1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2016 Intel Corporation
3 */
4
5 #include <unistd.h>
6 #include <sys/types.h>
7 #include <sys/stat.h>
8 #include <fcntl.h>
9 #include <net/if.h>
10 #include <net/if_arp.h>
11 #include <errno.h>
12 #include <string.h>
13 #include <limits.h>
14
15 #include <rte_ether.h>
16
17 #include "vhost_kernel_tap.h"
18 #include "../virtio_logs.h"
19 #include "../virtio_pci.h"
20
21 int
vhost_kernel_tap_set_offload(int fd,uint64_t features)22 vhost_kernel_tap_set_offload(int fd, uint64_t features)
23 {
24 unsigned int offload = 0;
25
26 if (features & (1ULL << VIRTIO_NET_F_GUEST_CSUM)) {
27 offload |= TUN_F_CSUM;
28 if (features & (1ULL << VIRTIO_NET_F_GUEST_TSO4))
29 offload |= TUN_F_TSO4;
30 if (features & (1ULL << VIRTIO_NET_F_GUEST_TSO6))
31 offload |= TUN_F_TSO6;
32 if (features & ((1ULL << VIRTIO_NET_F_GUEST_TSO4) |
33 (1ULL << VIRTIO_NET_F_GUEST_TSO6)) &&
34 (features & (1ULL << VIRTIO_NET_F_GUEST_ECN)))
35 offload |= TUN_F_TSO_ECN;
36 if (features & (1ULL << VIRTIO_NET_F_GUEST_UFO))
37 offload |= TUN_F_UFO;
38 }
39
40 /* Check if our kernel supports TUNSETOFFLOAD */
41 if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
42 PMD_DRV_LOG(ERR, "Kernel doesn't support TUNSETOFFLOAD\n");
43 return -ENOTSUP;
44 }
45
46 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
47 offload &= ~TUN_F_UFO;
48 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
49 PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s\n",
50 strerror(errno));
51 return -1;
52 }
53 }
54
55 return 0;
56 }
57
58 int
vhost_kernel_tap_set_queue(int fd,bool attach)59 vhost_kernel_tap_set_queue(int fd, bool attach)
60 {
61 struct ifreq ifr = {
62 .ifr_flags = attach ? IFF_ATTACH_QUEUE : IFF_DETACH_QUEUE,
63 };
64
65 return ioctl(fd, TUNSETQUEUE, &ifr);
66 }
67
68 int
vhost_kernel_open_tap(char ** p_ifname,int hdr_size,int req_mq,const char * mac,uint64_t features)69 vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq,
70 const char *mac, uint64_t features)
71 {
72 unsigned int tap_features;
73 char *tap_name = NULL;
74 int sndbuf = INT_MAX;
75 struct ifreq ifr;
76 int tapfd;
77 int ret;
78
79 /* TODO:
80 * 1. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len
81 * 2. get number of memory regions from vhost module parameter
82 * max_mem_regions, supported in newer version linux kernel
83 */
84 tapfd = open(PATH_NET_TUN, O_RDWR);
85 if (tapfd < 0) {
86 PMD_DRV_LOG(ERR, "fail to open %s: %s",
87 PATH_NET_TUN, strerror(errno));
88 return -1;
89 }
90
91 /* Construct ifr */
92 memset(&ifr, 0, sizeof(ifr));
93 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
94
95 if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) {
96 PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
97 goto error;
98 }
99 if (tap_features & IFF_ONE_QUEUE)
100 ifr.ifr_flags |= IFF_ONE_QUEUE;
101
102 /* Let tap instead of vhost-net handle vnet header, as the latter does
103 * not support offloading. And in this case, we should not set feature
104 * bit VHOST_NET_F_VIRTIO_NET_HDR.
105 */
106 if (tap_features & IFF_VNET_HDR) {
107 ifr.ifr_flags |= IFF_VNET_HDR;
108 } else {
109 PMD_DRV_LOG(ERR, "TAP does not support IFF_VNET_HDR");
110 goto error;
111 }
112
113 if (req_mq)
114 ifr.ifr_flags |= IFF_MULTI_QUEUE;
115
116 if (*p_ifname)
117 strncpy(ifr.ifr_name, *p_ifname, IFNAMSIZ - 1);
118 else
119 strncpy(ifr.ifr_name, "tap%d", IFNAMSIZ - 1);
120 if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
121 PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno));
122 goto error;
123 }
124
125 tap_name = strdup(ifr.ifr_name);
126 if (!tap_name) {
127 PMD_DRV_LOG(ERR, "strdup ifname failed: %s", strerror(errno));
128 goto error;
129 }
130
131 if (fcntl(tapfd, F_SETFL, O_NONBLOCK) < 0) {
132 PMD_DRV_LOG(ERR, "fcntl tapfd failed: %s", strerror(errno));
133 goto error;
134 }
135
136 if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) {
137 PMD_DRV_LOG(ERR, "TUNSETVNETHDRSZ failed: %s", strerror(errno));
138 goto error;
139 }
140
141 if (ioctl(tapfd, TUNSETSNDBUF, &sndbuf) < 0) {
142 PMD_DRV_LOG(ERR, "TUNSETSNDBUF failed: %s", strerror(errno));
143 goto error;
144 }
145
146 ret = vhost_kernel_tap_set_offload(tapfd, features);
147 if (ret < 0 && ret != -ENOTSUP)
148 goto error;
149
150 memset(&ifr, 0, sizeof(ifr));
151 ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
152 memcpy(ifr.ifr_hwaddr.sa_data, mac, RTE_ETHER_ADDR_LEN);
153 if (ioctl(tapfd, SIOCSIFHWADDR, (void *)&ifr) == -1) {
154 PMD_DRV_LOG(ERR, "SIOCSIFHWADDR failed: %s", strerror(errno));
155 goto error;
156 }
157
158 free(*p_ifname);
159 *p_ifname = tap_name;
160
161 return tapfd;
162 error:
163 free(tap_name);
164 close(tapfd);
165 return -1;
166 }
167