1 // Copyright 2021 Google LLC 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 #include "ncsi_sockio.h" 16 17 #include "common_defs.h" 18 #include "net_iface.h" 19 20 #include <linux/filter.h> 21 #include <netinet/in.h> 22 #include <poll.h> 23 #include <sys/socket.h> 24 #include <sys/types.h> 25 26 #include <cstdio> 27 #include <cstring> 28 29 namespace ncsi 30 { 31 32 int SockIO::init() 33 { 34 RETURN_IF_ERROR(sockfd_ = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL)), 35 "ncsi::SockIO::init() failed"); 36 return 0; 37 } 38 39 int SockIO::bind_to_iface(const net::IFaceBase& iface) 40 { 41 iface.set_sock_flags(sockfd_, IFF_PROMISC); 42 43 std::memset(&sock_addr_, 0, sizeof(sock_addr_)); 44 45 sock_addr_.sll_family = AF_PACKET; 46 sock_addr_.sll_protocol = htons(ETH_P_ALL); 47 48 RETURN_IF_ERROR(iface.bind_sock(sockfd_, &sock_addr_), 49 "ncsi::SockIO::bind_to_iface failed"); 50 51 return 0; 52 } 53 54 /** 55 * Drops VLAN tagged packets from a socket 56 * 57 * ld vlant 58 * jneq #0, drop 59 * ld proto 60 * jneq #0x88f8, drop 61 * ret #-1 62 * drop: ret #0 63 */ 64 struct sock_filter vlan_remove_code[] = { 65 {0x20, 0, 0, 0xfffff02c}, {0x15, 0, 3, 0x00000000}, 66 {0x20, 0, 0, 0xfffff000}, {0x15, 0, 1, 0x000088f8}, 67 {0x6, 0, 0, 0xffffffff}, {0x6, 0, 0, 0x00000000}}; 68 69 struct sock_fprog vlan_remove_bpf = { 70 std::size(vlan_remove_code), 71 vlan_remove_code, 72 }; 73 74 int SockIO::filter_vlans() 75 { 76 return setsockopt(sockfd_, SOL_SOCKET, SO_ATTACH_FILTER, &vlan_remove_bpf, 77 sizeof(vlan_remove_bpf)); 78 } 79 80 int SockIO::recv(void* buf, size_t maxlen) 81 { 82 struct pollfd sock_pollfd 83 { 84 sockfd_, POLLIN | POLLPRI, 0 85 }; 86 87 int ret = poll(&sock_pollfd, 1, kpoll_timeout_); 88 if (ret > 0) 89 { 90 return ::recv(sockfd_, buf, maxlen, 0); 91 } 92 93 return ret; 94 } 95 96 } // namespace ncsi 97