1 files changed, 291 insertions, 0 deletions

diff --git a/openbsd-compat/port-net.c b/openbsd-compat/port-net.c
new file mode 100644
index 000000000..0e75c911d
--- /dev/null
+++ b/openbsd-compat/port-net.c
@@ -0,0 +1,291 @@
+/*
+ * Copyright (c) 2005 Reyk Floeter <reyk@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include "includes.h"
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netinet/ip.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "openbsd-compat/sys-queue.h"
+#include "log.h"
+#include "misc.h"
+#include "sshbuf.h"
+#include "channels.h"
+#include "ssherr.h"
+
+/*
+ * This is the portable version of the SSH tunnel forwarding, it
+ * uses some preprocessor definitions for various platform-specific
+ * settings.
+ *
+ * SSH_TUN_LINUX        Use the (newer) Linux tun/tap device
+ * SSH_TUN_FREEBSD      Use the FreeBSD tun/tap device
+ * SSH_TUN_COMPAT_AF    Translate the OpenBSD address family
+ * SSH_TUN_PREPEND_AF   Prepend/remove the address family
+ */
+
+/*
+ * System-specific tunnel open function
+ */
+
+#if defined(SSH_TUN_LINUX)
+#include <linux/if.h>
+#include <linux/if_tun.h>
+
+int
+sys_tun_open(int tun, int mode, char **ifname)
+{
+        struct ifreq ifr;
+        int fd = -1;
+        const char *name = NULL;
+
+        if (ifname != NULL)
+                *ifname = NULL;
+
+        if ((fd = open("/dev/net/tun", O_RDWR)) == -1) {
+                debug("%s: failed to open tunnel control interface: %s",
+                    __func__, strerror(errno));
+                return (-1);
+        }
+
+        bzero(&ifr, sizeof(ifr));
+
+        if (mode == SSH_TUNMODE_ETHERNET) {
+                ifr.ifr_flags = IFF_TAP;
+                name = "tap%d";
+        } else {
+                ifr.ifr_flags = IFF_TUN;
+                name = "tun%d";
+        }
+        ifr.ifr_flags |= IFF_NO_PI;
+
+        if (tun != SSH_TUNID_ANY) {
+                if (tun > SSH_TUNID_MAX) {
+                        debug("%s: invalid tunnel id %x: %s", __func__,
+                            tun, strerror(errno));
+                        goto failed;
+                }
+                snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), name, tun);
+        }
+
+        if (ioctl(fd, TUNSETIFF, &ifr) == -1) {
+                debug("%s: failed to configure tunnel (mode %d): %s", __func__,
+                    mode, strerror(errno));
+                goto failed;
+        }
+
+        if (tun == SSH_TUNID_ANY)
+                debug("%s: tunnel mode %d fd %d", __func__, mode, fd);
+        else
+                debug("%s: %s mode %d fd %d", __func__, ifr.ifr_name, mode, fd);
+
+        if (ifname != NULL && (*ifname = strdup(ifr.ifr_name)))
+                goto failed;
+
+        return (fd);
+
+ failed:
+        close(fd);
+        return (-1);
+}
+#endif /* SSH_TUN_LINUX */
+
+#ifdef SSH_TUN_FREEBSD
+#include <sys/socket.h>
+#include <net/if.h>
+
+#ifdef HAVE_NET_IF_TUN_H
+#include <net/if_tun.h>
+#endif
+
+int
+sys_tun_open(int tun, int mode, char **ifname)
+{
+        struct ifreq ifr;
+        char name[100];
+        int fd = -1, sock, flag;
+        const char *tunbase = "tun";
+
+        if (ifname != NULL)
+                *ifname = NULL;
+
+        if (mode == SSH_TUNMODE_ETHERNET) {
+#ifdef SSH_TUN_NO_L2
+                debug("%s: no layer 2 tunnelling support", __func__);
+                return (-1);
+#else
+                tunbase = "tap";
+#endif
+        }
+
+        /* Open the tunnel device */
+        if (tun <= SSH_TUNID_MAX) {
+                snprintf(name, sizeof(name), "/dev/%s%d", tunbase, tun);
+                fd = open(name, O_RDWR);
+        } else if (tun == SSH_TUNID_ANY) {
+                for (tun = 100; tun >= 0; tun--) {
+                        snprintf(name, sizeof(name), "/dev/%s%d",
+                            tunbase, tun);
+                        if ((fd = open(name, O_RDWR)) >= 0)
+                                break;
+                }
+        } else {
+                debug("%s: invalid tunnel %u\n", __func__, tun);
+                return (-1);
