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--- ppp-2.4.2/pppd/cbcp.c 2004-10-28 15:14:19.231292272 -0400
+++ ppp-cvs/pppd/cbcp.c 2004-10-27 20:15:36.000000000 -0400
@@ -33,7 +33,7 @@
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
-#define RCSID "$Id: cbcp-dosfix.patch,v 1.1 2004/10/30 12:38:53 dragonheart Exp $"
+#define RCSID "$Id: cbcp-dosfix.patch,v 1.1 2004/10/30 12:38:53 dragonheart Exp $"
#include <stdio.h>
#include <string.h>
@@ -165,7 +165,8 @@
inp = inpacket;
if (pktlen < CBCP_MINLEN) {
- error("CBCP packet is too small");
+ if (debug)
+ dbglog("CBCP packet is too small");
return;
}
@@ -173,12 +174,11 @@
GETCHAR(id, inp);
GETSHORT(len, inp);
-#if 0
- if (len > pktlen) {
- error("CBCP packet: invalid length");
+ if (len > pktlen || len < CBCP_MINLEN) {
+ if (debug)
+ dbglog("CBCP packet: invalid length %d", len);
return;
}
-#endif
len -= CBCP_MINLEN;
@@ -189,11 +189,12 @@
break;
case CBCP_RESP:
- dbglog("CBCP_RESP received");
+ if (debug)
+ dbglog("CBCP_RESP received");
break;
case CBCP_ACK:
- if (id != us->us_id)
+ if (debug && id != us->us_id)
dbglog("id doesn't match: expected %d recv %d",
us->us_id, id);
@@ -312,11 +313,13 @@
address[0] = 0;
- while (len) {
+ while (len >= 2) {
dbglog("length: %d", len);
GETCHAR(type, pckt);
GETCHAR(opt_len, pckt);
+ if (opt_len < 2 || opt_len > len)
+ break;
if (opt_len > 2)
GETCHAR(delay, pckt);
@@ -348,6 +351,11 @@
}
len -= opt_len;
}
+ if (len != 0) {
+ if (debug)
+ dbglog("cbcp_recvreq: malformed packet (%d bytes left)", len);
+ return;
+ }
cbcp_resp(us);
}
@@ -360,6 +368,7 @@
u_char buf[256];
u_char *bufp = buf;
int len = 0;
+ int slen;
cb_type = us->us_allowed & us->us_type;
dbglog("cbcp_resp cb_type=%d", cb_type);
@@ -371,12 +380,17 @@
if (cb_type & ( 1 << CB_CONF_USER ) ) {
dbglog("cbcp_resp CONF_USER");
+ slen = strlen(us->us_number);
+ if (slen > 250) {
+ warn("callback number truncated to 250 characters");
+ slen = 250;
+ }
PUTCHAR(CB_CONF_USER, bufp);
- len = 3 + 1 + strlen(us->us_number) + 1;
+ len = 3 + 1 + slen + 1;
PUTCHAR(len , bufp);
PUTCHAR(5, bufp); /* delay */
PUTCHAR(1, bufp);
- BCOPY(us->us_number, bufp, strlen(us->us_number) + 1);
+ BCOPY(us->us_number, bufp, slen + 1);
cbcp_send(us, CBCP_RESP, buf, len);
return;
}
@@ -438,25 +452,29 @@
int opt_len;
char address[256];
- if (len) {
+ if (len >= 2) {
GETCHAR(type, pckt);
GETCHAR(opt_len, pckt);
+ if (opt_len >= 2 && opt_len <= len) {
- if (opt_len > 2)
- GETCHAR(delay, pckt);
+ if (opt_len > 2)
+ GETCHAR(delay, pckt);
- if (opt_len > 4) {
- GETCHAR(addr_type, pckt);
- memcpy(address, pckt, opt_len - 4);
- address[opt_len - 4] = 0;
- if (address[0])
- dbglog("peer will call: %s", address);
- }
- if (type == CB_CONF_NO)
- return;
- }
+ if (opt_len > 4) {
+ GETCHAR(addr_type, pckt);
+ memcpy(address, pckt, opt_len - 4);
+ address[opt_len - 4] = 0;
+ if (address[0])
+ dbglog("peer will call: %s", address);
+ }
+ if (type == CB_CONF_NO)
+ return;
- cbcp_up(us);
+ cbcp_up(us);
+
+ } else if (debug)
+ dbglog("cbcp_recvack: malformed packet");
+ }
}
/* ok peer will do callback */
|
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