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