From: David Gibson <david@gibson.dropbear.id.au>
To: Stefano Brivio <sbrivio@redhat.com>, passt-dev@passt.top
Cc: David Gibson <david@gibson.dropbear.id.au>
Subject: [PATCH v3 01/18] pcap: Introduce pcap_frame() helper
Date: Fri, 6 Jan 2023 11:43:05 +1100 [thread overview]
Message-ID: <20230106004322.985665-2-david@gibson.dropbear.id.au> (raw)
In-Reply-To: <20230106004322.985665-1-david@gibson.dropbear.id.au>
pcap(), pcapm() and pcapmm() duplicate some code, for the actual writing
to the capture file. The purpose of pcapm() and pcapmm() not calling
pcap() seems to be to avoid repeatedly calling gettimeofday() and to avoid
printing errors for every packet in a batch if there's a problem. We can
accomplish that while still sharing code by adding a new helper which
takes the packet timestamp as a parameter.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
---
pcap.c | 76 +++++++++++++++++++++++++++++-----------------------------
1 file changed, 38 insertions(+), 38 deletions(-)
diff --git a/pcap.c b/pcap.c
index 836688d..0c6dc89 100644
--- a/pcap.c
+++ b/pcap.c
@@ -65,6 +65,28 @@ struct pcap_pkthdr {
uint32_t len;
};
+/**
+ * pcap_frame() - Capture a single frame to pcap file with given timestamp
+ * @pkt: Pointer to data buffer, including L2 headers
+ * @len: L2 packet length
+ * @tv: Timestamp
+ *
+ * Returns: 0 on success, -errno on error writing to the file
+ */
+static int pcap_frame(const char *pkt, size_t len, const struct timeval *tv)
+{
+ struct pcap_pkthdr h;
+
+ h.tv_sec = tv->tv_sec;
+ h.tv_usec = tv->tv_usec;
+ h.caplen = h.len = len;
+
+ if (write(pcap_fd, &h, sizeof(h)) < 0 || write(pcap_fd, pkt, len) < 0)
+ return -errno;
+
+ return 0;
+}
+
/**
* pcap() - Capture a single frame to pcap file
* @pkt: Pointer to data buffer, including L2 headers
@@ -72,18 +94,13 @@ struct pcap_pkthdr {
*/
void pcap(const char *pkt, size_t len)
{
- struct pcap_pkthdr h;
struct timeval tv;
if (pcap_fd == -1)
return;
gettimeofday(&tv, NULL);
- h.tv_sec = tv.tv_sec;
- h.tv_usec = tv.tv_usec;
- h.caplen = h.len = len;
-
- if (write(pcap_fd, &h, sizeof(h)) < 0 || write(pcap_fd, pkt, len) < 0)
+ if (pcap_frame(pkt, len, &tv) != 0)
debug("Cannot log packet, length %lu", len);
}
@@ -93,8 +110,6 @@ void pcap(const char *pkt, size_t len)
*/
void pcapm(const struct msghdr *mh)
{
- struct pcap_pkthdr h;
- struct iovec *iov;
struct timeval tv;
unsigned int i;
@@ -102,24 +117,17 @@ void pcapm(const struct msghdr *mh)
return;
gettimeofday(&tv, NULL);
- h.tv_sec = tv.tv_sec;
- h.tv_usec = tv.tv_usec;
for (i = 0; i < mh->msg_iovlen; i++) {
- iov = &mh->msg_iov[i];
+ const struct iovec *iov = &mh->msg_iov[i];
- h.caplen = h.len = iov->iov_len - 4;
-
- if (write(pcap_fd, &h, sizeof(h)) < 0)
- goto fail;
- if (write(pcap_fd, (char *)iov->iov_base + 4,
- iov->iov_len - 4) < 0)
- goto fail;
+ if (pcap_frame((char *)iov->iov_base + 4,
+ iov->iov_len - 4, &tv) != 0) {
+ debug("Cannot log packet, length %lu",
+ iov->iov_len - 4);
+ return;
+ }
}
-
- return;
-fail:
