{ 0, NULL }
};
-#define MSG_ANSI_LOCKING_SHIFT 0x95
+#define IE_IS_SINGLE_OCTET(iecode) ((iecode) & 0x80)
+#define IE_IS_SHIFT(iecode) (((iecode) & 0xF0) == 0x90)
+#define IE_SHIFT_IS_NON_LOCKING(iecode) ((iecode) & 0x08)
+#define IE_SHIFT_IS_LOCKING(iecode) (!(IE_SHIFT_IS_NON_LOCKING(iecode)))
+#define IE_SHIFT_CODESET(iecode) ((iecode) & 0x07)
#define FR_LMI_ANSI_REPORT_TYPE_IE 0x01
#define FR_LMI_ANSI_LINK_VERIFY_IE_91 0x19 /* details? */
{ 0, NULL }
};
-/* array of 16 codepages - currently we only support codepage 1,5 */
+/* array of 16 codesets - currently we only support codepage 0 and 5 */
static const struct tok *fr_q933_ie_codesets[] = {
- NULL,
fr_q933_ie_values_codeset5,
NULL,
NULL,
NULL,
+ NULL,
fr_q933_ie_values_codeset5,
NULL,
NULL,
NULL
};
-static int fr_q933_print_ie_codeset5(netdissect_options *ndo,
- const struct ie_tlv_header_t *ie_p, const u_char *p);
+static int fr_q933_print_ie_codeset5(netdissect_options *ndo, u_int iecode,
+ u_int ielength, const u_char *p);
-typedef int (*codeset_pr_func_t)(netdissect_options *,
- const struct ie_tlv_header_t *ie_p, const u_char *p);
+typedef int (*codeset_pr_func_t)(netdissect_options *, u_int iecode,
+ u_int ielength, const u_char *p);
-/* array of 16 codepages - currently we only support codepage 1,5 */
+/* array of 16 codesets - currently we only support codepage 0 and 5 */
static const codeset_pr_func_t fr_q933_print_ie_codeset[] = {
- NULL,
fr_q933_print_ie_codeset5,
NULL,
NULL,
NULL,
+ NULL,
fr_q933_print_ie_codeset5,
NULL,
NULL,
NULL
};
+/*
+ * ITU-T Q.933.
+ *
+ * p points to octet 2, the octet containing the length of the
+ * call reference value, so p[n] is octet n+2 ("octet X" is as
+ * used in Q.931/Q.933).
+ *
+ * XXX - actually used both for Q.931 and Q.933.
+ */
void
q933_print(netdissect_options *ndo,
const u_char *p, u_int length)
{
- const u_char *ptemp = p;
- const struct ie_tlv_header_t *ie_p;
u_int olen;
+ u_int call_ref_length, i;
+ uint8_t call_ref[15]; /* maximum length - length field is 4 bits */
+ u_int msgtype;
+ u_int iecode;
+ u_int ielength;
+ u_int codeset = 0;
u_int is_ansi = 0;
- u_int codeset;
- u_int ie_is_known = 0;
+ u_int ie_is_known;
+ u_int non_locking_shift;
+ u_int unshift_codeset;
- if (length < 9) /* shortest: Q.933a LINK VERIFY */
- goto trunc;
+ ND_PRINT((ndo, "%s", ndo->ndo_eflag ? "" : "Q.933"));
- ND_TCHECK2(*p, 3);
- codeset = p[2]&0x0f; /* extract the codeset */
-
- if (p[2] == MSG_ANSI_LOCKING_SHIFT) {
- is_ansi = 1;
+ if (length == 0) {
+ if (!ndo->ndo_eflag)
+ ND_PRINT((ndo, ", "));
+ ND_PRINT((ndo, "length %u", length));
+ goto trunc;
+ }
+ ND_TCHECK2(*p, 1);
+
+ /*
+ * Get the length of the call reference value.
+ */
+ olen = length; /* preserve the original length for display */
+ call_ref_length = (*p) & 0x0f;
+ p++;
+ length--;
+
+ /*
+ * Get the call reference value.
+ */
+ for (i = 0; i < call_ref_length; i++) {
+ if (length == 0) {
+ if (!ndo->ndo_eflag)
+ ND_PRINT((ndo, ", "));
+ ND_PRINT((ndo, "length %u", olen));
+ goto trunc;
+ }
+ ND_TCHECK2(*p, 1);
+ call_ref[i] = *p;
+ p++;
+ length--;
}
- ND_PRINT((ndo, "%s", ndo->ndo_eflag ? "" : "Q.933, "));
+ /*
+ * Get the message type.
