diff options
| author | Martijn van Duren <martijn@cvs.openbsd.org> | 2019-08-27 06:14:29 +0000 |
|---|---|---|
| committer | Martijn van Duren <martijn@cvs.openbsd.org> | 2019-08-27 06:14:29 +0000 |
| commit | 18615bbab442425d7b3a9e3aac2b180ca2230334 (patch) | |
| tree | d845c85a82e7db974c8bb65beab3b947718ba911 /usr.bin/snmp | |
| parent | 525119fd0f8b4d60c00c50b40650fa36de346258 (diff) | |
Better error reporting on malformed packets.
Diffstat (limited to 'usr.bin/snmp')
| -rw-r--r-- | usr.bin/snmp/snmp.c | 47 |
1 files changed, 36 insertions, 11 deletions
diff --git a/usr.bin/snmp/snmp.c b/usr.bin/snmp/snmp.c index b1bbcb0ab76..7fac77794a7 100644 --- a/usr.bin/snmp/snmp.c +++ b/usr.bin/snmp/snmp.c @@ -1,4 +1,4 @@ -/* $OpenBSD: snmp.c,v 1.1 2019/08/09 06:17:59 martijn Exp $ */ +/* $OpenBSD: snmp.c,v 1.2 2019/08/27 06:14:28 martijn Exp $ */ /* * Copyright (c) 2019 Martijn van Duren <martijn@openbsd.org> @@ -254,26 +254,51 @@ snmp_resolve(struct snmp_agent *agent, struct ber_element *pdu, int reply) if (ret <= 0) goto fail; ber_set_readbuf(&ber, buf, ret); - if ((message = ber_read_elements(&ber, NULL)) == NULL) - goto fail; + if ((message = ber_read_elements(&ber, NULL)) == NULL) { + direction = POLLOUT; + tries--; + continue; + } if (ber_scanf_elements(message, "{ise", &version, &community, - &pdu) != 0) - goto fail; + &pdu) != 0) { + errno = EPROTO; + direction = POLLOUT; + tries--; + continue; + } /* Skip invalid packets; should not happen */ if (version != agent->version || - strcmp(community, agent->community) != 0) + strcmp(community, agent->community) != 0) { + errno = EPROTO; + direction = POLLOUT; + tries--; continue; + } /* Validate pdu format and check request id */ if (ber_scanf_elements(pdu, "{iSSe", &rreqid, &varbind) != 0 || - varbind->be_encoding != BER_TYPE_SEQUENCE) - goto fail; - if (rreqid != reqid) + varbind->be_encoding != BER_TYPE_SEQUENCE) { + errno = EPROTO; + direction = POLLOUT; + tries--; + continue; + } + if (rreqid != reqid) { + errno = EPROTO; + direction = POLLOUT; + tries--; continue; + } for (varbind = varbind->be_sub; varbind != NULL; varbind = varbind->be_next) { - if (ber_scanf_elements(varbind, "{oS}", &oid) != 0) - goto fail; + if (ber_scanf_elements(varbind, "{oS}", &oid) != 0) { + errno = EPROTO; + direction = POLLOUT; + tries--; + break; + } } + if (varbind != NULL) + continue; ber_unlink_elements(message->be_sub->be_next); ber_free_elements(message); |