[SCM] Samba Shared Repository - branch v4-19-test updated
Jule Anger
janger at samba.org
Tue Aug 29 09:35:01 UTC 2023
The branch, v4-19-test has been updated
via 1af8a09966a ctdb-common: Set immediate mode for pcap capture
via 58e7d6a9451 ctdb-common: Replace pcap_open_live() by lower level calls
via 9f57371128d ctdb-common: Improve error handling
from 087e7cdc4d1 VERSION: Bump version up to Samba 4.19.0rc5...
https://git.samba.org/?p=samba.git;a=shortlog;h=v4-19-test
- Log -----------------------------------------------------------------
commit 1af8a09966a82a19d269cc1339232f271dff51bc
Author: Martin Schwenke <mschwenke at ddn.com>
Date: Tue Aug 15 12:34:20 2023 +1000
ctdb-common: Set immediate mode for pcap capture
Fix a problem where ctdb_killtcp (almost always) fails to capture
packets with --enable-pcap and libpcap ≥ 1.9.1. The problem is due to
a gradual change in libpcap semantics when using
pcap_get_selectable_fd(3PCAP) to get a file descriptor and then using
that file descriptor in non-blocking mode.
pcap_set_immediate_mode(3PCAP) says:
pcap_set_immediate_mode() sets whether immediate mode should be set
on a capture handle when the handle is activated. In immediate
mode, packets are always delivered as soon as they arrive, with no
buffering.
and
On Linux, with previous releases of libpcap, capture devices are
always in immediate mode; however, in 1.5.0 and later, they are, by
default, not in immediate mode, so if pcap_set_immediate_mode() is
available, it should be used.
However, it wasn't until libpcap commit
2ade7676101366983bd4f86bc039ffd25da8c126 (before libpcap 1.9.1) that
it became a requirement to use pcap_set_immediate_mode(), even with a
timeout of 0.
More explanation in this libpcap issue comment:
https://github.com/the-tcpdump-group/libpcap/issues/860#issuecomment-541204548
Do a configure check for pcap_set_immediate_mode() even though it has
existed for 10 years. It is easy enough.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15451
Signed-off-by: Martin Schwenke <mschwenke at ddn.com>
Reviewed-by: Amitay Isaacs <amitay at gmail.com>
Autobuild-User(master): Amitay Isaacs <amitay at samba.org>
Autobuild-Date(master): Tue Aug 15 10:53:52 UTC 2023 on atb-devel-224
(cherry picked from commit dc7b48c404337891b5105df4d6751cf549a533eb)
Autobuild-User(v4-19-test): Jule Anger <janger at samba.org>
Autobuild-Date(v4-19-test): Tue Aug 29 09:34:35 UTC 2023 on atb-devel-224
commit 58e7d6a945136fe9dd26810f4a22e48d9cf0943f
Author: Martin Schwenke <mschwenke at ddn.com>
Date: Tue Aug 15 10:57:59 2023 +1000
ctdb-common: Replace pcap_open_live() by lower level calls
A subsequent commit will insert an additional call before
pcap_activate().
This sequence of calls is taken from the source for pcap_open_live(),
so there should be no change in behaviour.
Given the defaults set by pcap_create_common(), it would be possible
to omit the calls to pcap_set_promisc() and pcap_set_timeout().
However, those defaults don't seem to be well documented, so continue
to explicitly set everything that was set before.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15451
Signed-off-by: Martin Schwenke <mschwenke at ddn.com>
Reviewed-by: Amitay Isaacs <amitay at gmail.com>
(cherry picked from commit ffc2ae616d8fab7528fbdfd8c6b94c5b9a0e3a7c)
commit 9f57371128d8ef40448651874857f445be6ed041
Author: Martin Schwenke <mschwenke at ddn.com>
Date: Tue Aug 15 10:43:57 2023 +1000
ctdb-common: Improve error handling
Factor out a failure label, which will get more use in subsequent
commits, and only set private_data when success is certain.
