tools/testing/selftests/net/timestamping.c
Source file repositories/reference/linux-study-clean/tools/testing/selftests/net/timestamping.c
File Facts
- System
- Linux kernel
- Corpus path
tools/testing/selftests/net/timestamping.c- Extension
.c- Size
- 16004 bytes
- Lines
- 552
- Domain
- Support Tooling And Documentation
- Bucket
- tools
- Inferred role
- Support Tooling And Documentation: implementation source
- Status
- source implementation candidate
Why This File Exists
Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.
- Touches IRQ or DMA behavior; this matters for the representative real-device path.
- Defines or uses C structs; map object ownership, embedded links, reference counts, and lock ownership.
Dependency Surface
stdio.hstdlib.herrno.hstring.hsys/time.hsys/socket.hsys/select.hsys/ioctl.harpa/inet.hnet/if.hasm/types.hlinux/net_tstamp.hlinux/errqueue.hlinux/sockios.h
Detected Declarations
function Copyrightfunction bailfunction sendpacketfunction printpacketfunction recvpacketfunction main
Annotated Snippet
switch (cmsg->cmsg_level) {
case SOL_SOCKET:
printf("SOL_SOCKET ");
switch (cmsg->cmsg_type) {
case SO_TIMESTAMP: {
struct timeval *stamp =
(struct timeval *)CMSG_DATA(cmsg);
printf("SO_TIMESTAMP %ld.%06ld",
(long)stamp->tv_sec,
(long)stamp->tv_usec);
break;
}
case SO_TIMESTAMPNS: {
struct timespec *stamp =
(struct timespec *)CMSG_DATA(cmsg);
printf("SO_TIMESTAMPNS %ld.%09ld",
(long)stamp->tv_sec,
(long)stamp->tv_nsec);
break;
}
case SO_TIMESTAMPING: {
struct timespec *stamp =
(struct timespec *)CMSG_DATA(cmsg);
printf("SO_TIMESTAMPING ");
printf("SW %ld.%09ld ",
(long)stamp->tv_sec,
(long)stamp->tv_nsec);
stamp++;
/* skip deprecated HW transformed */
stamp++;
printf("HW raw %ld.%09ld",
(long)stamp->tv_sec,
(long)stamp->tv_nsec);
break;
}
default:
printf("type %d", cmsg->cmsg_type);
break;
}
break;
case IPPROTO_IP:
printf("IPPROTO_IP ");
switch (cmsg->cmsg_type) {
case IP_RECVERR: {
struct sock_extended_err *err =
(struct sock_extended_err *)CMSG_DATA(cmsg);
printf("IP_RECVERR ee_errno '%s' ee_origin %d => %s",
strerror(err->ee_errno),
err->ee_origin,
#ifdef SO_EE_ORIGIN_TIMESTAMPING
err->ee_origin == SO_EE_ORIGIN_TIMESTAMPING ?
"bounced packet" : "unexpected origin"
#else
"probably SO_EE_ORIGIN_TIMESTAMPING"
#endif
);
if (res < sync_len)
printf(" => truncated data?!");
else if (!memcmp(sync_p, data + res - sync_len, sync_len))
printf(" => GOT OUR DATA BACK (HURRAY!)");
break;
}
case IP_PKTINFO: {
struct in_pktinfo *pktinfo =
(struct in_pktinfo *)CMSG_DATA(cmsg);
printf("IP_PKTINFO interface index %u",
pktinfo->ipi_ifindex);
break;
}
default:
printf("type %d", cmsg->cmsg_type);
break;
}
break;
default:
printf("level %d type %d",
cmsg->cmsg_level,
cmsg->cmsg_type);
break;
}
printf("\n");
}
if (siocgstamp) {
if (ioctl(sock, SIOCGSTAMP, &tv))
printf(" %s: %s\n", "SIOCGSTAMP", strerror(errno));
else
printf("SIOCGSTAMP %ld.%06ld\n",
(long)tv.tv_sec,
(long)tv.tv_usec);
Annotation
- Immediate include surface: `stdio.h`, `stdlib.h`, `errno.h`, `string.h`, `sys/time.h`, `sys/socket.h`, `sys/select.h`, `sys/ioctl.h`.
- Detected declarations: `function Copyright`, `function bail`, `function sendpacket`, `function printpacket`, `function recvpacket`, `function main`.
- Atlas domain: Support Tooling And Documentation / tools.
- Implementation status: source implementation candidate.
- IRQ or DMA behavior appears here, which is relevant to the selected PCIe/NVMe device path.
Implementation Notes
- This generated page is the file-by-file coverage layer; curated subsystem chapters should link here when they synthesize a multi-file control flow.
- Core OS pages should be promoted from atlas-only to deep-reviewed when they explain data structures, invariants, locking, lifecycle, and C implementation snippets.
- Driver-family pages are intentionally pattern-oriented unless they are part of the selected PCIe/NVMe representative device path.