* [PATCH] pcap: Use clock_gettime() instead of gettimeofday()
@ 2024-03-12 19:01 Stefano Brivio
2024-03-14 2:11 ` David Gibson
0 siblings, 1 reply; 2+ messages in thread
From: Stefano Brivio @ 2024-03-12 19:01 UTC (permalink / raw)
To: passt-dev; +Cc: Jon Maloy
POSIX.1-2008 declared gettimeofday() as obsolete, but I'm a dinosaur.
Usually, C libraries translate that to the clock_gettime() system
call anyway, but this doesn't happen in Jon's environment, and,
there, seccomp happily kills pasta(1) when started with --pcap,
because we didn't add gettimeofday() to our seccomp profiles.
Use clock_gettime() instead.
Reported-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
---
pcap.c | 26 +++++++++++++-------------
util.h | 1 +
2 files changed, 14 insertions(+), 13 deletions(-)
diff --git a/pcap.c b/pcap.c
index a0f01ad..45bbfcd 100644
--- a/pcap.c
+++ b/pcap.c
@@ -72,17 +72,17 @@ struct pcap_pkthdr {
* @iov: IO vector containing frame (with L2 headers and tap headers)
* @iovcnt: Number of buffers (@iov entries) in frame
* @offset: Byte offset of the L2 headers within @iov
- * @tv: Timestamp
+ * @now: Timestamp
*
* Returns: 0 on success, -errno on error writing to the file
*/
static void pcap_frame(const struct iovec *iov, size_t iovcnt,
- size_t offset, const struct timeval *tv)
+ size_t offset, const struct timespec *now)
{
size_t len = iov_size(iov, iovcnt) - offset;
struct pcap_pkthdr h = {
- .tv_sec = tv->tv_sec,
- .tv_usec = tv->tv_usec,
+ .tv_sec = now->tv_sec,
+ .tv_usec = DIV_ROUND_CLOSEST(now->tv_nsec, 1000),
.caplen = len,
.len = len
};
@@ -103,13 +103,13 @@ static void pcap_frame(const struct iovec *iov, size_t iovcnt,
void pcap(const char *pkt, size_t len)
{
struct iovec iov = { (char *)pkt, len };
- struct timeval tv;
+ struct timespec now;
if (pcap_fd == -1)
return;
- gettimeofday(&tv, NULL);
- pcap_frame(&iov, 1, 0, &tv);
+ clock_gettime(CLOCK_REALTIME, &now);
+ pcap_frame(&iov, 1, 0, &now);
}
/**
@@ -122,16 +122,16 @@ void pcap(const char *pkt, size_t len)
void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
size_t offset)
{
- struct timeval tv;
+ struct timespec now;
unsigned int i;
if (pcap_fd == -1)
return;
- gettimeofday(&tv, NULL);
+ clock_gettime(CLOCK_REALTIME, &now);
for (i = 0; i < n; i++)
- pcap_frame(iov + i * frame_parts, frame_parts, offset, &tv);
+ pcap_frame(iov + i * frame_parts, frame_parts, offset, &now);
}
/*
@@ -145,13 +145,13 @@ void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
/* cppcheck-suppress unusedFunction */
void pcap_iov(const struct iovec *iov, size_t iovcnt)
{
- struct timeval tv;
+ struct timespec now;
if (pcap_fd == -1)
return;
- gettimeofday(&tv, NULL);
- pcap_frame(iov, iovcnt, 0, &tv);
+ clock_gettime(CLOCK_REALTIME, &now);
+ pcap_frame(iov, iovcnt, 0, &now);
}
/**
diff --git a/util.h b/util.h
index 25e54a7..48f3560 100644
--- a/util.h
+++ b/util.h
@@ -40,6 +40,7 @@
#endif
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+#define DIV_ROUND_CLOSEST(n, d) (((n) + (d) / 2) / (d))
#define ROUND_DOWN(x, y) ((x) & ~((y) - 1))
#define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1))
--
@@ -40,6 +40,7 @@
#endif
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+#define DIV_ROUND_CLOSEST(n, d) (((n) + (d) / 2) / (d))
#define ROUND_DOWN(x, y) ((x) & ~((y) - 1))
#define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1))
--
2.39.2
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [PATCH] pcap: Use clock_gettime() instead of gettimeofday()
2024-03-12 19:01 [PATCH] pcap: Use clock_gettime() instead of gettimeofday() Stefano Brivio
@ 2024-03-14 2:11 ` David Gibson
0 siblings, 0 replies; 2+ messages in thread
From: David Gibson @ 2024-03-14 2:11 UTC (permalink / raw)
To: Stefano Brivio; +Cc: passt-dev, Jon Maloy
[-- Attachment #1: Type: text/plain, Size: 3680 bytes --]
On Tue, Mar 12, 2024 at 08:01:20PM +0100, Stefano Brivio wrote:
> POSIX.1-2008 declared gettimeofday() as obsolete, but I'm a dinosaur.
