Started development on the SNMP polling daemon.

1 files changed, 1081 insertions, 0 deletions

diff --git a/src/bsnmp/snmp.c b/src/bsnmp/snmp.c
new file mode 100644
index 0000000..f758262
--- /dev/null
+++ b/src/bsnmp/snmp.c
@@ -0,0 +1,1081 @@
+/*
+ * Copyright (c) 2001-2003
+ *	Fraunhofer Institute for Open Communication Systems (FhG Fokus).
+ *	All rights reserved.
+ *
+ * Author: Harti Brandt <harti@freebsd.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $Begemot: bsnmp/lib/snmp.c,v 1.38 2004/08/06 08:46:53 brandt Exp $
+ *
+ * SNMP
+ */
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <string.h>
+#include <ctype.h>
+#include <netdb.h>
+#include <errno.h>
+
+#include "asn1.h"
+#include "snmp.h"
+#include "snmppriv.h"
+
+static void snmp_error_func(const char *, ...);
+static void snmp_printf_func(const char *, ...);
+
+void (*snmp_error)(const char *, ...) = snmp_error_func;
+void (*snmp_printf)(const char *, ...) = snmp_printf_func;
+
+/*
+ * Get the next variable binding from the list.
+ * ASN errors on the sequence or the OID are always fatal.
+ */
+static enum asn_err
+get_var_binding(struct asn_buf *b, struct snmp_value *binding)
+{
+	u_char type;
+	asn_len_t len, trailer;
+	enum asn_err err;
+
+	if (asn_get_sequence(b, &len) != ASN_ERR_OK) {
+		snmp_error("cannot parse varbind header");
+		return (ASN_ERR_FAILED);
+	}
+
+	/* temporary truncate the length so that the parser does not
+	 * eat up bytes behind the sequence in the case the encoding is
+	 * wrong of inner elements. */
+	trailer = b->asn_len - len;
+	b->asn_len = len;
+
+	if (asn_get_objid(b, &binding->var) != ASN_ERR_OK) {
+		snmp_error("cannot parse binding objid");
+		return (ASN_ERR_FAILED);
+	}
+	if (asn_get_header(b, &type, &len) != ASN_ERR_OK) {
+		snmp_error("cannot parse binding value header");
+		return (ASN_ERR_FAILED);
+	}
+
+	switch (type) {
+
+	  case ASN_TYPE_NULL:
+		binding->syntax = SNMP_SYNTAX_NULL;
+		err = asn_get_null_raw(b, len);
+		break;
+
+	  case ASN_TYPE_INTEGER:
+		binding->syntax = SNMP_SYNTAX_INTEGER;
+		err = asn_get_integer_raw(b, len, &binding->v.integer);
+		break;
+
+	  case ASN_TYPE_OCTETSTRING:
+		binding->syntax = SNMP_SYNTAX_OCTETSTRING;
+		binding->v.octetstring.octets = malloc(len);
+		if (binding->v.octetstring.octets == NULL) {
+			snmp_error("%s", strerror(errno));
+			return (ASN_ERR_FAILED);
+		}
+		binding->v.octetstring.len = len;
+		err = asn_get_octetstring_raw(b, len,
+		    binding->v.octetstring.octets,
+		    &binding->v.octetstring.len);
+		if (ASN_ERR_STOPPED(err)) {
+			free(binding->v.octetstring.octets);
+			binding->v.octetstring.octets = NULL;
+		}
+		break;
+
+	  case ASN_TYPE_OBJID:
+		binding->syntax = SNMP_SYNTAX_OID;
+		err = asn_get_objid_raw(b, len, &binding->v.oid);
+		break;
+
+	  case ASN_CLASS_APPLICATION|ASN_APP_IPADDRESS:
+		binding->syntax = SNMP_SYNTAX_IPADDRESS;
+		err = asn_get_ipaddress_raw(b, len, binding->v.ipaddress);
+		break;
+
+	  case ASN_CLASS_APPLICATION|ASN_APP_TIMETICKS:
+		binding->syntax = SNMP_SYNTAX_TIMETICKS;
+		err = asn_get_uint32_raw(b, len, &binding->v.uint32);
+		break;
+
+	  case ASN_CLASS_APPLICATION|ASN_APP_COUNTER:
+		binding->syntax = SNMP_SYNTAX_COUNTER;
+		err = asn_get_uint32_raw(b, len, &binding->v.uint32);
+		break;
+
+	  case ASN_CLASS_APPLICATION|ASN_APP_GAUGE:
+		binding->syntax = SNMP_SYNTAX_GAUGE;
+		err = asn_get_uint32_raw(b, len, &binding->v.uint32);
+		break;
+
+	  case ASN_CLASS_APPLICATION|ASN_APP_COUNTER64:
