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 <linux/if.h> 22 #include <linux/if_ether.h> 23 #include <netinet/in.h> 24 #include <poll.h> 25 #include <sys/socket.h> 26 27 #include <cstring> 28 #include <iterator> 29 30 namespace ncsi 31 { 32 init()33 int SockIO::init() 34 { 35 RETURN_IF_ERROR(sockfd_ = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL)), 36 "ncsi::SockIO::init() failed"); 37 return 0; 38 } 39 bind_to_iface(const net::IFaceBase & iface)40 int SockIO::bind_to_iface(const net::IFaceBase& iface) 41 { 42 struct packet_mreq mreq = {}; 43 RETURN_IF_ERROR(mreq.mr_ifindex = iface.get_index(), 44 "ncsi::SockIO::bind_to_iface get_index"); 45 mreq.mr_type = PACKET_MR_PROMISC; 46 RETURN_IF_ERROR(setsockopt(sockfd_, SOL_PACKET, PACKET_ADD_MEMBERSHIP, 47 &mreq, sizeof(mreq)), 48 "ncsi::SockIO::bind_to_iface setsockopt failed"); 49 50 RETURN_IF_ERROR(iface.bind_sock(sockfd_), 51 "ncsi::SockIO::bind_to_iface failed"); 52 53 return 0; 54 } 55 56 /** 57 * Drops VLAN tagged packets from a socket 58 * 59 * ld vlant 60 * jneq #0, drop 61 * ld proto 62 * jneq #0x88f8, drop 63 * ret #-1 64 * drop: ret #0 65 */ 66 struct sock_filter vlan_remove_code[] = { 67 {0x20, 0, 0, 0xfffff02c}, {0x15, 0, 3, 0x00000000}, 68 {0x20, 0, 0, 0xfffff000}, {0x15, 0, 1, 0x000088f8}, 69 {0x6, 0, 0, 0xffffffff}, {0x6, 0, 0, 0x00000000}}; 70 71 struct sock_fprog vlan_remove_bpf = { 72 std::size(vlan_remove_code), 73 vlan_remove_code, 74 }; 75 filter_vlans()76 int SockIO::filter_vlans() 77 { 78 return setsockopt(sockfd_, SOL_SOCKET, SO_ATTACH_FILTER, &vlan_remove_bpf, 79 sizeof(vlan_remove_bpf)); 80 } 81 recv(void * buf,size_t maxlen)82 int SockIO::recv(void* buf, size_t maxlen) 83 { 84 struct pollfd sock_pollfd{sockfd_, POLLIN | POLLPRI, 0}; 85 86 int ret = poll(&sock_pollfd, 1, kpoll_timeout_); 87 if (ret > 0) 88 { 89 return ::recv(sockfd_, buf, maxlen, 0); 90 } 91 92 return ret; 93 } 94 95 } // namespace ncsi 96