From: Guy Harris Date: Wed, 10 Jan 2018 21:18:47 +0000 (-0800) Subject: Fix VoIP VLAN request/assignment, clean up signed vs. unsigned. X-Git-Tag: tcpdump-4.99-bp~1473 X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/cbe647350e454cb90dfeaf34cd8c6a297ef6cb59 Fix VoIP VLAN request/assignment, clean up signed vs. unsigned. 0x000f is a query for a VoIP VLAN ID, 0x000e is the reply for that. 0x0010 is a power consumption message. Display 2-byte VoIP VLAN queries. Treat 2-byte VoIP VLAN replies as errors; I've seen the former but not the latter. Don't use unsigned long for values that fit in an unsigned int. --- diff --git a/print-cdp.c b/print-cdp.c index d07a62fb..1f0f07cd 100644 --- a/print-cdp.c +++ b/print-cdp.c @@ -62,8 +62,8 @@ static const struct tok cdp_tlv_values[] = { { 0x09, "VTP Management Domain"}, { 0x0a, "Native VLAN ID"}, { 0x0b, "Duplex"}, - { 0x0e, "ATA-186 VoIP VLAN request"}, - { 0x0f, "ATA-186 VoIP VLAN assignment"}, + { 0x0e, "ATA-186 VoIP VLAN assignment"}, + { 0x0f, "ATA-186 VoIP VLAN request"}, { 0x10, "power consumption"}, { 0x11, "MTU"}, { 0x12, "AVVID trust bitmap"}, @@ -86,15 +86,15 @@ static const struct tok cdp_capability_values[] = { { 0, NULL } }; -static int cdp_print_addr(netdissect_options *, const u_char *, int); -static int cdp_print_prefixes(netdissect_options *, const u_char *, int); -static unsigned long cdp_get_number(const u_char *, int); +static int cdp_print_addr(netdissect_options *, const u_char *, u_int); +static int cdp_print_prefixes(netdissect_options *, const u_char *, u_int); +static unsigned int cdp_get_number(const u_char *, u_int); void cdp_print(netdissect_options *ndo, const u_char *pptr, u_int length, u_int caplen) { - int type, len, i, j; + u_int type, len, i, j; const u_char *tptr; if (caplen < CDP_HEADER_LEN) { @@ -197,7 +197,7 @@ cdp_print(netdissect_options *ndo, case 0x0a: /* Native VLAN ID - CDPv2 */ if (len < 2) goto trunc; - ND_PRINT("%d", EXTRACT_BE_U_2(tptr)); + ND_PRINT("%u", EXTRACT_BE_U_2(tptr)); break; case 0x0b: /* Duplex - CDPv2 */ if (len < 1) @@ -207,13 +207,30 @@ cdp_print(netdissect_options *ndo, /* http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cata/186/2_12_m/english/release/notes/186rn21m.html * plus more details from other sources + * + * There are apparently versions of the request with both + * 2 bytes and 3 bytes of value. The 3 bytes of value + * appear to be a 1-byte application type followed by a + * 2-byte VLAN ID; the 2 bytes of value are unknown + * (they're 0x20 0x00 in some captures I've seen; that + * is not a valid VLAN ID, as VLAN IDs are 12 bits). + * + * The replies all appear to be 3 bytes long. */ - case 0x0e: /* ATA-186 VoIP VLAN request - incomplete doc. */ + case 0x0e: /* ATA-186 VoIP VLAN assignment - incomplete doc. */ if (len < 3) goto trunc; - ND_PRINT("app %d, vlan %d", EXTRACT_U_1((tptr)), EXTRACT_BE_U_2(tptr + 1)); + ND_PRINT("app %u, vlan %u", EXTRACT_U_1(tptr), EXTRACT_BE_U_2(tptr + 1)); break; - case 0x10: /* ATA-186 VoIP VLAN assignment - incomplete doc. */ + case 0x0f: /* ATA-186 VoIP VLAN request - incomplete doc. */ + if (len < 2) + goto trunc; + if (len == 2) + ND_PRINT("unknown 0x%04x", EXTRACT_BE_U_2(tptr)); + else + ND_PRINT("app %u, vlan %u", EXTRACT_U_1(tptr), EXTRACT_BE_U_2(tptr + 1)); + break; + case 0x10: /* Power - not documented */ ND_PRINT("%1.2fW", cdp_get_number(tptr, len) / 1000.0); break; case 0x11: /* MTU - not documented */ @@ -277,9 +294,9 @@ trunc: static int cdp_print_addr(netdissect_options *ndo, - const u_char * p, int l) + const u_char * p, u_int l) { - int pt, pl, al, num; + u_int pt, pl, al, num; const u_char *endp = p + l; static const u_char prot_ipv6[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00, 0x86, 0xdd @@ -291,12 +308,12 @@ cdp_print_addr(netdissect_options *ndo, num = EXTRACT_BE_U_4(p); p += 4; - while (p < endp && num >= 0) { + while (p < endp && num != 0) { ND_TCHECK_2(p); if (p + 2 > endp) goto trunc; pt = EXTRACT_U_1(p); /* type of "protocol" field */ - pl = EXTRACT_U_1(p + 1); /* length of "protocol" field */ + pl = EXTRACT_U_1(p + 1); /* length of "protocol" field */ p += 2; ND_TCHECK_2(p + pl); @@ -342,7 +359,7 @@ cdp_print_addr(netdissect_options *ndo, ND_TCHECK_LEN(p, pl); if (p + pl > endp) goto trunc; - ND_PRINT("pt=0x%02x, pl=%d, pb=", EXTRACT_U_1((p - 2)), pl); + ND_PRINT("pt=0x%02x, pl=%u, pb=", EXTRACT_U_1((p - 2)), pl); while (pl-- > 0) { ND_PRINT(" %02x", EXTRACT_U_1(p)); p++; @@ -350,7 +367,7 @@ cdp_print_addr(netdissect_options *ndo, ND_TCHECK_2(p); if (p + 2 > endp) goto trunc; - ND_PRINT(", al=%d, a=", al); + ND_PRINT(", al=%u, a=", al); p += 2; ND_TCHECK_LEN(p, al); if (p + al > endp) @@ -374,12 +391,12 @@ trunc: static int cdp_print_prefixes(netdissect_options *ndo, - const u_char * p, int l) + const u_char * p, u_int l) { if (l % 5) goto trunc; - ND_PRINT(" IPv4 Prefixes (%d):", l / 5); + ND_PRINT(" IPv4 Prefixes (%u):", l / 5); while (l > 0) { ND_PRINT(" %u.%u.%u.%u/%u", @@ -396,11 +413,11 @@ trunc: } /* read in a -byte number, MSB first - * (of course this can handle max sizeof(long)) + * (of course this can handle max sizeof(int)) */ -static unsigned long cdp_get_number(const u_char * p, int l) +static unsigned int cdp_get_number(const u_char * p, u_int l) { - unsigned long res=0; + unsigned int res=0; while( l>0 ) { res = (res<<8) + EXTRACT_U_1(p);