+		binding->syntax = SNMP_SYNTAX_COUNTER64;
+		err = asn_get_counter64_raw(b, len, &binding->v.counter64);
+		break;
+
+	  case ASN_CLASS_CONTEXT | ASN_EXCEPT_NOSUCHOBJECT:
+		binding->syntax = SNMP_SYNTAX_NOSUCHOBJECT;
+		err = asn_get_null_raw(b, len);
+		break;
+
+	  case ASN_CLASS_CONTEXT | ASN_EXCEPT_NOSUCHINSTANCE:
+		binding->syntax = SNMP_SYNTAX_NOSUCHINSTANCE;
+		err = asn_get_null_raw(b, len);
+		break;
+
+	  case ASN_CLASS_CONTEXT | ASN_EXCEPT_ENDOFMIBVIEW:
+		binding->syntax = SNMP_SYNTAX_ENDOFMIBVIEW;
+		err = asn_get_null_raw(b, len);
+		break;
+
+	  default:
+		if ((err = asn_skip(b, len)) == ASN_ERR_OK)
+			err = ASN_ERR_TAG;
+		snmp_error("bad binding value type 0x%x", type);
+		break;
+	}
+
+	if (ASN_ERR_STOPPED(err)) {
+		snmp_error("cannot parse binding value");
+		return (err);
+	}
+
+	if (b->asn_len != 0)
+		snmp_error("ignoring junk at end of binding");
+
+	b->asn_len = trailer;
+
+	return (err);
+}
+
+/*
+ * Parse the different PDUs contents. Any ASN error in the outer components
+ * are fatal. Only errors in variable values may be tolerated. If all
+ * components can be parsed it returns either ASN_ERR_OK or the first
+ * error that was found.
+ */
+enum asn_err
+snmp_parse_pdus_hdr(struct asn_buf *b, struct snmp_pdu *pdu, asn_len_t *lenp)
+{
+	if (pdu->type == SNMP_PDU_TRAP) {
+		if (asn_get_objid(b, &pdu->enterprise) != ASN_ERR_OK) {
+			snmp_error("cannot parse trap enterprise");
+			return (ASN_ERR_FAILED);
+		}
+		if (asn_get_ipaddress(b, pdu->agent_addr) != ASN_ERR_OK) {
+			snmp_error("cannot parse trap agent address");
+			return (ASN_ERR_FAILED);
+		}
+		if (asn_get_integer(b, &pdu->generic_trap) != ASN_ERR_OK) {
+			snmp_error("cannot parse 'generic-trap'");
+			return (ASN_ERR_FAILED);
+		}
+		if (asn_get_integer(b, &pdu->specific_trap) != ASN_ERR_OK) {
+			snmp_error("cannot parse 'specific-trap'");
+			return (ASN_ERR_FAILED);
+		}
+		if (asn_get_timeticks(b, &pdu->time_stamp) != ASN_ERR_OK) {
+			snmp_error("cannot parse trap 'time-stamp'");
+			return (ASN_ERR_FAILED);
+		}
+	} else {
+		if (asn_get_integer(b, &pdu->request_id) != ASN_ERR_OK) {
+			snmp_error("cannot parse 'request-id'");
+			return (ASN_ERR_FAILED);
+		}
+		if (asn_get_integer(b, &pdu->error_status) != ASN_ERR_OK) {
+			snmp_error("cannot parse 'error_status'");
+			return (ASN_ERR_FAILED);
+		}
+		if (asn_get_integer(b, &pdu->error_index) != ASN_ERR_OK) {
+			snmp_error("cannot parse 'error_index'");
+			return (ASN_ERR_FAILED);
+		}
+	}
+
+	if (asn_get_sequence(b, lenp) != ASN_ERR_OK) {
+		snmp_error("cannot get varlist header");
+		return (ASN_ERR_FAILED);
+	}
+
+	return (ASN_ERR_OK);
+}
+
+static enum asn_err
+parse_pdus(struct asn_buf *b, struct snmp_pdu *pdu, int32_t *ip)
+{
+	asn_len_t len, trailer;
+	struct snmp_value *v;
+	enum asn_err err, err1;
+
+	err = snmp_parse_pdus_hdr(b, pdu, &len);
+	if (ASN_ERR_STOPPED(err))
+		return (err);
+
+	trailer = b->asn_len - len;
+
+	v = pdu->bindings;
+	err = ASN_ERR_OK;
+	while (b->asn_len != 0) {
+		if (pdu->nbindings == SNMP_MAX_BINDINGS) {
+			snmp_error("too many bindings (> %u) in PDU",
+			    SNMP_MAX_BINDINGS);
+			return (ASN_ERR_FAILED);
+		}
+		err1 = get_var_binding(b, v);
+		if (ASN_ERR_STOPPED(err1))
+			return (ASN_ERR_FAILED);
+		if (err1 != ASN_ERR_OK && err == ASN_ERR_OK) {
+			err = err1;
+			*ip = pdu->nbindings + 1;
+		}
+		pdu->nbindings++;
+		v++;
+	}
+
+	b->asn_len = trailer;
+
+	return (err);
+}
+
+/*
+ * Parse the outer SEQUENCE value. ASN_ERR_TAG means 'bad version'.
