diff options
| author | hannes <hannes> | 2006-02-24 12:18:03 +0000 |
|---|---|---|
| committer | hannes <hannes> | 2006-02-24 12:18:03 +0000 |
| commit | 0f3fba52a6adfe54e71dc35d8d307fab5d52bf88 (patch) | |
| tree | 8a935af3bf42008cf4d7ce48319c99d2b073d0c7 /print-juniper.c | |
| parent | 50b4920bc51263ce3a2647b6a1d2289629650854 (diff) | |
| download | tcpdump-0f3fba52a6adfe54e71dc35d8d307fab5d52bf88.tar.gz | |
improve Control Word detection heuristics for OAM cells
Diffstat (limited to 'print-juniper.c')
| -rw-r--r-- | print-juniper.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/print-juniper.c b/print-juniper.c index 9b0a70fd..7dfc06cf 100644 --- a/print-juniper.c +++ b/print-juniper.c @@ -15,7 +15,7 @@ #ifndef lint static const char rcsid[] _U_ = - "@(#) $Header: /tcpdump/master/tcpdump/print-juniper.c,v 1.29 2006-02-01 14:42:17 hannes Exp $ (LBL)"; + "@(#) $Header: /tcpdump/master/tcpdump/print-juniper.c,v 1.30 2006-02-24 12:18:03 hannes Exp $ (LBL)"; #endif #ifdef HAVE_CONFIG_H @@ -710,7 +710,6 @@ u_int juniper_atm2_print(const struct pcap_pkthdr *h, register const u_char *p) { u_int16_t extracted_ethertype; - u_int32_t control_word; struct juniper_l2info_t l2info; @@ -721,12 +720,6 @@ juniper_atm2_print(const struct pcap_pkthdr *h, register const u_char *p) p+=l2info.header_len; if (l2info.cookie[7] & ATM2_PKT_TYPE_MASK) { /* OAM cell ? */ - control_word = EXTRACT_32BITS(p); - if(control_word == 0 || control_word == 0x08000000) { - l2info.header_len += 4; - l2info.length -= 4; - p += 4; - } oam_print(p,l2info.length,ATM_OAM_NOHEC); return l2info.header_len; } @@ -890,6 +883,7 @@ juniper_parse_header (const u_char *p, const struct pcap_pkthdr *h, struct junip struct juniper_cookie_table_t *lp = juniper_cookie_table; u_int idx, jnx_ext_len, jnx_header_len = 0; u_int8_t tlv_type,tlv_len; + u_int32_t control_word; int tlv_value; const u_char *tptr; @@ -1130,10 +1124,21 @@ juniper_parse_header (const u_char *p, const struct pcap_pkthdr *h, struct junip case DLT_JUNIPER_ATM2: TCHECK2(p[0],4); /* ATM cell relay control word present ? */ - if (l2info->cookie[7] & ATM2_PKT_TYPE_MASK && *p & 0x08) { - l2info->header_len += 4; + if (l2info->cookie[7] & ATM2_PKT_TYPE_MASK) { + control_word = EXTRACT_32BITS(p); + /* some control word heuristics */ + switch(control_word) { + case 0: /* zero control word */ + case 0x08000000: /* < JUNOS 7.4 control-word */ + case 0x08380000: /* cntl word plus cell length (56) >= JUNOS 7.4*/ + l2info->header_len += 4; + break; + default: + break; + } + if (eflag) - printf("control-word 0x%08x ",EXTRACT_32BITS(p)); + printf("control-word 0x%08x ", control_word); } break; #endif |