>
> Usually, C libraries translate that to the clock_gettime() system
> call anyway, but this doesn't happen in Jon's environment, and,
> there, seccomp happily kills pasta(1) when started with --pcap,
> because we didn't add gettimeofday() to our seccomp profiles.
>
> Use clock_gettime() instead.
>
> Reported-by: Jon Maloy <jmaloy@redhat.com>
> Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> pcap.c | 26 +++++++++++++-------------
> util.h | 1 +
> 2 files changed, 14 insertions(+), 13 deletions(-)
>
> diff --git a/pcap.c b/pcap.c
> index a0f01ad..45bbfcd 100644
> --- a/pcap.c
> +++ b/pcap.c
> @@ -72,17 +72,17 @@ struct pcap_pkthdr {
> * @iov: IO vector containing frame (with L2 headers and tap headers)
> * @iovcnt: Number of buffers (@iov entries) in frame
> * @offset: Byte offset of the L2 headers within @iov
> - * @tv: Timestamp
> + * @now: Timestamp
> *
> * Returns: 0 on success, -errno on error writing to the file
> */
> static void pcap_frame(const struct iovec *iov, size_t iovcnt,
> - size_t offset, const struct timeval *tv)
> + size_t offset, const struct timespec *now)
> {
> size_t len = iov_size(iov, iovcnt) - offset;
> struct pcap_pkthdr h = {
> - .tv_sec = tv->tv_sec,
> - .tv_usec = tv->tv_usec,
> + .tv_sec = now->tv_sec,
> + .tv_usec = DIV_ROUND_CLOSEST(now->tv_nsec, 1000),
> .caplen = len,
> .len = len
> };
> @@ -103,13 +103,13 @@ static void pcap_frame(const struct iovec *iov, size_t iovcnt,
> void pcap(const char *pkt, size_t len)
> {
> struct iovec iov = { (char *)pkt, len };
> - struct timeval tv;
> + struct timespec now;
>
> if (pcap_fd == -1)
> return;
>
> - gettimeofday(&tv, NULL);
> - pcap_frame(&iov, 1, 0, &tv);
> + clock_gettime(CLOCK_REALTIME, &now);
> + pcap_frame(&iov, 1, 0, &now);
> }
>
> /**
> @@ -122,16 +122,16 @@ void pcap(const char *pkt, size_t len)
> void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
> size_t offset)
> {
> - struct timeval tv;
> + struct timespec now;
> unsigned int i;
>
> if (pcap_fd == -1)
> return;
>
> - gettimeofday(&tv, NULL);
> + clock_gettime(CLOCK_REALTIME, &now);
>
> for (i = 0; i < n; i++)
> - pcap_frame(iov + i * frame_parts, frame_parts, offset, &tv);
> + pcap_frame(iov + i * frame_parts, frame_parts, offset, &now);
> }
>
> /*
> @@ -145,13 +145,13 @@ void pcap_multiple(const struct iovec *iov, size_t frame_parts, unsigned int n,
> /* cppcheck-suppress unusedFunction */
> void pcap_iov(const struct iovec *iov, size_t iovcnt)
> {
> - struct timeval tv;
> + struct timespec now;
>
> if (pcap_fd == -1)
> return;
>
> - gettimeofday(&tv, NULL);
> - pcap_frame(iov, iovcnt, 0, &tv);
> + clock_gettime(CLOCK_REALTIME, &now);
> + pcap_frame(iov, iovcnt, 0, &now);
> }
>
> /**
> diff --git a/util.h b/util.h
> index 25e54a7..48f3560 100644
> --- a/util.h
> +++ b/util.h
> @@ -40,6 +40,7 @@
> #endif
>
> #define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
> +#define DIV_ROUND_CLOSEST(n, d) (((n) + (d) / 2) / (d))
> #define ROUND_DOWN(x, y) ((x) & ~((y) - 1))
> #define ROUND_UP(x, y) (((x) + (y) - 1) & ~((y) - 1))
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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2024-03-12 19:01 [PATCH] pcap: Use clock_gettime() instead of gettimeofday() Stefano Brivio
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