diff options
author | Yang Zhang <yang.z.zhang@intel.com> | 2015-08-28 09:58:54 +0800 |
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committer | Yang Zhang <yang.z.zhang@intel.com> | 2015-09-01 12:44:00 +0800 |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/net/tap-linux.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/net/tap-linux.c')
-rw-r--r-- | qemu/net/tap-linux.c | 314 |
1 files changed, 314 insertions, 0 deletions
diff --git a/qemu/net/tap-linux.c b/qemu/net/tap-linux.c new file mode 100644 index 000000000..394f2a646 --- /dev/null +++ b/qemu/net/tap-linux.c @@ -0,0 +1,314 @@ +/* + * 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 "tap-linux.h" +#include "net/tap.h" + +#include <net/if.h> +#include <sys/ioctl.h> + +#include "sysemu/sysemu.h" +#include "qemu-common.h" +#include "qemu/error-report.h" + +#define PATH_NET_TUN "/dev/net/tun" + +int tap_open(char *ifname, int ifname_size, int *vnet_hdr, + int vnet_hdr_required, int mq_required, Error **errp) +{ + struct ifreq ifr; + int fd, ret; + int len = sizeof(struct virtio_net_hdr); + unsigned int features; + + TFR(fd = open(PATH_NET_TUN, O_RDWR)); + if (fd < 0) { + error_setg_errno(errp, errno, "could not open %s", PATH_NET_TUN); + return -1; + } + memset(&ifr, 0, sizeof(ifr)); + ifr.ifr_flags = IFF_TAP | IFF_NO_PI; + + if (ioctl(fd, TUNGETFEATURES, &features) == -1) { + error_report("warning: TUNGETFEATURES failed: %s", strerror(errno)); + features = 0; + } + + if (features & IFF_ONE_QUEUE) { + ifr.ifr_flags |= IFF_ONE_QUEUE; + } + + if (*vnet_hdr) { + if (features & IFF_VNET_HDR) { + *vnet_hdr = 1; + ifr.ifr_flags |= IFF_VNET_HDR; + } else { + *vnet_hdr = 0; + } + + if (vnet_hdr_required && !*vnet_hdr) { + error_setg(errp, "vnet_hdr=1 requested, but no kernel " + "support for IFF_VNET_HDR available"); + close(fd); + return -1; + } + /* + * Make sure vnet header size has the default value: for a persistent + * tap it might have been modified e.g. by another instance of qemu. + * Ignore errors since old kernels do not support this ioctl: in this + * case the header size implicitly has the correct value. + */ + ioctl(fd, TUNSETVNETHDRSZ, &len); + } + + if (mq_required) { + if (!(features & IFF_MULTI_QUEUE)) { + error_setg(errp, "multiqueue required, but no kernel " + "support for IFF_MULTI_QUEUE available"); + close(fd); + return -1; + } else { + ifr.ifr_flags |= IFF_MULTI_QUEUE; + } + } + + if (ifname[0] != '\0') + pstrcpy(ifr.ifr_name, IFNAMSIZ, ifname); + else + pstrcpy(ifr.ifr_name, IFNAMSIZ, "tap%d"); + ret = ioctl(fd, TUNSETIFF, (void *) &ifr); + if (ret != 0) { + if (ifname[0] != '\0') { + error_setg_errno(errp, errno, "could not configure %s (%s)", + PATH_NET_TUN, ifr.ifr_name); + } else { + error_setg_errno(errp, errno, "could not configure %s", + PATH_NET_TUN); + } + close(fd); + return -1; + } + pstrcpy(ifname, ifname_size, ifr.ifr_name); + fcntl(fd, F_SETFL, O_NONBLOCK); + return fd; +} + +/* sndbuf implements a kind of flow control for tap. + * Unfortunately when it's enabled, and packets are sent + * to other guests on the same host, the receiver + * can lock up the transmitter indefinitely. + * + * To avoid packet loss, sndbuf should be set to a value lower than the tx + * queue capacity of any destination network interface. + * Ethernet NICs generally have txqueuelen=1000, so 1Mb is + * a good value, given a 1500 byte MTU. + */ +#define TAP_DEFAULT_SNDBUF 0 + +void tap_set_sndbuf(int fd, const NetdevTapOptions *tap, Error **errp) +{ + int sndbuf; + + sndbuf = !tap->has_sndbuf ? TAP_DEFAULT_SNDBUF : + tap->sndbuf > INT_MAX ? INT_MAX : + tap->sndbuf; + + if (!sndbuf) { + sndbuf = INT_MAX; + } + + if (ioctl(fd, TUNSETSNDBUF, &sndbuf) == -1 && tap->has_sndbuf) { + error_setg_errno(errp, errno, "TUNSETSNDBUF ioctl failed"); + } +} + +int tap_probe_vnet_hdr(int fd) +{ + struct ifreq ifr; + + if (ioctl(fd, TUNGETIFF, &ifr) != 0) { + error_report("TUNGETIFF ioctl() failed: %s", strerror(errno)); + return 0; + } + + return ifr.ifr_flags & IFF_VNET_HDR; +} + +int tap_probe_has_ufo(int fd) +{ + unsigned offload; + + offload = TUN_F_CSUM | TUN_F_UFO; + + if (ioctl(fd, TUNSETOFFLOAD, offload) < 0) + return 0; + + return 1; +} + +/* Verify that we can assign given length */ +int tap_probe_vnet_hdr_len(int fd, int len) +{ + int orig; + if (ioctl(fd, TUNGETVNETHDRSZ, &orig) == -1) { + return 0; + } + if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) { + return 0; + } + /* Restore original length: we can't handle failure. */ + if (ioctl(fd, TUNSETVNETHDRSZ, &orig) == -1) { + fprintf(stderr, "TUNGETVNETHDRSZ ioctl() failed: %s. Exiting.\n", + strerror(errno)); + abort(); + return -errno; + } + return 1; +} + +void tap_fd_set_vnet_hdr_len(int fd, int len) +{ + if (ioctl(fd, TUNSETVNETHDRSZ, &len) == -1) { + fprintf(stderr, "TUNSETVNETHDRSZ ioctl() failed: %s. Exiting.\n", + strerror(errno)); + abort(); + } +} + +int tap_fd_set_vnet_le(int fd, int is_le) +{ + int arg = is_le ? 1 : 0; + + if (!ioctl(fd, TUNSETVNETLE, &arg)) { + return 0; + } + + /* Check if our kernel supports TUNSETVNETLE */ + if (errno == EINVAL) { + return -errno; + } + + error_report("TUNSETVNETLE ioctl() failed: %s.\n", strerror(errno)); + abort(); +} + +int tap_fd_set_vnet_be(int fd, int is_be) +{ + int arg = is_be ? 1 : 0; + + if (!ioctl(fd, TUNSETVNETBE, &arg)) { + return 0; + } + + /* Check if our kernel supports TUNSETVNETBE */ + if (errno == EINVAL) { + return -errno; + } + + error_report("TUNSETVNETBE ioctl() failed: %s.\n", strerror(errno)); + abort(); +} + +void tap_fd_set_offload(int fd, int csum, int tso4, + int tso6, int ecn, int ufo) +{ + unsigned int offload = 0; + + /* Check if our kernel supports TUNSETOFFLOAD */ + if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) { + return; + } + + if (csum) { + offload |= TUN_F_CSUM; + if (tso4) + offload |= TUN_F_TSO4; + if (tso6) + offload |= TUN_F_TSO6; + if ((tso4 || tso6) && ecn) + offload |= TUN_F_TSO_ECN; + if (ufo) + offload |= TUN_F_UFO; + } + + if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) { + offload &= ~TUN_F_UFO; + if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) { + fprintf(stderr, "TUNSETOFFLOAD ioctl() failed: %s\n", + strerror(errno)); + } + } +} + +/* Enable a specific queue of tap. */ +int tap_fd_enable(int fd) +{ + struct ifreq ifr; + int ret; + + memset(&ifr, 0, sizeof(ifr)); + + ifr.ifr_flags = IFF_ATTACH_QUEUE; + ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr); + + if (ret != 0) { + error_report("could not enable queue"); + } + + return ret; +} + +/* Disable a specific queue of tap/ */ +int tap_fd_disable(int fd) +{ + struct ifreq ifr; + int ret; + + memset(&ifr, 0, sizeof(ifr)); + + ifr.ifr_flags = IFF_DETACH_QUEUE; + ret = ioctl(fd, TUNSETQUEUE, (void *) &ifr); + + if (ret != 0) { + error_report("could not disable queue"); + } + + return ret; +} + +int tap_fd_get_ifname(int fd, char *ifname) +{ + struct ifreq ifr; + + if (ioctl(fd, TUNGETIFF, &ifr) != 0) { + error_report("TUNGETIFF ioctl() failed: %s", + strerror(errno)); + return -1; + } + + pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name); + return 0; +} |