- debug("Cannot log packet, length %lu", iov->iov_len - 4);
}
/**
@@ -128,8 +136,6 @@ fail:
*/
void pcapmm(const struct mmsghdr *mmh, unsigned int vlen)
{
- struct pcap_pkthdr h;
- struct iovec *iov;
struct timeval tv;
unsigned int i, j;
@@ -137,27 +143,21 @@ void pcapmm(const struct mmsghdr *mmh, unsigned int vlen)
return;
gettimeofday(&tv, NULL);
- h.tv_sec = tv.tv_sec;
- h.tv_usec = tv.tv_usec;
for (i = 0; i < vlen; i++) {
const struct msghdr *mh = &mmh[i].msg_hdr;
for (j = 0; j < mh->msg_iovlen; j++) {
- iov = &mh->msg_iov[j];
-
- h.caplen = h.len = iov->iov_len - 4;
-
- if (write(pcap_fd, &h, sizeof(h)) < 0)
- goto fail;
- if (write(pcap_fd, (char *)iov->iov_base + 4,
- iov->iov_len - 4) < 0)
- goto fail;
+ const struct iovec *iov = &mh->msg_iov[j];
+
+ if (pcap_frame((char *)iov->iov_base + 4,
+ iov->iov_len - 4, &tv) != 0) {
+ debug("Cannot log packet, length %lu",
+ iov->iov_len - 4);
+ return;
+ }
}
}
- return;
-fail:
- debug("Cannot log packet, length %lu", iov->iov_len - 4);
}
/**
--
@@ -65,6 +65,28 @@ struct pcap_pkthdr {
uint32_t len;
};
+/**
+ * pcap_frame() - Capture a single frame to pcap file with given timestamp
+ * @pkt: Pointer to data buffer, including L2 headers
+ * @len: L2 packet length
+ * @tv: Timestamp
+ *
+ * Returns: 0 on success, -errno on error writing to the file
+ */
+static int pcap_frame(const char *pkt, size_t len, const struct timeval *tv)
+{
+ struct pcap_pkthdr h;
+
+ h.tv_sec = tv->tv_sec;
+ h.tv_usec = tv->tv_usec;
+ h.caplen = h.len = len;
+
+ if (write(pcap_fd, &h, sizeof(h)) < 0 || write(pcap_fd, pkt, len) < 0)
+ return -errno;
+
+ return 0;
+}
+
/**
* pcap() - Capture a single frame to pcap file
* @pkt: Pointer to data buffer, including L2 headers
@@ -72,18 +94,13 @@ struct pcap_pkthdr {
*/
void pcap(const char *pkt, size_t len)
{
- struct pcap_pkthdr h;
struct timeval tv;
if (pcap_fd == -1)
return;
gettimeofday(&tv, NULL);
- h.tv_sec = tv.tv_sec;
- h.tv_usec = tv.tv_usec;
- h.caplen = h.len = len;
-
- if (write(pcap_fd, &h, sizeof(h)) < 0 || write(pcap_fd, pkt, len) < 0)
+ if (pcap_frame(pkt, len, &tv) != 0)
debug("Cannot log packet, length %lu", len);
}
@@ -93,8 +110,6 @@ void pcap(const char *pkt, size_t len)
*/
void pcapm(const struct msghdr *mh)
{
- struct pcap_pkthdr h;
- struct iovec *iov;
struct timeval tv;
unsigned int i;
@@ -102,24 +117,17 @@ void pcapm(const struct msghdr *mh)
return;
gettimeofday(&tv, NULL);
- h.tv_sec = tv.tv_sec;
- h.tv_usec = tv.tv_usec;
for (i = 0; i < mh->msg_iovlen; i++) {
- iov = &mh->msg_iov[i];
+ const struct iovec *iov = &mh->msg_iov[i];
- h.caplen = h.len = iov->iov_len - 4;
-
- if (write(pcap_fd, &h, sizeof(h)) < 0)
- goto fail;
- if (write(pcap_fd, (char *)iov->iov_base + 4,
- iov->iov_len - 4) < 0)
- goto fail;
+ if (pcap_frame((char *)iov->iov_base + 4,
+ iov->iov_len - 4, &tv) != 0) {
+ debug("Cannot log packet, length %lu",
+ iov->iov_len - 4);
+ return;
+ }
}
-
- return;
-fail:
- debug("Cannot log packet, length %lu", iov->iov_len - 4);
}
/**
@@ -128,8 +136,6 @@ fail:
*/
void pcapmm(const struct mmsghdr *mmh, unsigned int vlen)
