xref: /openbmc/google-misc/subprojects/ncsid/src/ncsi_sockio.cpp (revision 7c15db6f4dcd1da68967ca2a463ef890d4521f56)
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