+ */
+enum asn_err
+snmp_parse_message_hdr(struct asn_buf *b, struct snmp_pdu *pdu, asn_len_t *lenp)
+{
+	int32_t version;
+	u_char type;
+	u_int comm_len;
+
+	if (asn_get_integer(b, &version) != ASN_ERR_OK) {
+		snmp_error("cannot decode version");
+		return (ASN_ERR_FAILED);
+	}
+
+	if (version == 0) {
+		pdu->version = SNMP_V1;
+	} else if (version == 1) {
+		pdu->version = SNMP_V2c;
+	} else {
+		pdu->version = SNMP_Verr;
+		snmp_error("unsupported SNMP version");
+		return (ASN_ERR_TAG);
+	}
+
+	comm_len = SNMP_COMMUNITY_MAXLEN;
+	if (asn_get_octetstring(b, (u_char *)pdu->community,
+	    &comm_len) != ASN_ERR_OK) {
+		snmp_error("cannot decode community");
+		return (ASN_ERR_FAILED);
+	}
+	pdu->community[comm_len] = '\0';
+
+	if (asn_get_header(b, &type, lenp) != ASN_ERR_OK) {
+		snmp_error("cannot get pdu header");
+		return (ASN_ERR_FAILED);
+	}
+	if ((type & ~ASN_TYPE_MASK) !=
+	    (ASN_TYPE_CONSTRUCTED | ASN_CLASS_CONTEXT)) {
+		snmp_error("bad pdu header tag");
+		return (ASN_ERR_FAILED);
+	}
+	pdu->type = type & ASN_TYPE_MASK;
+
+	switch (pdu->type) {
+
+	  case SNMP_PDU_GET:
+	  case SNMP_PDU_GETNEXT:
+	  case SNMP_PDU_RESPONSE:
+	  case SNMP_PDU_SET:
+		break;
+
+	  case SNMP_PDU_TRAP:
+		if (pdu->version != SNMP_V1) {
+			snmp_error("bad pdu type %u", pdu->type);
+			return (ASN_ERR_FAILED);
+		}
+		break;
+
+	  case SNMP_PDU_GETBULK:
+	  case SNMP_PDU_INFORM:
+	  case SNMP_PDU_TRAP2:
+	  case SNMP_PDU_REPORT:
+		if (pdu->version == SNMP_V1) {
+			snmp_error("bad pdu type %u", pdu->type);
+			return (ASN_ERR_FAILED);
+		}
+		break;
+
+	  default:
+		snmp_error("bad pdu type %u", pdu->type);
+		return (ASN_ERR_FAILED);
+	}
+
+
+	if (*lenp > b->asn_len) {
+		snmp_error("pdu length too long");
+		return (ASN_ERR_FAILED);
+	}
+
+	return (ASN_ERR_OK);
+}
+
+static enum asn_err
+parse_message(struct asn_buf *b, struct snmp_pdu *pdu, int32_t *ip)
+{
+	enum asn_err err;
+	asn_len_t len, trailer;
+
+	err = snmp_parse_message_hdr(b, pdu, &len);
+	if (ASN_ERR_STOPPED(err))
+		return (err);
+
+	trailer = b->asn_len - len;
+	b->asn_len = len;
+
+	err = parse_pdus(b, pdu, ip);
+	if (ASN_ERR_STOPPED(err))
+		return (ASN_ERR_FAILED);
+
+	if (b->asn_len != 0)
+		snmp_error("ignoring trailing junk after pdu");
+
+	b->asn_len = trailer;
+
+	return (err);
+}
+
+/*
+ * Decode the PDU except for the variable bindings itself.
