/* * QEMU System Emulator * * Copyright (c) 2003-2008 Fabrice Bellard * Copyright (c) 2009 Red Hat, Inc. * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ #include "tap_int.h" #include "config-host.h" #include <sys/ioctl.h> #include <sys/stat.h> #include <sys/wait.h> #include <sys/socket.h> #include <net/if.h> #include "net/net.h" #include "clients.h" #include "monitor/monitor.h" #include "sysemu/sysemu.h" #include "qemu-common.h" #include "qemu/error-report.h" #include "net/tap.h" #include "hw/vhost_net.h" /* Maximum GSO packet size (64k) plus plenty of room for * the ethernet and virtio_net headers */ #define TAP_BUFSIZE (4096 + 65536) typedef struct TAPState { NetClientState nc; int fd; char down_script[1024]; char down_script_arg[128]; uint8_t buf[TAP_BUFSIZE]; unsigned int read_poll : 1; unsigned int write_poll : 1; unsigned int using_vnet_hdr : 1; unsigned int has_ufo: 1; VHostNetState *vhost_net; unsigned host_vnet_hdr_len; } TAPState; static int launch_script(const char *setup_script, const char *ifname, int fd); static int tap_can_send(void *opaque); static void tap_send(void *opaque); static void tap_writable(void *opaque); static void tap_update_fd_handler(TAPState *s) { qemu_set_fd_handler2(s->fd, s->read_poll ? tap_can_send : NULL, s->read_poll ? tap_send : NULL, s->write_poll ? tap_writable : NULL, s); } static void tap_read_poll(TAPState *s, int enable) { s->read_poll = !!enable; tap_update_fd_handler(s); } static void tap_write_poll(TAPState *s, int enable) { s->write_poll = !!enable; tap_update_fd_handler(s); } static void tap_writable(void *opaque) { TAPState *s = opaque; tap_write_poll(s, 0); qemu_flush_queued_packets(&s->nc); } static ssize_t tap_write_packet(TAPState *s, const struct iovec *iov, int iovcnt) { ssize_t len; do { len = writev(s->fd, iov, iovcnt); } while (len == -1 && errno == EINTR); if (len == -1 && errno == EAGAIN) { tap_write_poll(s, 1); return 0; } return len; } static ssize_t tap_receive_iov(NetClientState *nc, const struct iovec *iov, int iovcnt) { TAPState *s = DO_UPCAST(TAPState, nc, nc); const struct iovec *iovp = iov; struct iovec iov_copy[iovcnt + 1]; struct virtio_net_hdr_mrg_rxbuf hdr = { }; if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { iov_copy[0].iov_base = &hdr; iov_copy[0].iov_len = s->host_vnet_hdr_len; memcpy(&iov_copy[1], iov, iovcnt * sizeof(*iov)); iovp = iov_copy; iovcnt++; } return tap_write_packet(s, iovp, iovcnt); } static ssize_t tap_receive_raw(NetClientState *nc, const uint8_t *buf, size_t size) { TAPState *s = DO_UPCAST(TAPState, nc, nc); struct iovec iov[2]; int iovcnt = 0; struct virtio_net_hdr_mrg_rxbuf hdr = { }; if (s->host_vnet_hdr_len) { iov[iovcnt].iov_base = &hdr; iov[iovcnt].iov_len = s->host_vnet_hdr_len; iovcnt++; } iov[iovcnt].iov_base = (char *)buf; iov[iovcnt].iov_len = size; iovcnt++; return tap_write_packet(s, iov, iovcnt); } static ssize_t tap_receive(NetClientState *nc, const uint8_t *buf, size_t size) { TAPState *s = DO_UPCAST(TAPState, nc, nc); struct iovec iov[1]; if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { return tap_receive_raw(nc, buf, size); } iov[0].iov_base = (char *)buf; iov[0].iov_len = size; return tap_write_packet(s, iov, 1); } static int tap_can_send(void *opaque) { TAPState *s = opaque; return qemu_can_send_packet(&s->nc); } #ifndef __sun__ ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen) { return read(tapfd, buf, maxlen); } #endif static void tap_send_completed(NetClientState *nc, ssize_t