+        }
+
+        if (fd < 0) {
+                debug("%s: %s open failed: %s", __func__, name,
+                    strerror(errno));
+                return (-1);
+        }
+
+        /* Turn on tunnel headers */
+        flag = 1;
+#if defined(TUNSIFHEAD) && !defined(SSH_TUN_PREPEND_AF)
+        if (mode != SSH_TUNMODE_ETHERNET &&
+            ioctl(fd, TUNSIFHEAD, &flag) == -1) {
+                debug("%s: ioctl(%d, TUNSIFHEAD, 1): %s", __func__, fd,
+                    strerror(errno));
+                close(fd);
+        }
+#endif
+
+        debug("%s: %s mode %d fd %d", __func__, name, mode, fd);
+
+        /* Set the tunnel device operation mode */
+        snprintf(ifr.ifr_name, sizeof(ifr.ifr_name), "%s%d", tunbase, tun);
+        if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) == -1)
+                goto failed;
+
+        if (ioctl(sock, SIOCGIFFLAGS, &ifr) == -1)
+                goto failed;
+        if ((ifr.ifr_flags & IFF_UP) == 0) {
+                ifr.ifr_flags |= IFF_UP;
+                if (ioctl(sock, SIOCSIFFLAGS, &ifr) == -1)
+                        goto failed;
+        }
+
+        if (ifname != NULL && (*ifname = strdup(ifr.ifr_name)))
+                goto failed;
+
+        close(sock);
+        return (fd);
+
+ failed:
+        if (fd >= 0)
+                close(fd);
+        if (sock >= 0)
+                close(sock);
+        debug("%s: failed to set %s mode %d: %s", __func__, name,
+            mode, strerror(errno));
+        return (-1);
+}
+#endif /* SSH_TUN_FREEBSD */
+
+/*
+ * System-specific channel filters
+ */
+
+#if defined(SSH_TUN_FILTER)
+/*
+ * The tunnel forwarding protocol prepends the address family of forwarded
+ * IP packets using OpenBSD's numbers.
+ */
+#define OPENBSD_AF_INET         2
+#define OPENBSD_AF_INET6        24
+
+int
+sys_tun_infilter(struct ssh *ssh, struct Channel *c, char *buf, int _len)
+{
+        int r;
+        size_t len;
+        char *ptr = buf;
+#if defined(SSH_TUN_PREPEND_AF)
+        char rbuf[CHAN_RBUF];
+        struct ip iph;
+#endif
+#if defined(SSH_TUN_PREPEND_AF) || defined(SSH_TUN_COMPAT_AF)
+        u_int32_t af;
+#endif
+
+        /* XXX update channel input filter API to use unsigned length */
+        if (_len < 0)
+                return -1;
+        len = _len;
+
+#if defined(SSH_TUN_PREPEND_AF)
+        if (len <= sizeof(iph) || len > sizeof(rbuf) - 4)
+                return -1;
+        /* Determine address family from packet IP header. */
+        memcpy(&iph, buf, sizeof(iph));
+        af = iph.ip_v == 6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET;
+        /* Prepend address family to packet using OpenBSD constants */
+        memcpy(rbuf + 4, buf, len);
+        len += 4;
+        POKE_U32(rbuf, af);
+        ptr = rbuf;
+#elif defined(SSH_TUN_COMPAT_AF)
+        /* Convert existing address family header to OpenBSD value */
+        if (len <= 4)
+                return -1;
+        af = PEEK_U32(buf);
+        /* Put it back */
+        POKE_U32(buf, af == AF_INET6 ? OPENBSD_AF_INET6 : OPENBSD_AF_INET);
+#endif
+
+        if ((r = sshbuf_put_string(c->input, ptr, len)) != 0)
+                fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        return (0);
+}
+
+u_char *
+sys_tun_outfilter(struct ssh *ssh, struct Channel *c,
+    u_char **data, size_t *dlen)
+{
+        u_char *buf;
+        u_int32_t af;
+        int r;
+
+        /* XXX new API is incompatible with this signature. */
+        if ((r = sshbuf_get_string(c->output, data, dlen)) != 0)
+                fatal("%s: buffer error: %s", __func__, ssh_err(r));
+        if (*dlen < sizeof(af))
+                return (NULL);
+        buf = *data;
+
+#if defined(SSH_TUN_PREPEND_AF)
+        /* skip address family */
+        *dlen -= sizeof(af);
+        buf = *data + sizeof(af);
+#elif defined(SSH_TUN_COMPAT_AF)
+        /* translate address family */
+        af = (PEEK_U32(buf) == OPENBSD_AF_INET6) ? AF_INET6 : AF_INET;
+        POKE_U32(buf, af);
+#endif
+        return (buf);
+}
+#endif /* SSH_TUN_FILTER */