{
- struct pcap_pkthdr h;
- struct iovec *iov;
struct timeval tv;
unsigned int i, j;
@@ -137,27 +143,21 @@ void pcapmm(const struct mmsghdr *mmh, unsigned int vlen)
return;
gettimeofday(&tv, NULL);
- h.tv_sec = tv.tv_sec;
- h.tv_usec = tv.tv_usec;
for (i = 0; i < vlen; i++) {
const struct msghdr *mh = &mmh[i].msg_hdr;
for (j = 0; j < mh->msg_iovlen; j++) {
- iov = &mh->msg_iov[j];
-
- h.caplen = h.len = iov->iov_len - 4;
-
- if (write(pcap_fd, &h, sizeof(h)) < 0)
- goto fail;
- if (write(pcap_fd, (char *)iov->iov_base + 4,
- iov->iov_len - 4) < 0)
- goto fail;
+ const struct iovec *iov = &mh->msg_iov[j];
+
+ if (pcap_frame((char *)iov->iov_base + 4,
+ iov->iov_len - 4, &tv) != 0) {
+ debug("Cannot log packet, length %lu",
+ iov->iov_len - 4);
+ return;
+ }
}
}
- return;
-fail:
- debug("Cannot log packet, length %lu", iov->iov_len - 4);
}
/**
--
2.39.0
next prev parent reply other threads:[~2023-01-06 0:43 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-01-06 0:43 [PATCH v3 00/18] RFC: Unify and simplify tap send path David Gibson
2023-01-06 0:43 ` David Gibson [this message]
2023-01-06 0:43 ` [PATCH v3 02/18] pcap: Replace pcapm() with pcap_multiple() David Gibson
2023-01-06 0:43 ` [PATCH v3 03/18] tcp: Combine two parts of passt tap send path together David Gibson
2023-01-06 0:43 ` [PATCH v3 04/18] tcp: Don't compute total bytes in a message until we need it David Gibson
2023-01-06 0:43 ` [PATCH v3 05/18] tcp: Improve interface to tcp_l2_buf_flush() David Gibson
2023-01-06 0:43 ` [PATCH v3 06/18] tcp: Combine two parts of pasta tap send path together David Gibson
2023-02-13 1:13 ` Stefano Brivio
2023-01-06 0:43 ` [PATCH v3 07/18] tap, tcp: Move tap send path to tap.c David Gibson
2023-01-06 0:43 ` [PATCH v3 08/18] util: Introduce hton*_constant() in place of #ifdefs David Gibson
2023-01-06 0:43 ` [PATCH v3 09/18] tcp, udp: Use named field initializers in iov_init functions David Gibson
2023-01-06 0:43 ` [PATCH v3 10/18] util: Parameterize ethernet header initializer macro David Gibson
2023-01-06 0:43 ` [PATCH v3 11/18] tcp: Remove redundant and incorrect initialization from *_iov_init() David Gibson
2023-01-06 0:43 ` [PATCH v3 12/18] tcp: Consolidate calculation of total frame size David Gibson
2023-01-06 0:43 ` [PATCH v3 13/18] tap: Add "tap headers" abstraction David Gibson
2023-01-06 0:43 ` [PATCH v3 14/18] tcp: Use abstracted tap header David Gibson
2023-01-06 0:43 ` [PATCH v3 15/18] tap: Use different io vector bases depending on tap type David Gibson
2023-01-06 0:43 ` [PATCH v3 16/18] udp: Use abstracted tap header David Gibson
2023-01-06 0:43 ` [PATCH v3 17/18] tap: Improve handling of partial frame sends David Gibson
2023-01-06 0:43 ` [PATCH v3 18/18] udp: Use tap_send_frames() David Gibson
2023-01-24 21:20 ` [PATCH v3 00/18] RFC: Unify and simplify tap send path Stefano Brivio
2023-01-25 3:13 ` David Gibson
2023-01-25 23:21 ` Stefano Brivio
2023-02-13 1:14 ` Stefano Brivio
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