+ * If decoding fails because of a bad binding, but the rest can be
+ * decoded, ip points to the index of the failed variable (errors
+ * OORANGE, BADLEN or BADVERS).
+ */
+enum snmp_code
+snmp_pdu_decode(struct asn_buf *b, struct snmp_pdu *pdu, int32_t *ip)
+{
+	asn_len_t len;
+
+	memset(pdu, 0, sizeof(*pdu));
+
+	if (asn_get_sequence(b, &len) != ASN_ERR_OK) {
+		snmp_error("cannot decode pdu header");
+		return (SNMP_CODE_FAILED);
+	}
+	if (b->asn_len < len) {
+		snmp_error("outer sequence value too short");
+		return (SNMP_CODE_FAILED);
+	}
+	if (b->asn_len != len) {
+		snmp_error("ignoring trailing junk in message");
+		b->asn_len = len;
+	}
+
+	switch (parse_message(b, pdu, ip)) {
+
+	  case ASN_ERR_OK:
+		return (SNMP_CODE_OK);
+
+	  case ASN_ERR_FAILED:
+	  case ASN_ERR_EOBUF:
+		snmp_pdu_free(pdu);
+		return (SNMP_CODE_FAILED);
+
+	  case ASN_ERR_BADLEN:
+		return (SNMP_CODE_BADLEN);
+
+	  case ASN_ERR_RANGE:
+		return (SNMP_CODE_OORANGE);
+
+	  case ASN_ERR_TAG:
+		if (pdu->version == SNMP_Verr)
+			return (SNMP_CODE_BADVERS);
+		else
+			return (SNMP_CODE_BADENC);
+	}
+
+	return (SNMP_CODE_OK);
+}
+
+/*
+ * Check whether what we have is the complete PDU by snooping at the
+ * enclosing structure header. This returns:
+ *   -1		if there are ASN.1 errors
+ *    0		if we need more data
+ *  > 0		the length of this PDU
+ */
+int
+snmp_pdu_snoop(const struct asn_buf *b0)
+{
+	u_int length;
+	asn_len_t len;
+	struct asn_buf b = *b0;
+
+	/* <0x10|0x20> <len> <data...> */
+
+	if (b.asn_len == 0)
+		return (0);
+	if (b.asn_cptr[0] != (ASN_TYPE_SEQUENCE | ASN_TYPE_CONSTRUCTED)) {
+		asn_error(&b, "bad sequence type %u", b.asn_cptr[0]);
+		return (-1);
+	}
+	b.asn_len--;
+	b.asn_cptr++;
+
+	if (b.asn_len == 0)
+		return (0);
+
+	if (*b.asn_cptr & 0x80) {
+		/* long length */
+		length = *b.asn_cptr++ & 0x7f;
+		b.asn_len--;
+		if (length == 0) {
+			asn_error(&b, "indefinite length not supported");
+			return (-1);
+		}
+		if (length > ASN_MAXLENLEN) {
+			asn_error(&b, "long length too long (%u)", length);
+			return (-1);
+		}
+		if (length > b.asn_len)
+			return (0);
+		len = 0;
+		while (length--) {
+			len = (len << 8) | *b.asn_cptr++;
+			b.asn_len--;
+		}
+	} else {
+		len = *b.asn_cptr++;
+		b.asn_len--;
+	}
+
+	if (len > b.asn_len)
+		return (0);
+
+	return (len + b.asn_cptr - b0->asn_cptr);
+}
+
+/*
+ * Encode the SNMP PDU without the variable bindings field.
+ * We do this the rather uneffective way by
+ * moving things around and assuming that the length field will never
+ * use more than 2 bytes.
+ * We need a number of pointers to apply the fixes afterwards.
