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 static int 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 if (offload != 0) { 41 /* Check if our kernel supports TUNSETOFFLOAD */ 42 if (ioctl(fd, TUNSETOFFLOAD, 0) != 0 && errno == EINVAL) { 43 PMD_DRV_LOG(ERR, "Kernel does't support TUNSETOFFLOAD\n"); 44 return -ENOTSUP; 45 } 46 47 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) { 48 offload &= ~TUN_F_UFO; 49 if (ioctl(fd, TUNSETOFFLOAD, offload) != 0) { 50 PMD_DRV_LOG(ERR, "TUNSETOFFLOAD ioctl() failed: %s\n", 51 strerror(errno)); 52 return -1; 53 } 54 } 55 } 56 57 return 0; 58 } 59 60 int 61 vhost_kernel_open_tap(char **p_ifname, int hdr_size, int req_mq, 62 const char *mac, uint64_t features) 63 { 64 unsigned int tap_features; 65 int sndbuf = INT_MAX; 66 struct ifreq ifr; 67 int tapfd; 68 69 /* TODO: 70 * 1. verify we can get/set vnet_hdr_len, tap_probe_vnet_hdr_len 71 * 2. get number of memory regions from vhost module parameter 72 * max_mem_regions, supported in newer version linux kernel 73 */ 74 tapfd = open(PATH_NET_TUN, O_RDWR); 75 if (tapfd < 0) { 76 PMD_DRV_LOG(ERR, "fail to open %s: %s", 77 PATH_NET_TUN, strerror(errno)); 78 return -1; 79 } 80 81 /* Construct ifr */ 82 memset(&ifr, 0, sizeof(ifr)); 83 ifr.ifr_flags = IFF_TAP | IFF_NO_PI; 84 85 if (ioctl(tapfd, TUNGETFEATURES, &tap_features) == -1) { 86 PMD_DRV_LOG(ERR, "TUNGETFEATURES failed: %s", strerror(errno)); 87 goto error; 88 } 89 if (tap_features & IFF_ONE_QUEUE) 90 ifr.ifr_flags |= IFF_ONE_QUEUE; 91 92 /* Let tap instead of vhost-net handle vnet header, as the latter does 93 * not support offloading. And in this case, we should not set feature 94 * bit VHOST_NET_F_VIRTIO_NET_HDR. 95 */ 96 if (tap_features & IFF_VNET_HDR) { 97 ifr.ifr_flags |= IFF_VNET_HDR; 98 } else { 99 PMD_DRV_LOG(ERR, "TAP does not support IFF_VNET_HDR"); 100 goto error; 101 } 102 103 if (req_mq) 104 ifr.ifr_flags |= IFF_MULTI_QUEUE; 105 106 if (*p_ifname) 107 strncpy(ifr.ifr_name, *p_ifname, IFNAMSIZ - 1); 108 else 109 strncpy(ifr.ifr_name, "tap%d", IFNAMSIZ - 1); 110 if (ioctl(tapfd, TUNSETIFF, (void *)&ifr) == -1) { 111 PMD_DRV_LOG(ERR, "TUNSETIFF failed: %s", strerror(errno)); 112 goto error; 113 } 114 115 fcntl(tapfd, F_SETFL, O_NONBLOCK); 116 117 if (ioctl(tapfd, TUNSETVNETHDRSZ, &hdr_size) < 0) { 118 PMD_DRV_LOG(ERR, "TUNSETVNETHDRSZ failed: %s", strerror(errno)); 119 goto error; 120 } 121 122 if (ioctl(tapfd, TUNSETSNDBUF, &sndbuf) < 0) { 123 PMD_DRV_LOG(ERR, "TUNSETSNDBUF failed: %s", strerror(errno)); 124 goto error; 125 } 126 127 vhost_kernel_tap_set_offload(tapfd, features); 128 129 memset(&ifr, 0, sizeof(ifr)); 130 ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER; 131 memcpy(ifr.ifr_hwaddr.sa_data, mac, ETHER_ADDR_LEN); 132 if (ioctl(tapfd, SIOCSIFHWADDR, (void *)&ifr) == -1) { 133 PMD_DRV_LOG(ERR, "SIOCSIFHWADDR failed: %s", strerror(errno)); 134 goto error; 135 } 136 137 if (!(*p_ifname)) 138 *p_ifname = strdup(ifr.ifr_name); 139 140 return tapfd; 141 error: 142 close(tapfd); 143 return -1; 144 } 145