BUG: https://bugzilla.samba.org/show_bug.cgi?id=15451
Signed-off-by: Martin Schwenke <mschwenke at ddn.com>
Reviewed-by: Amitay Isaacs <amitay at gmail.com>
(cherry picked from commit d87041d8968e91db9d257445321b85693303f95e)
-----------------------------------------------------------------------
Summary of changes:
ctdb/common/system_socket.c | 42 ++++++++++++++++++++++++++++++++++++++----
ctdb/wscript | 1 +
2 files changed, 39 insertions(+), 4 deletions(-)
Changeset truncated at 500 lines:
diff --git a/ctdb/common/system_socket.c b/ctdb/common/system_socket.c
index 06dc558eb22..273b9c3400e 100644
--- a/ctdb/common/system_socket.c
+++ b/ctdb/common/system_socket.c
@@ -980,15 +980,45 @@ int ctdb_sys_open_capture_socket(const char *iface, void **private_data)
int pcap_packet_type;
const char *t = NULL;
int fd;
+ int ret;
- pt = pcap_open_live(iface, 100, 0, 0, errbuf);
+ pt = pcap_create(iface, errbuf);
if (pt == NULL) {
DBG_ERR("Failed to open pcap capture device %s (%s)\n",
iface,
errbuf);
return -1;
}
- *((pcap_t **)private_data) = pt;
+ /*
+ * pcap isn't very clear about defaults...
+ */
+ ret = pcap_set_snaplen(pt, 100);
+ if (ret < 0) {
+ DBG_ERR("Failed to set snaplen for pcap capture\n");
+ goto fail;
+ }
+ ret = pcap_set_promisc(pt, 0);
+ if (ret < 0) {
+ DBG_ERR("Failed to unset promiscuous mode for pcap capture\n");
+ goto fail;
+ }
+ ret = pcap_set_timeout(pt, 0);
+ if (ret < 0) {
+ DBG_ERR("Failed to set timeout for pcap capture\n");
+ goto fail;
+ }
+#ifdef HAVE_PCAP_SET_IMMEDIATE_MODE
+ ret = pcap_set_immediate_mode(pt, 1);
+ if (ret < 0) {
+ DBG_ERR("Failed to set immediate mode for pcap capture\n");
+ goto fail;
+ }
+#endif
+ ret = pcap_activate(pt);
+ if (ret < 0) {
+ DBG_ERR("Failed to activate pcap capture\n");
+ goto fail;
+ }
pcap_packet_type = pcap_datalink(pt);
switch (pcap_packet_type) {
@@ -1005,8 +1035,7 @@ int ctdb_sys_open_capture_socket(const char *iface, void **private_data)
#endif /* DLT_LINUX_SLL2 */
default:
DBG_ERR("Unknown pcap packet type %d\n", pcap_packet_type);
- pcap_close(pt);
- return -1;
+ goto fail;
}
fd = pcap_get_selectable_fd(pt);
@@ -1014,7 +1043,12 @@ int ctdb_sys_open_capture_socket(const char *iface, void **private_data)
t,
fd);
+ *((pcap_t **)private_data) = pt;
return fd;
+
+fail:
+ pcap_close(pt);
+ return -1;
}
int ctdb_sys_close_capture_socket(void *private_data)
diff --git a/ctdb/wscript b/ctdb/wscript
index 88e42439f5a..a7b04541014 100644
--- a/ctdb/wscript
+++ b/ctdb/wscript
@@ -221,6 +221,7 @@ def configure(conf):
if not conf.CHECK_FUNCS_IN('pcap_open_live', 'pcap', headers='pcap.h'):
Logs.error('Need libpcap')
sys.exit(1)
+ conf.CHECK_FUNCS_IN('pcap_set_immediate_mode', 'pcap', headers='pcap.h')
if not conf.CHECK_FUNCS_IN('backtrace backtrace_symbols', 'execinfo',
checklibc=True, headers='execinfo.h'):
--
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