+ */
+ if (length == 0) {
+ if (!ndo->ndo_eflag)
+ ND_PRINT((ndo, ", "));
+ ND_PRINT((ndo, "length %u", olen));
+ goto trunc;
+ }
+ ND_TCHECK2(*p, 1);
+ msgtype = *p;
+ p++;
+ length--;
+
+ /*
+ * Peek ahead to see if we start with a shift.
+ */
+ non_locking_shift = 0;
+ unshift_codeset = codeset;
+ if (length != 0) {
+ ND_TCHECK2(*p, 1);
+ iecode = *p;
+ if (IE_IS_SHIFT(iecode)) {
+ /*
+ * It's a shift. Skip over it.
+ */
+ p++;
+ length--;
+
+ /*
+ * Get the codeset.
+ */
+ codeset = IE_SHIFT_CODESET(iecode);
+
+ /*
+ * If it's a locking shift to codeset 5,
+ * mark this as ANSI. (XXX - 5 is actually
+ * for national variants in general, not
+ * the US variant in particular, but maybe
+ * this is more American exceptionalism. :-))
+ */
+ if (IE_SHIFT_IS_LOCKING(iecode)) {
+ /*
+ * It's a locking shift.
+ */
+ if (codeset == 5) {
+ /*
+ * It's a locking shift to
+ * codeset 5, so this is
+ * T1.617 Annex D.
+ */
+ is_ansi = 1;
+ }
+ } else {
+ /*
+ * It's a non-locking shift.
+ * Remember the current codeset, so we
+ * can revert to it after the next IE.
+ */
+ non_locking_shift = 1;
+ unshift_codeset = 0;
+ }
+ }
+ }
/* printing out header part */
+ if (!ndo->ndo_eflag)
+ ND_PRINT((ndo, ", "));
ND_PRINT((ndo, "%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset));
- if (p[0]) {
- ND_PRINT((ndo, ", Call Ref: 0x%02x", p[0]));
+ if (call_ref_length != 0) {
+ if (call_ref_length > 1 || p[0] != 0) {
+ /*
+ * Not a dummy call reference.
+ */
+ ND_PRINT((ndo, ", Call Ref: 0x"));
+ for (i = 0; i < call_ref_length; i++)
+ ND_PRINT((ndo, "%02x", call_ref[i]));
+ }
}
- if (ndo->ndo_vflag) {
- ND_PRINT((ndo, ", %s (0x%02x), length %u",
- tok2str(fr_q933_msg_values,
- "unknown message", p[1]),
- p[1],
- length));
- } else {
- ND_PRINT((ndo, ", %s",
+ if (ndo->ndo_vflag) {
+ ND_PRINT((ndo, ", %s (0x%02x), length %u",
+ tok2str(fr_q933_msg_values,
+ "unknown message", msgtype),
+ msgtype,
+ olen));
+ } else {
+ ND_PRINT((ndo, ", %s",
tok2str(fr_q933_msg_values,
- "unknown message 0x%02x", p[1])));
+ "unknown message 0x%02x", msgtype)));
}
- olen = length; /* preserve the original length for non verbose mode */
-
- if (length < 2 + is_ansi) {
- ND_PRINT((ndo, "[|q.933]"));
+ if (length == 0) {
+ if (!ndo->ndo_eflag)
+ ND_PRINT((ndo, ", "));
+ ND_PRINT((ndo, "length %u", olen));
return;
}
- length -= 2 + is_ansi;
- ptemp += 2 + is_ansi;
-
- /* Loop through the rest of IE */
- while (length > sizeof(struct ie_tlv_header_t)) {
- ie_p = (const struct ie_tlv_header_t *)ptemp;
- if (length < sizeof(struct ie_tlv_header_t) ||
- length < sizeof(struct ie_tlv_header_t) + ie_p->ie_len) {
- if (ndo->ndo_vflag) { /* not bark if there is just a trailer */
- ND_PRINT((ndo, "\n[|q.933]"));
- } else {
- ND_PRINT((ndo, ", length %u", olen));
- }
- return;
- }
- if (!ND_TTEST(*ie_p)) {
- if (ndo->ndo_vflag)
- ND_PRINT((ndo, "\n"));
- ND_PRINT((ndo, "\n[|q.933]"));
- return;
- }
-
- /* lets do the full IE parsing only in verbose mode
- * however some IEs (DLCI Status, Link Verify)
- * are also interestting in non-verbose mode */
- if (ndo->ndo_vflag) {
- ND_PRINT((ndo, "\n\t%s IE (0x%02x), length %u: ",
- tok2str(fr_q933_ie_codesets[codeset],
- "unknown", ie_p->ie_type),
- ie_p->ie_type,
- ie_p->ie_len));
- }
-
- /* sanity checks */
- if (ie_p->ie_type == 0 || ie_p->ie_len == 0) {
- return;
- }
- if (length < ie_p->ie_len + 2U) {
- goto trunc;
- }
- ND_TCHECK2(*ptemp, ie_p->ie_len + 2U);
- if (fr_q933_print_ie_codeset[codeset] != NULL) {
- ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, ie_p, ptemp);
+ /* Loop through the rest of the IEs */
+ while (length != 0) {
+ /*
+ * What's the state of any non-locking shifts?
