laforge has uploaded this change for review. (
https://gerrit.osmocom.org/c/titan.TestPorts.AF_PACKET/+/22539 )
Change subject: add module parameter "sleep_on_enobufs" to work around -ENOBUFS
......................................................................
add module parameter "sleep_on_enobufs" to work around -ENOBUFS
AF_PACKET sockets have these incredibly useful semantics in where
for both non-blocking and blocking I/O, they will tell you the
socket is rwite-able, but then still return -1 and sett errno=ENOBUFS
if the current socket buffer / transmit queue is full.
All we can do is usleep and retry. The new module parameter, if set
to non-zero, determines the number of microseconds we shall sleep before
any retry. If set to zero, the existing behavior is preserved:
TTCN_error().
Related: SYS#5343
Change-Id: I1608403d94a10ae52c7e1de0f1b02687b048c01e
---
M src/AF_PACKET_PT.cc
M src/AF_PACKET_PT.hh
2 files changed, 17 insertions(+), 5 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/titan.TestPorts.AF_PACKET
refs/changes/39/22539/1
diff --git a/src/AF_PACKET_PT.cc b/src/AF_PACKET_PT.cc
index aa2def6..935f47c 100644
--- a/src/AF_PACKET_PT.cc
+++ b/src/AF_PACKET_PT.cc
@@ -108,6 +108,8 @@
mNetdev_name = NULL;
}
mNetdev_name = strdup(parameter_value);
+ } else if (!strcmp(parameter_name, "sleep_on_enobufs")) {
+ mSleepUsOnEnobufs = atoi(parameter_value);
} else
TTCN_error("Unsupported test port parameter `%s'.",
parameter_name);
}
@@ -204,13 +206,22 @@
void AF__PACKET__PT_PROVIDER::outgoing_send(const AF__PACKET__Unitdata&
send_par)
{
- int rc;
-
assert(mSocket >= 0);
- rc = write(mSocket, send_par.data(), send_par.data().lengthof());
- if (rc < send_par.data().lengthof())
- TTCN_error("Short write on AF_PACKET socket: %s",
strerror(errno));
+ while (true) {
+ int rc = write(mSocket, send_par.data(),
send_par.data().lengthof());
+ if (rc == send_par.data().lengthof())
+ break;
+ if (mSleepUsOnEnobufs && rc == -1 && errno == -ENOBUFS) {
+ /* This is fscking insane. Even select() would tell us
the FD
+ * is write-able, but then we still get -ENOBUFS. The
only way
+ * to do this os to sleep. */
+ usleep(mSleepUsOnEnobufs);
+ } else if (rc < send_par.data().lengthof()) {
+ TTCN_error("Short write on AF_PACKET socket: %s",
strerror(errno));
+ break;
+ }
+ }
}
diff --git a/src/AF_PACKET_PT.hh b/src/AF_PACKET_PT.hh
index 7f8f6b5..ab3e8c6 100644
--- a/src/AF_PACKET_PT.hh
+++ b/src/AF_PACKET_PT.hh
@@ -50,6 +50,7 @@
private:
char *mNetdev_name; /* name of the network interface */
+ bool mSleepUsOnEnobufs; /* how many us to sleep on ENOBUFS */
int mIfindex; /* interface index of the network
device */
int mSocket; /* socket/file descriptor of the
AF_PACKET socket */
uint8_t mRxBuf[2048]; /* read buffer */
--
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Gerrit-Project: titan.TestPorts.AF_PACKET
Gerrit-Branch: master
Gerrit-Change-Id: I1608403d94a10ae52c7e1de0f1b02687b048c01e
Gerrit-Change-Number: 22539
Gerrit-PatchSet: 1
Gerrit-Owner: laforge <lafo...@osmocom.org>
Gerrit-MessageType: newchange
