Introduce a new function pcap_iov() to capture packet desribed by an IO
vector.
Update pcap_frame() to manage iovcnt > 1.
Signed-off-by: Laurent Vivier <lvivier(a)redhat.com>
Reviewed-by: David Gibson <david(a)gibson.dropbear.id.au>
---
Notes:
v5:
- add David's R-b
v4:
- use pcap_frame()
v3:
- update rationale
- update comment
- use strerror(errno)
- use size_t for io vector length
v2:
- introduce pcap_header(), a common helper to write
packet header
- use writev() rather than write() in a loop
- add functions comment
pcap.c | 26 ++++++++++++++++++++++----
pcap.h | 1 +
2 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/pcap.c b/pcap.c
index a4057b5f9c6a..372f02045262 100644
--- a/pcap.c
+++ b/pcap.c
@@ -32,6 +32,7 @@
#include "passt.h"
#include "log.h"
#include "pcap.h"
+#include "iov.h"
#define PCAP_VERSION_MINOR 4
@@ -78,7 +79,7 @@ struct pcap_pkthdr {
static void pcap_frame(const struct iovec *iov, size_t iovcnt,
size_t offset, const struct timeval *tv)
{
- size_t len = iov->iov_len - offset;
+ size_t len = iov_size(iov, iovcnt) - offset;
struct pcap_pkthdr h = {
.tv_sec = tv->tv_sec,
.tv_usec = tv->tv_usec,
@@ -87,10 +88,8 @@ static void pcap_frame(const struct iovec *iov, size_t iovcnt,
};
struct iovec hiov = { &h, sizeof(h) };
- (void)iovcnt;
-
if (write_remainder(pcap_fd, &hiov, 1, 0) < 0 ||
- write_remainder(pcap_fd, iov, 1, offset) < 0) {
+ write_remainder(pcap_fd, iov, iovcnt, offset) < 0) {
debug("Cannot log packet, length %zu: %s",
len, strerror(errno));
}
@@ -135,6 +134,25 @@ void pcap_multiple(const struct iovec *iov, size_t frame_parts,
unsigned int n,
pcap_frame(iov + i * frame_parts, frame_parts, offset, &tv);
}
+/*
+ * pcap_iov - Write packet data described by an I/O vector
+ * to a pcap file descriptor.
+ *
+ * @iov: Pointer to the array of struct iovec describing the I/O vector
+ * containing packet data to write, including L2 header
+ * @iovcnt: Number of buffers (@iov entries)
+ */
+void pcap_iov(const struct iovec *iov, size_t iovcnt)
+{
+ struct timeval tv;
+
+ if (pcap_fd == -1)
+ return;
+
+ gettimeofday(&tv, NULL);
+ pcap_frame(iov, iovcnt, 0, &tv);
+}
+
/**
* pcap_init() - Initialise pcap file
* @c: Execution context
diff --git a/pcap.h b/pcap.h
index 85fc58e57572..b1c4c909c109 100644
--- a/pcap.h
+++ b/pcap.h
@@ -9,6 +9,7 @@
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);
+void pcap_iov(const struct iovec *iov, size_t n);
void pcap_init(struct ctx *c);
#endif /* PCAP_H */
--
2.42.0