Initial commit of d32e8d0b8d9e0ef7cf7ab2e74548982972789dfc from qemu-kvm

1 files changed, 525 insertions, 0 deletions

diff --git a/net/tap.c b/net/tap.c
new file mode 100644
index 0000000..b8cd252
--- /dev/null
+++ b/net/tap.c
@@ -0,0 +1,525 @@
+/*
+ * 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 "net/tap.h"
+
+#include "config-host.h"
+
+#include <signal.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#include "net.h"
+#include "sysemu.h"
+#include "qemu-char.h"
+#include "qemu-common.h"
+#include "qemu-error.h"
+
+#include "net/tap-linux.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 {
+    VLANClientState 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(VLANClientState *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(VLANClientState *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(VLANClientState *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(VLANClientState *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(VLANClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+
+    return s->has_ufo;
+}
+
+int tap_has_vnet_hdr(VLANClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+
+    return !!s->host_vnet_hdr_len;
+}
+
+int tap_has_vnet_hdr_len(VLANClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+
+    return tap_probe_vnet_hdr_len(s->fd, len);
+}
+
+void tap_set_vnet_hdr_len(VLANClientState *nc, int len)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+
+    assert(nc->info->type == NET_CLIENT_TYPE_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(VLANClientState *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_TYPE_TAP);
+    assert(!!s->host_vnet_hdr_len == using_vnet_hdr);
+
+    s->using_vnet_hdr = using_vnet_hdr;
+}
+
+void tap_set_offload(VLANClientState *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(VLANClientState *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(VLANClientState *nc, bool enable)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    tap_read_poll(s, enable);
+    tap_write_poll(s, enable);
+}
+
+int tap_get_fd(VLANClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+    return s->fd;
+}
+
+/* fd support */
+
+static NetClientInfo net_tap_info = {
+    .type = NET_CLIENT_TYPE_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(VLANState *vlan,
+                                 const char *model,
+                                 const char *name,
+                                 int fd,
+                                 int vnet_hdr)
+{
+    VLANClientState *nc;
+    TAPState *s;
+
+    nc = qemu_new_net_client(&net_tap_info, vlan, NULL, 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);
+    tap_read_poll(s, 1);
+    s->vhost_net = NULL;
+    return s;
+}
+
+static int launch_script(const char *setup_script, const char *ifname, int fd)
+{
+    sigset_t oldmask, mask;
+    int pid, status;
+    char *args[3];
+    char **parg;
+
+    sigemptyset(&mask);
+    sigaddset(&mask, SIGCHLD);
+    sigprocmask(SIG_BLOCK, &mask, &oldmask);
+
+    /* 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 */
+        }
+        sigprocmask(SIG_SETMASK, &oldmask, NULL);
+
+        if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
+            return 0;
+        }
+    }
+    fprintf(stderr, "%s: could not launch network script\n", setup_script);
+    return -1;
+}
+
+static int net_tap_init(QemuOpts *opts, int *vnet_hdr)
+{
+    int fd, vnet_hdr_required;
+    char ifname[128] = {0,};
+    const char *setup_script;
+
+    if (qemu_opt_get(opts, "ifname")) {
+        pstrcpy(ifname, sizeof(ifname), qemu_opt_get(opts, "ifname"));
+    }
+
+    *vnet_hdr = qemu_opt_get_bool(opts, "vnet_hdr", 1);
+    if (qemu_opt_get(opts, "vnet_hdr")) {
+        vnet_hdr_required = *vnet_hdr;
+    } else {
+        vnet_hdr_required = 0;
+    }
+
+    TFR(fd = tap_open(ifname, sizeof(ifname), vnet_hdr, vnet_hdr_required));
+    if (fd < 0) {
+        return -1;
+    }
+
+    setup_script = qemu_opt_get(opts, "script");
+    if (setup_script &&
+        setup_script[0] != '\0' &&
+        strcmp(setup_script, "no") != 0 &&
+        launch_script(setup_script, ifname, fd)) {
+        close(fd);
+        return -1;
+    }
+
+    qemu_opt_set(opts, "ifname", ifname);
+
+    return fd;
+}
+
+int net_init_tap(QemuOpts *opts, Monitor *mon, const char *name, VLANState *vlan)
+{
+    TAPState *s;
+    int fd, vnet_hdr = 0;
+
+    if (qemu_opt_get(opts, "fd")) {
+        if (qemu_opt_get(opts, "ifname") ||
+            qemu_opt_get(opts, "script") ||
+            qemu_opt_get(opts, "downscript") ||
+            qemu_opt_get(opts, "vnet_hdr")) {
+            error_report("ifname=, script=, downscript= and vnet_hdr= is invalid with fd=");
+            return -1;
+        }
+
+        fd = net_handle_fd_param(mon, qemu_opt_get(opts, "fd"));
+        if (fd == -1) {
+            return -1;
+        }
+
+        fcntl(fd, F_SETFL, O_NONBLOCK);
+
+        vnet_hdr = tap_probe_vnet_hdr(fd);
+    } else {
+        if (!qemu_opt_get(opts, "script")) {
+            qemu_opt_set(opts, "script", DEFAULT_NETWORK_SCRIPT);
+        }
+
+        if (!qemu_opt_get(opts, "downscript")) {
+            qemu_opt_set(opts, "downscript", DEFAULT_NETWORK_DOWN_SCRIPT);
+        }
+
+        fd = net_tap_init(opts, &vnet_hdr);
+        if (fd == -1) {
+            return -1;
+        }
+    }
+
+    s = net_tap_fd_init(vlan, "tap", name, fd, vnet_hdr);
+    if (!s) {
+        close(fd);
+        return -1;
+    }
+
+    if (tap_set_sndbuf(s->fd, opts) < 0) {
+        return -1;
+    }
+
+    if (qemu_opt_get(opts, "fd")) {
+        snprintf(s->nc.info_str, sizeof(s->nc.info_str), "fd=%d", fd);
+    } else {
+        const char *ifname, *script, *downscript;
+
+        ifname     = qemu_opt_get(opts, "ifname");
+        script     = qemu_opt_get(opts, "script");
+        downscript = qemu_opt_get(opts, "downscript");
+
+        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 (qemu_opt_get_bool(opts, "vhost", !!qemu_opt_get(opts, "vhostfd") ||
+                          qemu_opt_get_bool(opts, "vhostforce", false))) {
+        int vhostfd, r;
+        bool force = qemu_opt_get_bool(opts, "vhostforce", false);
+        if (qemu_opt_get(opts, "vhostfd")) {
+            r = net_handle_fd_param(mon, qemu_opt_get(opts, "vhostfd"));
+            if (r == -1) {
+                return -1;
+            }
+            vhostfd = r;
+        } else {
+            vhostfd = -1;
+        }
+        s->vhost_net = vhost_net_init(&s->nc, vhostfd, force);
+        if (!s->vhost_net) {
+            error_report("vhost-net requested but could not be initialized");
+            return -1;
+        }
+    } else if (qemu_opt_get(opts, "vhostfd")) {
+        error_report("vhostfd= is not valid without vhost");
+        return -1;
+    }
+
+    return 0;
+}
+
+VHostNetState *tap_get_vhost_net(VLANClientState *nc)
+{
+    TAPState *s = DO_UPCAST(TAPState, nc, nc);
+    assert(nc->info->type == NET_CLIENT_TYPE_TAP);
+    return s->vhost_net;
+}