1 // Copyright 2022 gRPC authors.
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 <grpc/support/port_platform.h>
16 
17 #include "src/core/lib/event_engine/posix_engine/internal_errqueue.h"
18 
19 #include <string>
20 
21 #include <grpc/support/log.h>
22 
23 #include "src/core/lib/iomgr/port.h"
24 
25 #ifdef GRPC_POSIX_SOCKET_TCP
26 
27 #include <errno.h>
28 #include <netinet/in.h>
29 #include <stdlib.h>
30 #include <string.h>
31 #include <sys/utsname.h>
32 
33 #include <cstddef>
34 
35 #include "src/core/lib/gprpp/strerror.h"
36 
37 namespace grpc_event_engine {
38 namespace experimental {
39 
40 #ifdef GRPC_LINUX_ERRQUEUE
GetSocketTcpInfo(struct tcp_info * info,int fd)41 int GetSocketTcpInfo(struct tcp_info* info, int fd) {
42   memset(info, 0, sizeof(*info));
43   info->length = offsetof(tcp_info, length);
44   return getsockopt(fd, IPPROTO_TCP, TCP_INFO, info, &(info->length));
45 }
46 #endif
47 
KernelSupportsErrqueue()48 bool KernelSupportsErrqueue() {
49   static const bool errqueue_supported = []() {
50 #ifdef GRPC_LINUX_ERRQUEUE
51     // Both-compile time and run-time linux kernel versions should be at
52     // least 4.0.0
53     struct utsname buffer;
54     if (uname(&buffer) != 0) {
55       gpr_log(GPR_ERROR, "uname: %s", grpc_core::StrError(errno).c_str());
56       return false;
57     }
58     char* release = buffer.release;
59     if (release == nullptr) {
60       return false;
61     }
62 
63     if (strtol(release, nullptr, 10) >= 4) {
64       return true;
65     } else {
66       gpr_log(GPR_DEBUG, "ERRQUEUE support not enabled");
67     }
68 #endif  // GRPC_LINUX_ERRQUEUE
69     return false;
70   }();
71   return errqueue_supported;
72 }
73 
74 }  // namespace experimental
75 }  // namespace grpc_event_engine
76 
77 #endif  // GRPC_POSIX_SOCKET_TCP
78