diff options
Diffstat (limited to 'print-ppp.c')
| -rw-r--r-- | print-ppp.c | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/print-ppp.c b/print-ppp.c index baeb4f00..aba243dd 100644 --- a/print-ppp.c +++ b/print-ppp.c @@ -1363,7 +1363,7 @@ ppp_hdlc(netdissect_options *ndo, u_char *b, *t, c; const u_char *s; u_int i, proto; - const void *se; + const void *sb, *se; if (caplen == 0) return; @@ -1395,8 +1395,11 @@ ppp_hdlc(netdissect_options *ndo, /* * Change the end pointer, so bounds checks work. + * Change the pointer to packet data to help debugging. */ + sb = ndo->ndo_packetp; se = ndo->ndo_snapend; + ndo->ndo_packetp = b; ndo->ndo_snapend = t; length = ND_BYTES_AVAILABLE_AFTER(b); @@ -1425,18 +1428,26 @@ ppp_hdlc(netdissect_options *ndo, if (length < 4) goto trunc; proto = GET_BE_U_2(b + 2); /* load the PPP proto-id */ - handle_ppp(ndo, proto, b + 4, length - 4); + if ((proto & 0xff00) == 0x7e00) + ND_PRINT("(protocol 0x%04x invalid)", proto); + else + handle_ppp(ndo, proto, b + 4, length - 4); break; default: /* last guess - proto must be a PPP proto-id */ - handle_ppp(ndo, proto, b + 2, length - 2); + if ((proto & 0xff00) == 0x7e00) + ND_PRINT("(protocol 0x%04x invalid)", proto); + else + handle_ppp(ndo, proto, b + 2, length - 2); break; } cleanup: + ndo->ndo_packetp = sb; ndo->ndo_snapend = se; return; trunc: + ndo->ndo_packetp = sb; ndo->ndo_snapend = se; nd_print_trunc(ndo); } @@ -1559,11 +1570,18 @@ ppp_print(netdissect_options *ndo, hdr_len += 2; } - if (ndo->ndo_eflag) - ND_PRINT("%s (0x%04x), length %u: ", - tok2str(ppptype2str, "unknown", proto), + if (ndo->ndo_eflag) { + const char *typestr; + typestr = tok2str(ppptype2str, "unknown", proto); + ND_PRINT("%s (0x%04x), length %u", + typestr, proto, olen); + if (*typestr == 'u') /* "unknown" */ + return hdr_len; + + ND_PRINT(": "); + } handle_ppp(ndo, proto, p, length); return (hdr_len); |