{
const struct mp_capable *mpc = (const struct mp_capable *) opt;
- if (!(opt_len == 12 && flags & TH_SYN) &&
+ if (!(opt_len == 12 && (flags & TH_SYN)) &&
!(opt_len == 20 && (flags & (TH_SYN | TH_ACK)) == TH_ACK))
return 0;
{
const struct mp_join *mpj = (const struct mp_join *) opt;
- if (!(opt_len == 12 && flags & TH_SYN) &&
+ if (!(opt_len == 12 && (flags & TH_SYN)) &&
!(opt_len == 16 && (flags & (TH_SYN | TH_ACK)) == (TH_SYN | TH_ACK)) &&
- !(opt_len == 24 && flags & TH_ACK))
+ !(opt_len == 24 && (flags & TH_ACK)))
return 0;
if (opt_len != 24) {
return 1;
}
-static u_int mp_dss_len(const struct mp_dss *m, int csum)
-{
- u_int len;
-
- len = 4;
- if (m->flags & MP_DSS_A) {
- /* Ack present - 4 or 8 octets */
- len += (m->flags & MP_DSS_a) ? 8 : 4;
- }
- if (m->flags & MP_DSS_M) {
- /*
- * Data Sequence Number (DSN), Subflow Sequence Number (SSN),
- * Data-Level Length present, and Checksum possibly present.
- * All but the Checksum are 10 bytes if the m flag is
- * clear (4-byte DSN) and 14 bytes if the m flag is set
- * (8-byte DSN).
- */
- len += (m->flags & MP_DSS_m) ? 14 : 10;
-
- /*
- * The Checksum is present only if negotiated.
- */
- if (csum)
- len += 2;
- }
- return len;
-}
-
static int
mp_dss_print(netdissect_options *ndo,
const u_char *opt, u_int opt_len, u_char flags)
{
const struct mp_dss *mdss = (const struct mp_dss *) opt;
- if ((opt_len != mp_dss_len(mdss, 1) &&
- opt_len != mp_dss_len(mdss, 0)) || flags & TH_SYN)
+ /* We need the flags, at a minimum. */
+ if (opt_len < 4)
+ return 0;
+
+ if (flags & TH_SYN)
return 0;
if (mdss->flags & MP_DSS_F)
ND_PRINT((ndo, " fin"));
opt += 4;
+ opt_len -= 4;
if (mdss->flags & MP_DSS_A) {
+ /* Ack present */
ND_PRINT((ndo, " ack "));
+ /*
+ * If the a flag is set, we have an 8-byte ack; if it's
+ * clear, we have a 4-byte ack.
+ */
if (mdss->flags & MP_DSS_a) {
+ if (opt_len < 8)
+ return 0;
ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
opt += 8;
+ opt_len -= 8;
} else {
+ if (opt_len < 4)
+ return 0;
ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
opt += 4;
+ opt_len -= 4;
}
}
if (mdss->flags & MP_DSS_M) {
+ /*
+ * Data Sequence Number (DSN), Subflow Sequence Number (SSN),
+ * Data-Level Length present, and Checksum possibly present.
+ */
ND_PRINT((ndo, " seq "));
+ /*
+ * If the m flag is set, we have an 8-byte NDS; if it's clear,
+ * we have a 4-byte DSN.
+ */
if (mdss->flags & MP_DSS_m) {
+ if (opt_len < 8)
+ return 0;
ND_PRINT((ndo, "%" PRIu64, EXTRACT_64BITS(opt)));
opt += 8;
+ opt_len -= 8;
} else {
+ if (opt_len < 4)
+ return 0;
ND_PRINT((ndo, "%u", EXTRACT_32BITS(opt)));
opt += 4;
+ opt_len -= 4;
}
+ if (opt_len < 4)
+ return 0;
ND_PRINT((ndo, " subseq %u", EXTRACT_32BITS(opt)));
opt += 4;
+ opt_len -= 4;
+ if (opt_len < 2)
+ return 0;
ND_PRINT((ndo, " len %u", EXTRACT_16BITS(opt)));
opt += 2;
+ opt_len -= 2;
- if (opt_len == mp_dss_len(mdss, 1))
+ /*
+ * The Checksum is present only if negotiated.
+ * If there are at least 2 bytes left, process the next 2
+ * bytes as the Checksum.
+ */
+ if (opt_len >= 2) {
ND_PRINT((ndo, " csum 0x%x", EXTRACT_16BITS(opt)));
+ opt_len -= 2;
+ }
}
+ if (opt_len != 0)
+ return 0;
return 1;
}