xref: /dpdk/drivers/net/virtio/virtio_user/vhost_kernel_tap.c (revision 666ff7763582bf2494e85b5175fc549ae89aa9fd)
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.h"
20 
21 
22 int
tap_support_features(unsigned int * tap_features)23 tap_support_features(unsigned int *tap_features)
24 {
25 	int tapfd;
26 
27 	tapfd = open(PATH_NET_TUN, O_RDWR);
28 	if (tapfd < 0) {
29 		PMD_DRV_LOG(ERR, "fail to open %s: %s",
30 			    PATH_NET_TUN, strerror(errno));
31 		return -1;
32 	}
33 
34 	if (ioctl(tapfd, TUNGETFEATURES, tap_features) == -1) {
35 		PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno));
36 		close(tapfd);
37 		return -1;
38 	}
39 
40 	close(tapfd);
41 	return 0;
42 }
43 
44 int
tap_open(const char * ifname,unsigned int r_flags,bool multi_queue)45 tap_open(const char *ifname, unsigned int r_flags, bool multi_queue)
46 {
47 	struct ifreq ifr;
48 	int tapfd;
49 
50 	tapfd = open(PATH_NET_TUN, O_RDWR);
51 	if (tapfd < 0) {
52 		PMD_DRV_LOG(ERR, "fail to open %s: %s", PATH_NET_TUN, strerror(errno));
53 		return -1;
54 	}
55 	if (fcntl(tapfd, F_SETFL, O_NONBLOCK) < 0) {
56 		PMD_DRV_LOG(ERR, "fcntl tapfd failed: %s", strerror(errno));
57 		close(tapfd);
58 		return -1;
59 	}
60 
61 retry_mono_q:
62 	memset(&ifr, 0, sizeof(ifr));
63 	strncpy(ifr.ifr_name, ifname, IFNAMSIZ - 1);
64 	ifr.ifr_flags = r_flags;
65 	if (multi_queue)
66 		ifr.ifr_flags |= IFF_MULTI_QUEUE;
67 	if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) {
68 		if (multi_queue) {
69 			PMD_DRV_LOG(DEBUG,
70 				"TUNSETIFF failed (will retry without IFF_MULTI_QUEUE): %s",
71 				strerror(errno));
72 			multi_queue = false;
73 			goto retry_mono_q;
74 		}
75 
76 		PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno));
77 		close(tapfd);
78 		tapfd = -1;
79 	}
80 	return tapfd;
81 }
82 
83 int
tap_get_name(int tapfd,char ** name)84 tap_get_name(int tapfd, char **name)
85 {
86 	struct ifreq ifr;
87 	int ret;
88 
89 	memset(&ifr, 0, sizeof(ifr));
90 	if (ioctl(tapfd, TUNGETIFF, (void *)&ifr) == -1) {
91 		PMD_DRV_LOG(ERR, "TUNGETIFF failed: %s", strerror(errno));
92 		return -1;
93 	}
94 	ret = asprintf(name, "%s", ifr.ifr_name);
95 	if (ret != -1)
96 		ret = 0;
97 	return ret;
98 }
99 
100 int
tap_get_flags(int tapfd,unsigned int * tap_flags)101 tap_get_flags(int tapfd, unsigned int *tap_flags)
102 {
103 	struct ifreq ifr;
104 
105 	memset(&ifr, 0, sizeof(ifr));
106 	if (ioctl(tapfd, TUNGETIFF, (void *)&ifr) == -1) {
107 		PMD_DRV_LOG(ERR, "TUNGETIFF failed: %s", strerror(errno));
108 		return -1;
109 	}
110 	*tap_flags = ifr.ifr_flags;
111 	return 0;
112 }
113 
114 int
tap_set_mac(int tapfd,uint8_t * mac)115 tap_set_mac(int tapfd, uint8_t *mac)
116 {
117 	struct ifreq ifr;
118 
119 	memset(&ifr, 0, sizeof(ifr));
120 	ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
121 	memcpy(ifr.ifr_hwaddr.sa_data, mac, RTE_ETHER_ADDR_LEN);
122 	if (ioctl(tapfd, SIOCSIFHWADDR, (void *)&ifr) == -1) {
123 		PMD_DRV_LOG(ERR, "SIOCSIFHWADDR failed: %s", strerror(errno));
124 		return -1;
125 	}
126 	return 0;
127 }
128 
129 static int
vhost_kernel_tap_set_offload(int fd,uint64_t features)130 vhost_kernel_tap_set_offload(int fd, uint64_t features)
131 {
132 	unsigned int offload = 0;
133 
134 	if (features & (1ULL << VIRTIO_NET_F_GUEST_CSUM)) {
135 		offload |= TUN_F_CSUM;
136 		if (features & (1ULL << VIRTIO_NET_F_GUEST_TSO4))
137 			offload |= TUN_F_TSO4;
138 		if (features & (1ULL << VIRTIO_NET_F_GUEST_TSO6))
139 			offload |= TUN_F_TSO6;
140 		if (features & ((1ULL << VIRTIO_NET_F_GUEST_TSO4) |
141 			(1ULL << VIRTIO_NET_F_GUEST_TSO6)) &&
142 			(features & (1ULL << VIRTIO_NET_F_GUEST_ECN)))
143 			offload |= TUN_F_TSO_ECN;
144 		if (features & (1ULL << VIRTIO_NET_F_GUEST_UFO))
145 			offload |= TUN_F_UFO;
146 	}
147 
148 	/* Check if our kernel supports TUNSETOFFLOAD */
149 	if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) {
150 		PMD_DRV_LOG(ERR, "Kernel doesn't support TUNSETOFFLOAD");
151 		return -ENOTSUP;
152 	}
153 
154 	if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
155 		offload &= ~TUN_F_UFO;
156 		if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) {
157 			PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s",
158 				strerror(errno));
159 			return -1;
160 		}
161 	}
162 
163 	return 0;
164 }
165 
166 int
vhost_kernel_tap_setup(int tapfd,int hdr_size,uint64_t features)167 vhost_kernel_tap_setup(int tapfd, int hdr_size, uint64_t features)
168 {
169 	int sndbuf = INT_MAX;
170 	int ret;
171 
172 	/* TODO:
173 	 * 1. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len
174 	 * 2. get number of memory regions from vhost module parameter
175 	 * max_mem_regions, supported in newer version linux kernel
176 	 */
177 	if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) {
178 		PMD_DRV_LOG(ERR, "TUNSETVNETHDRSZ failed: %s", strerror(errno));
179 		return -1;
180 	}
181 
182 	if (ioctl(tapfd, TUNSETSNDBUF, &sndbuf) < 0) {
183 		PMD_DRV_LOG(ERR, "TUNSETSNDBUF failed: %s", strerror(errno));
184 		return -1;
185 	}
186 
187 	ret = vhost_kernel_tap_set_offload(tapfd, features);
188 	if (ret == -ENOTSUP)
189 		ret = 0;
190 	return ret;
191 }
192