diff options
Diffstat (limited to 'openbsd-compat/port-net.c')
| -rw-r--r-- | openbsd-compat/port-net.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/openbsd-compat/port-net.c b/openbsd-compat/port-net.c new file mode 100644 index 0000000..bb53562 --- /dev/null +++ b/openbsd-compat/port-net.c @@ -0,0 +1,374 @@ +/* + * 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 file contains various portability code for network support, + * including tun/tap forwarding and routing domains. + */ + +#if defined(SYS_RDOMAIN_LINUX) || defined(SSH_TUN_LINUX) +#include <linux/if.h> +#endif + +#if defined(SYS_RDOMAIN_LINUX) +char * +sys_get_rdomain(int fd) +{ + char dev[IFNAMSIZ + 1]; + socklen_t len = sizeof(dev) - 1; + + if (getsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, dev, &len) == -1) { + error("%s: cannot determine VRF for fd=%d : %s", + __func__, fd, strerror(errno)); + return NULL; + } + dev[len] = '\0'; + return strdup(dev); +} + +int +sys_set_rdomain(int fd, const char *name) +{ + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, + name, strlen(name)) == -1) { + error("%s: setsockopt(%d, SO_BINDTODEVICE, %s): %s", + __func__, fd, name, strerror(errno)); + return -1; + } + return 0; +} + +int +sys_valid_rdomain(const char *name) +{ + int fd; + + /* + * This is a pretty crappy way to test. It would be better to + * check whether "name" represents a VRF device, but apparently + * that requires an rtnetlink transaction. + */ + if ((fd = socket(AF_INET, SOCK_STREAM, 0)) == -1) + return 0; + if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, + name, strlen(name)) == -1) { + close(fd); + return 0; + } + close(fd); + return 1; +} +#elif defined(SYS_RDOMAIN_XXX) +/* XXX examples */ +char * +sys_get_rdomain(int fd) +{ + return NULL; +} + +int +sys_set_rdomain(int fd, const char *name) +{ + return -1; +} + +int +valid_rdomain(const char *name) +{ + return 0; +} + +void +sys_set_process_rdomain(const char *name) +{ + fatal("%s: not supported", __func__); +} +#endif /* defined(SYS_RDOMAIN_XXX) */ + +/* + * 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_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)) == NULL) + 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)) == NULL) + 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 */ |