tcpdump mailing list archives
segfault in pcap_snapshot
From: Karl Sjödahl <karlsjod01 () student kau se>
Date: Sun, 22 Feb 2004 23:35:21 +0100
Hi. Im tryin to write a simple sniffer with libpcap but I have some problems that I cant be able to solve and its starting to get frustrating. Code: #define FILTER udp or tcp #define PROMISC 1 ... if(pcap_open_live(device, BUFSIZ, PROMISC, 0, errbuf) == -1) { error handling } if(pcap_lookupnet(device, &local_net, &netmask, errbuf) == -1) { error handling } if(pcap_compile(p, &filter_code, TESTFILTER, 0, netmask) == -1) { error handling } if(pcap_setfilter(p, &filter_code) == -1) { error handling } After pcap_lookupnet the program segfaults. I have tested everything with pcap_compile and I cant understabd what is wrong. Program received signal SIGSEGV, Segmentation fault. 0x88208ac in pcap_snapshot () (gdb) And it says there is an error in pcap_snapshot. If i put a break on pcap_compile and step through it it looks like this: Breakpoint 1, 0x8821d0c in pcap_compile () (gdb) ni 0x8821d10 in pcap_compile () (gdb) 0x8821d14 in pcap_compile () (gdb) 0x8821b4c in bpf_filter () (gdb) 0x8821b50 in bpf_filter () (gdb) 0x8821d18 in pcap_compile () (gdb) 0x8821d1c in pcap_compile () (gdb) 0x8821d20 in pcap_compile () (gdb) 0x8821d24 in pcap_compile () (gdb) 0x8821d28 in pcap_compile () (gdb) 0x8821d2c in pcap_compile () (gdb) 0x8821d30 in pcap_compile () (gdb) 0x8821d34 in pcap_compile () (gdb) 0x8821d38 in pcap_compile () (gdb) 0x8821d3c in pcap_compile () (gdb) 0x8821d40 in pcap_compile () (gdb) 0x8821d44 in pcap_compile () (gdb) 0x8821d48 in pcap_compile () (gdb) 0x8821d4c in pcap_compile () (gdb) 0x8821d50 in pcap_compile () (gdb) 0x8821d54 in pcap_compile () (gdb) 0x8b34170 in __DTOR_LIST__ () (gdb) 0x8b34174 in __DTOR_LIST__ () (gdb) 0x8b34128 in __DTOR_LIST__ () (gdb) 0x8b3412c in __DTOR_LIST__ () (gdb) 0x8b34130 in __DTOR_LIST__ () (gdb) Program received signal SIGBUS, Bus error. 0x82141c4 in _dl_bind () (gdb) Anybody that can see any errors or can point me in the right direction where to find good info on how I can write the pcap_compile because it looks like there error is made there or maybe in the creation of p. Thanks. // Dunceor --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.593 / Virus Database: 376 - Release Date: 2004-02-20
Current thread:
- segfault in pcap_snapshot Karl Sjödahl (Feb 22)
- Re: segfault in pcap_snapshot Guy Harris (Feb 22)
- SV: segfault in pcap_snapshot Karl Sjödahl (Feb 22)
- Re: segfault in pcap_snapshot Guy Harris (Feb 22)