+ */
+ if (non_locking_shift == 1) {
+ /*
+ * There's a non-locking shift in effect for
+ * this IE. Count it, so we reset the codeset
+ * before the next IE.
+ */
+ non_locking_shift = 2;
+ } else if (non_locking_shift == 2) {
+ /*
+ * Unshift.
+ */
+ codeset = unshift_codeset;
+ non_locking_shift = 0;
}
- if (ndo->ndo_vflag >= 1 && !ie_is_known) {
- print_unknown_data(ndo, ptemp+2, "\n\t", ie_p->ie_len);
- }
+ /*
+ * Get the first octet of the IE.
+ */
+ ND_TCHECK2(*p, 1);
+ iecode = *p;
+ p++;
+ length--;
- /* do we want to see a hexdump of the IE ? */
- if (ndo->ndo_vflag> 1 && ie_is_known) {
- print_unknown_data(ndo, ptemp+2, "\n\t ", ie_p->ie_len);
+ /* Single-octet IE? */
+ if (IE_IS_SINGLE_OCTET(iecode)) {
+ /*
+ * Yes. Is it a shift?
+ */
+ if (IE_IS_SHIFT(iecode)) {
+ /*
+ * Yes. Is it locking?
+ */
+ if (IE_SHIFT_IS_LOCKING(iecode)) {
+ /*
+ * Yes.
+ */
+ non_locking_shift = 0;
+ } else {
+ /*
+ * No. Remember the current
+ * codeset, so we can revert
+ * to it after the next IE.
+ */
+ non_locking_shift = 1;
+ unshift_codeset = codeset;
+ }
+
+ /*
+ * Get the codeset.
+ */
+ codeset = IE_SHIFT_CODESET(iecode);
+ }
+ } else {
+ /*
+ * No. Get the IE length.
+ */
+ if (length == 0) {
+ if (ndo->ndo_vflag) {
+ ND_PRINT((ndo, "\n"));
+ } else {
+ ND_PRINT((ndo, ", length %u", olen));
+ }
+ goto trunc;
+ }
+ if (!ND_TTEST2(*p, 1)) {
+ if (ndo->ndo_vflag) {
+ ND_PRINT((ndo, "\n"));
+ } else {
+ ND_PRINT((ndo, ", length %u", olen));
+ }
+ goto trunc;
+ }
+ ielength = *p;
+ p++;
+ length--;
+
+ /* lets do the full IE parsing only in verbose mode
+ * however some IEs (DLCI Status, Link Verify)
+ * are also interesting in non-verbose mode */
+ if (ndo->ndo_vflag) {
+ ND_PRINT((ndo, "\n\t%s IE (0x%02x), length %u: ",
+ tok2str(fr_q933_ie_codesets[codeset],
+ "unknown", iecode),
+ iecode,
+ ielength));
+ }
+
+ /* sanity checks */
+ if (iecode == 0 || ielength == 0) {
+ return;
+ }
+ if (length < ielength) {
+ if (!ndo->ndo_vflag) {
+ ND_PRINT((ndo, ", length %u", olen));
+ }
+ goto trunc;
+ }
+ if (!ND_TTEST2(*p, ielength)) {
+ if (!ndo->ndo_vflag) {
+ ND_PRINT((ndo, ", length %u", olen));
+ }
+ goto trunc;
+ }
+
+ ie_is_known = 0;
+ if (fr_q933_print_ie_codeset[codeset] != NULL) {
+ ie_is_known = fr_q933_print_ie_codeset[codeset](ndo, iecode, ielength, p);
+ }
+
+ if (ie_is_known) {
+ /*
+ * Known IE; do we want to see a hexdump
+ * of it?