len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); tap_read_poll(s, 1); } static void tap_send(void *opaque) { TAPState *s = opaque; int size; do { uint8_t *buf = s->buf; size = tap_read_packet(s->fd, s->buf, sizeof(s->buf)); if (size <= 0) { break; } if (s->host_vnet_hdr_len && !s->using_vnet_hdr) { buf += s->host_vnet_hdr_len; size -= s->host_vnet_hdr_len; } size = qemu_send_packet_async(&s->nc, buf, size, tap_send_completed); if (size == 0) { tap_read_poll(s, 0); } } while (size > 0 && qemu_can_send_packet(&s->nc)); } int tap_has_ufo(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); return s->has_ufo; } int tap_has_vnet_hdr(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); return !!s->host_vnet_hdr_len; } int tap_has_vnet_hdr_len(NetClientState *nc, int len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); return tap_probe_vnet_hdr_len(s->fd, len); } void tap_set_vnet_hdr_len(NetClientState *nc, int len) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); assert(len == sizeof(struct virtio_net_hdr_mrg_rxbuf) || len == sizeof(struct virtio_net_hdr)); tap_fd_set_vnet_hdr_len(s->fd, len); s->host_vnet_hdr_len = len; } void tap_using_vnet_hdr(NetClientState *nc, int using_vnet_hdr) { TAPState *s = DO_UPCAST(TAPState, nc, nc); using_vnet_hdr = using_vnet_hdr != 0; assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); assert(!!s->host_vnet_hdr_len == using_vnet_hdr); s->using_vnet_hdr = using_vnet_hdr; } void tap_set_offload(NetClientState *nc, int csum, int tso4, int tso6, int ecn, int ufo) { TAPState *s = DO_UPCAST(TAPState, nc, nc); if (s->fd < 0) { return; } tap_fd_set_offload(s->fd, csum, tso4, tso6, ecn, ufo); } static void tap_cleanup(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); if (s->vhost_net) { vhost_net_cleanup(s->vhost_net); s->vhost_net = NULL; } qemu_purge_queued_packets(nc); if (s->down_script[0]) launch_script(s->down_script, s->down_script_arg, s->fd); tap_read_poll(s, 0); tap_write_poll(s, 0); close(s->fd); s->fd = -1; } static void tap_poll(NetClientState *nc, bool enable) { TAPState *s = DO_UPCAST(TAPState, nc, nc); tap_read_poll(s, enable); tap_write_poll(s, enable); } int tap_get_fd(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); return s->fd; } /* fd support */ static NetClientInfo net_tap_info = { .type = NET_CLIENT_OPTIONS_KIND_TAP, .size = sizeof(TAPState), .receive = tap_receive, .receive_raw = tap_receive_raw, .receive_iov = tap_receive_iov, .poll = tap_poll, .cleanup = tap_cleanup, }; static TAPState *net_tap_fd_init(NetClientState *peer, const char *model, const char *name, int fd, int vnet_hdr) { NetClientState *nc; TAPState *s; nc = qemu_new_net_client(&net_tap_info, peer, model, name); s = DO_UPCAST(TAPState, nc, nc); s->fd = fd; s->host_vnet_hdr_len = vnet_hdr ? sizeof(struct virtio_net_hdr) : 0; s->using_vnet_hdr = 0; s->has_ufo = tap_probe_has_ufo(s->fd); tap_set_offload(&s->nc, 0, 0, 0, 0, 0); /* * Make sure host header length is set correctly in tap: * it might have been modified by another instance of qemu. */ if (tap_probe_vnet_hdr_len(s->fd, s->host_vnet_hdr_len)) { tap_fd_set_vnet_hdr_len(s->fd, s->host_vnet_hdr_len); } tap_read_poll(s, 1); s->vhost_net = NULL; return s; } static int launch_script(const char *setup_script, const char *ifname, int fd) { int pid, status; char *args[3]; char **parg; /* try to launch network script */ pid = fork(); if (pid == 0) { int open_max = sysconf(_SC_OPEN_MAX), i; for (i = 0; i < open_max; i++) { if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO && i != fd) { close(i); } } parg = args; *parg++ = (char *)setup_script; *parg++ = (char *)ifname; *parg = NULL; execv(setup_script, args); _exit(1); } else if (pid > 0) { while (waitpid(pid, &status, 0) != pid) { /* loop */ } if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { return 0; } } fprintf(stderr, "%s: could not launch network script\n", setup_script); return -1; } static int recv_fd(int c) { int fd; uint8_t msgbuf[CMSG_SPACE(sizeof(fd))]; struct msghdr msg = { .msg_control = msgbuf, .msg_controllen = sizeof(msgbuf), }; struct cmsghdr *cmsg; struct iovec iov; uint8_t req[1]; ssize_t len; cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_level = SOL_SOCKET; cmsg->cmsg_type = SCM_RIGHTS; cmsg->cmsg_len = CMSG_LEN(sizeof(fd)); msg.msg_controllen = cmsg->cmsg_len; iov.iov_base = req; iov.iov_len = sizeof(req); msg.msg_iov = &iov; msg.msg_iovlen = 1; len = recvmsg(c, &msg, 0); if (len > 0) { memcpy(&fd, CMSG_DATA(cmsg), sizeof(fd)); return fd; } return len; } static int net_bridge_run_helper(const char *helper, const char *bridge) { sigset_t oldmask, mask; int pid, status; char *args[5]; char **parg; int sv[2]; sigemptyset(&mask); sigaddset(&mask, SIGCHLD); sigprocmask(SIG_BLOCK, &mask, &oldmask); if (socketpair(PF_UNIX, SOCK_STREAM, 0, sv) == -1) { return -1; } /* try to launch bridge helper */ pid = fork(); if (pid == 0) { int open_max = sysconf(_SC_OPEN_MAX), i; char fd_buf[6+10]; char br_buf[6+IFNAMSIZ] = {0}; char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15]; for (i = 0; i < open_max; i++) { if (i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO && i != sv[1]) { close(i); } } snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]); if (strrchr(helper, ' ') || strrchr(helper, '\t')) { /* assume helper is a command */ if (strstr(helper, "--br=") == NULL) { snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); } snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s", helper, "--use-vnet", fd_buf, br_buf); parg = args; *parg++ = (char *)"sh"; *parg++ = (char *)"-c"; *parg++ = helper_cmd; *parg++ = NULL; execv("/bin/sh", args); } else { /* assume helper is just the executable path name */ snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge); parg = args; *parg++ = (char *)helper; *parg++ = (char *)"--use-vnet"; *parg++ = fd_buf; *parg++ = br_buf; *parg++ = NULL; execv(helper, args); } _exit(1); } else if (pid > 0) { int fd; close(sv[1]); do { fd = recv_fd(sv[0]); } while (fd == -1 && errno == EINTR); close(sv[0]); while (waitpid(pid, &status, 0) != pid) { /* loop */ } sigprocmask(SIG_SETMASK, &oldmask, NULL); if (fd < 0) { fprintf(stderr, "failed to recv file descriptor\n"); return -1; } if (WIFEXITED(status) && WEXITSTATUS(status) == 0) { return fd; } } fprintf(stderr, "failed to launch bridge helper\n"); return -1; } int net_init_bridge(const NetClientOptions *opts, const char *name, NetClientState *peer) { const NetdevBridgeOptions *bridge; const char *helper, *br; TAPState *s; int fd, vnet_hdr; assert(opts->kind == NET_CLIENT_OPTIONS_KIND_BRIDGE); bridge = opts->bridge; helper = bridge->has_helper ? bridge->helper : DEFAULT_BRIDGE_HELPER; br = bridge->has_br ? bridge->br : DEFAULT_BRIDGE_INTERFACE; fd = net_bridge_run_helper(helper, br); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); s = net_tap_fd_init(peer, "bridge", name, fd, vnet_hdr); if (!s) { close(fd); return -1; } snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s,br=%s", helper, br); return 0; } static int net_tap_init(const NetdevTapOptions *tap, int *vnet_hdr, const char *setup_script, char *ifname, size_t ifname_sz) { int fd, vnet_hdr_required; if (tap->has_ifname) { pstrcpy(ifname, ifname_sz, tap->ifname); } else { assert(ifname_sz > 0); ifname[0] = '\0'; } if (tap->has_vnet_hdr) { *vnet_hdr = tap->vnet_hdr; vnet_hdr_required = *vnet_hdr; } else { *vnet_hdr = 1; vnet_hdr_required = 0; } TFR(fd = tap_open(ifname, ifname_sz, vnet_hdr, vnet_hdr_required)); if (fd < 0) { return -1; } if (setup_script && setup_script[0] != '\0' && strcmp(setup_script, "no") != 0 && launch_script(setup_script, ifname, fd)) { close(fd); return -1; } return fd; } int net_init_tap(const NetClientOptions *opts, const char *name, NetClientState *peer) { const NetdevTapOptions *tap; int fd, vnet_hdr = 0; const char *model; TAPState *s; /* for the no-fd, no-helper case */ const char *script = NULL; /* suppress wrong "uninit'd use" gcc warning */ char ifname[128]; assert(opts->kind == NET_CLIENT_OPTIONS_KIND_TAP); tap = opts->tap; if (tap->has_fd) { if (tap->has_ifname || tap->has_script || tap->has_downscript || tap->has_vnet_hdr || tap->has_helper) { error_report("ifname=, script=, downscript=, vnet_hdr=, " "and helper= are invalid with fd="); return -1; } fd = monitor_handle_fd_param(cur_mon, tap->fd); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); model = "tap"; } else if (tap->has_helper) { if (tap->has_ifname || tap->has_script || tap->has_downscript || tap->has_vnet_hdr) { error_report("ifname=, script=, downscript=, and vnet_hdr= " "are invalid with helper="); return -1; } fd = net_bridge_run_helper(tap->helper, DEFAULT_BRIDGE_INTERFACE); if (fd == -1) { return -1; } fcntl(fd, F_SETFL, O_NONBLOCK); vnet_hdr = tap_probe_vnet_hdr(fd); model = "bridge"; } else { script = tap->has_script ? tap->script : DEFAULT_NETWORK_SCRIPT; fd = net_tap_init(tap, &vnet_hdr, script, ifname, sizeof ifname); if (fd == -1) { return -1; } model = "tap"; } s = net_tap_fd_init(peer, model, name, fd, vnet_hdr); if (!s) { close(fd); return -1; } if (tap_set_sndbuf(s->fd, tap) < 0) { return -1; } if (tap->has_fd) { snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd); } else if (tap->has_helper) { snprintf(s->nc.info_str, sizeof(s->nc.info_str), "helper=%s", tap->helper); } else { const char *downscript; downscript = tap->has_downscript ? tap->downscript : DEFAULT_NETWORK_DOWN_SCRIPT; snprintf(s->nc.info_str, sizeof(s->nc.info_str), "ifname=%s,script=%s,downscript=%s", ifname, script, downscript); if (strcmp(downscript, "no") != 0) { snprintf(s->down_script, sizeof(s->down_script), "%s", downscript); snprintf(s->down_script_arg, sizeof(s->down_script_arg), "%s", ifname); } } if (tap->has_vhost ? tap->vhost : tap->has_vhostfd || (tap->has_vhostforce && tap->vhostforce)) { int vhostfd; if (tap->has_vhostfd) { vhostfd = monitor_handle_fd_param(cur_mon, tap->vhostfd); if (vhostfd == -1) { return -1; } } else { vhostfd = -1; } s->vhost_net = vhost_net_init(&s->nc, vhostfd, tap->has_vhostforce && tap->vhostforce); if (!s->vhost_net) { error_report("vhost-net requested but could not be initialized"); return -1; } } else if (tap->has_vhostfd) { error_report("vhostfd= is not valid without vhost"); return -1; } return 0; } VHostNetState *tap_get_vhost_net(NetClientState *nc) { TAPState *s = DO_UPCAST(TAPState, nc, nc); assert(nc->info->type == NET_CLIENT_OPTIONS_KIND_TAP); return s->vhost_net; }