From: Vadim Kochan <[email protected]>
mz fails start in cli mode and prints each time different pcap errors:
$ mz -x -V
fatal flex scanner internal error--end of buffer missed
rx_arp: [ERROR] Error calling pcap_compile
or simply shutdowns. Sometimes it successfully gets up.
Seems some initialization pcap funcs are not thread safer.
Fixed by using mutex locking before entering pcap loop.
Signed-off-by: Vadim Kochan <[email protected]>
---
locking.h | 2 ++
staging/mopsrx_arp.c | 21 ++++++++++++++++-----
2 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/locking.h b/locking.h
index cb57a9d..2cd8d24 100644
--- a/locking.h
+++ b/locking.h
@@ -11,6 +11,8 @@ struct mutexlock {
pthread_mutex_t lock;
};
+#define MUTEXLOCK_INIT() { .lock = PTHREAD_MUTEX_INITIALIZER }
+
struct rwlock {
pthread_rwlock_t lock;
};
diff --git a/staging/mopsrx_arp.c b/staging/mopsrx_arp.c
index baf8133..b1f1493 100644
--- a/staging/mopsrx_arp.c
+++ b/staging/mopsrx_arp.c
@@ -19,6 +19,9 @@
#include "mz.h"
#include "mops.h"
#include "cli.h"
+#include "locking.h"
+
+static struct mutexlock pcap_init_lock = MUTEXLOCK_INIT();
// Starts an ARP RX thread for *every* device in the device_list.
// (Except for the loopback interface)
@@ -67,6 +70,8 @@ void *rx_arp (void *arg)
// FYI, possible filter string is also:
// "eth.dst==00:05:4e:51:01:b5 and arp and arp.opcode==2";
+ mutexlock_lock(&pcap_init_lock);
+
p_arp = pcap_open_live (dev->dev,
100, // max num of bytes to read
1, // 1 if promiscuous mode
@@ -75,7 +80,7 @@ void *rx_arp (void *arg)
if (p_arp == NULL) {
fprintf(stderr," rx_arp: [ERROR] %s\n",errbuf);
- return NULL; // TODO: Should return pointer to error message or
something similar
+ goto Exit_unlock;
}
dev->p_arp = p_arp; // also assign pointer to a global which is needed
for clean_up
@@ -87,20 +92,22 @@ void *rx_arp (void *arg)
0) // netmask
== -1) {
fprintf(stderr," rx_arp: [ERROR] Error calling
pcap_compile\n");
- return NULL;
+ goto Exit_unlock;
}
if ( pcap_setfilter(p_arp, &filter) == -1) {
fprintf(stderr," rx_arp: [ERROR] Error setting pcap filter\n");
pcap_perror(p_arp, " rx_arp: ");
- return NULL;
+ goto Exit_unlock;
}
if (pcap_setdirection(p_arp, PCAP_D_IN) == -1) {
pcap_perror(p_arp, " rx_arp: ");
- return NULL;
+ goto Exit_unlock;
}
+ mutexlock_unlock(&pcap_init_lock);
+
again:
pcap_loop (p_arp,
1, // number of packets to wait
@@ -109,7 +116,11 @@ void *rx_arp (void *arg)
goto again;
pthread_exit(NULL); // destroy thread
- return NULL;
+ return NULL;
+
+Exit_unlock:
+ mutexlock_unlock(&pcap_init_lock);
+ return NULL;
}
--
2.3.1
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