buf, 6000 + display_number,
                     strerror(errno));
                 return -1;
         }
@@ -2985,6 +3086,7 @@ x11_connect_display(void)
  * with either SSH_MSG_OPEN_CONFIRMATION or SSH_MSG_OPEN_FAILURE.
  */
 
+/* ARGSUSED */
 void
 x11_input_open(int type, u_int32_t seq, void *ctxt)
 {
@@ -3028,6 +3130,7 @@ x11_input_open(int type, u_int32_t seq, void *ctxt)
 }
 
 /* dummy protocol handler that denies SSH-1 requests (agent/x11) */
+/* ARGSUSED */
 void
 deny_input_open(int type, u_int32_t seq, void *ctxt)
 {
@@ -3074,13 +3177,11 @@ x11_request_forwarding_with_spoofing(int client_session_id, const char *disp,
                 return;
         }
 
-        cp = disp;
-        if (disp)
-                cp = strchr(disp, ':');
+        cp = strchr(disp, ':');
         if (cp)
                 cp = strchr(cp, '.');
         if (cp)
-                screen_number = atoi(cp + 1);
+                screen_number = (u_int)strtonum(cp + 1, 0, 400, NULL);
         else
                 screen_number = 0;