+ */
+ if (ndo->ndo_vflag > 1) {
+ /* Yes. */
+ print_unknown_data(ndo, p, "\n\t ", ielength);
+ }
+ } else {
+ /*
+ * Unknown IE; if we're printing verbosely,
+ * print its content in hex.
+ */
+ if (ndo->ndo_vflag >= 1) {
+ print_unknown_data(ndo, p, "\n\t", ielength);
+ }
+ }
+
+ length -= ielength;
+ p += ielength;
}
-
- length -= ie_p->ie_len + 2U;
- ptemp += ie_p->ie_len + 2U;
}
- if (!ndo->ndo_vflag) {
- ND_PRINT((ndo, ", length %u", olen));
+ if (!ndo->ndo_vflag) {
+ ND_PRINT((ndo, ", length %u", olen));
}
return;
}
static int
-fr_q933_print_ie_codeset5(netdissect_options *ndo,
- const struct ie_tlv_header_t *ie_p, const u_char *p)
+fr_q933_print_ie_codeset5(netdissect_options *ndo, u_int iecode,
+ u_int ielength, const u_char *p)
{
u_int dlci;
- switch (ie_p->ie_type) {
+ switch (iecode) {
case FR_LMI_ANSI_REPORT_TYPE_IE: /* fall through */
case FR_LMI_CCITT_REPORT_TYPE_IE:
if (ndo->ndo_vflag) {
ND_PRINT((ndo, "%s (%u)",
- tok2str(fr_lmi_report_type_ie_values,"unknown",p[2]),
- p[2]));
+ tok2str(fr_lmi_report_type_ie_values,"unknown",p[0]),
+ p[0]));
}
return 1;
if (!ndo->ndo_vflag) {
ND_PRINT((ndo, ", "));
}
- ND_PRINT((ndo, "TX Seq: %3d, RX Seq: %3d", p[2], p[3]));
+ ND_PRINT((ndo, "TX Seq: %3d, RX Seq: %3d", p[0], p[1]));
return 1;
case FR_LMI_ANSI_PVC_STATUS_IE: /* fall through */
ND_PRINT((ndo, ", "));
}
/* now parse the DLCI information element. */
- if ((ie_p->ie_len < 3) ||
- (p[2] & 0x80) ||
- ((ie_p->ie_len == 3) && !(p[3] & 0x80)) ||
- ((ie_p->ie_len == 4) && ((p[3] & 0x80) || !(p[4] & 0x80))) ||
- ((ie_p->ie_len == 5) && ((p[3] & 0x80) || (p[4] & 0x80) ||
- !(p[5] & 0x80))) ||
- (ie_p->ie_len > 5) ||
- !(p[ie_p->ie_len + 1] & 0x80)) {
+ if ((ielength < 3) ||
+ (p[0] & 0x80) ||
+ ((ielength == 3) && !(p[1] & 0x80)) ||
+ ((ielength == 4) && ((p[1] & 0x80) || !(p[2] & 0x80))) ||
+ ((ielength == 5) && ((p[1] & 0x80) || (p[2] & 0x80) ||
+ !(p[3] & 0x80))) ||
+ (ielength > 5) ||
+ !(p[ielength - 1] & 0x80)) {
ND_PRINT((ndo, "Invalid DLCI IE"));
}
- dlci = ((p[2] & 0x3F) << 4) | ((p[3] & 0x78) >> 3);
- if (ie_p->ie_len == 4) {
- dlci = (dlci << 6) | ((p[4] & 0x7E) >> 1);
+ dlci = ((p[0] & 0x3F) << 4) | ((p[1] & 0x78) >> 3);
+ if (ielength == 4) {
+ dlci = (dlci << 6) | ((p[2] & 0x7E) >> 1);
}
- else if (ie_p->ie_len == 5) {
- dlci = (dlci << 13) | (p[4] & 0x7F) | ((p[5] & 0x7E) >> 1);
+ else if (ielength == 5) {
+ dlci = (dlci << 13) | (p[2] & 0x7F) | ((p[3] & 0x7E) >> 1);
}
ND_PRINT((ndo, "DLCI %u: status %s%s", dlci,
- p[ie_p->ie_len + 1] & 0x8 ? "New, " : "",
- p[ie_p->ie_len + 1] & 0x2 ? "Active" : "Inactive"));
+ p[ielength - 1] & 0x8 ? "New, " : "",
+ p[ielength - 1] & 0x2 ? "Active" : "Inactive"));
return 1;
}
projects / tcpdump / commitdiff