+ */
+enum snmp_code
+snmp_pdu_encode_header(struct asn_buf *b, struct snmp_pdu *pdu)
+{
+	enum asn_err err;
+
+	if (asn_put_temp_header(b, (ASN_TYPE_SEQUENCE|ASN_TYPE_CONSTRUCTED),
+	    &pdu->outer_ptr) != ASN_ERR_OK)
+		return (SNMP_CODE_FAILED);
+
+	if (pdu->version == SNMP_V1)
+		err = asn_put_integer(b, 0);
+	else if (pdu->version == SNMP_V2c)
+		err = asn_put_integer(b, 1);
+	else
+		return (SNMP_CODE_BADVERS);
+	if (err != ASN_ERR_OK)
+		return (SNMP_CODE_FAILED);
+
+	if (asn_put_octetstring(b, (u_char *)pdu->community,
+	    strlen(pdu->community)) != ASN_ERR_OK)
+		return (SNMP_CODE_FAILED);
+
+	if (asn_put_temp_header(b, (ASN_TYPE_CONSTRUCTED | ASN_CLASS_CONTEXT |
+	    pdu->type), &pdu->pdu_ptr) != ASN_ERR_OK)
+		return (SNMP_CODE_FAILED);
+
+	if (pdu->type == SNMP_PDU_TRAP) {
+		if (pdu->version != SNMP_V1 ||
+		    asn_put_objid(b, &pdu->enterprise) != ASN_ERR_OK ||
+		    asn_put_ipaddress(b, pdu->agent_addr) != ASN_ERR_OK ||
+		    asn_put_integer(b, pdu->generic_trap) != ASN_ERR_OK ||
+		    asn_put_integer(b, pdu->specific_trap) != ASN_ERR_OK ||
+		    asn_put_timeticks(b, pdu->time_stamp) != ASN_ERR_OK)
+			return (SNMP_CODE_FAILED);
+	} else {
+		if (pdu->version == SNMP_V1 && (pdu->type == SNMP_PDU_GETBULK ||
+		    pdu->type == SNMP_PDU_INFORM ||
+		    pdu->type == SNMP_PDU_TRAP2 ||
+		    pdu->type == SNMP_PDU_REPORT))
+			return (SNMP_CODE_FAILED);
+
+		if (asn_put_integer(b, pdu->request_id) != ASN_ERR_OK ||
+		    asn_put_integer(b, pdu->error_status) != ASN_ERR_OK ||
+		    asn_put_integer(b, pdu->error_index) != ASN_ERR_OK)
+			return (SNMP_CODE_FAILED);
+	}
+
+	if (asn_put_temp_header(b, (ASN_TYPE_SEQUENCE|ASN_TYPE_CONSTRUCTED),
+	    &pdu->vars_ptr) != ASN_ERR_OK)
+		return (SNMP_CODE_FAILED);
+
+	return (SNMP_CODE_OK);
+}
+
+enum snmp_code
+snmp_fix_encoding(struct asn_buf *b, const struct snmp_pdu *pdu)
+{
+	if (asn_commit_header(b, pdu->vars_ptr) != ASN_ERR_OK ||
+	    asn_commit_header(b, pdu->pdu_ptr) != ASN_ERR_OK ||
+	    asn_commit_header(b, pdu->outer_ptr) != ASN_ERR_OK)
+		return (SNMP_CODE_FAILED);
+	return (SNMP_CODE_OK);
+}
+
+/*
+ * Encode a binding. Caller must ensure, that the syntax is ok for that version.
+ * Be sure not to cobber b, when something fails.
+ */
+enum asn_err
+snmp_binding_encode(struct asn_buf *b, const struct snmp_value *binding)
+{
+	u_char *ptr;
+	enum asn_err err;
+	struct asn_buf save = *b;
+
+	if ((err = asn_put_temp_header(b, (ASN_TYPE_SEQUENCE |
+	    ASN_TYPE_CONSTRUCTED), &ptr)) != ASN_ERR_OK) {
+		*b = save;
+		return (err);
+	}
+
+	if ((err = asn_put_objid(b, &binding->var)) != ASN_ERR_OK) {
+		*b = save;
+		return (err);
+	}
+
+	switch (binding->syntax) {
+
+	  case SNMP_SYNTAX_NULL:
+		err = asn_put_null(b);
+		break;
+
+	  case SNMP_SYNTAX_INTEGER:
+		err = asn_put_integer(b, binding->v.integer);
+		break;
+
+	  case SNMP_SYNTAX_OCTETSTRING:
+		err = asn_put_octetstring(b, binding->v.octetstring.octets,
+		    binding->v.octetstring.len);
+		break;
+
+	  case SNMP_SYNTAX_OID:
+		err = asn_put_objid(b, &binding->v.oid);
+		break;
+
+	  case SNMP_SYNTAX_IPADDRESS:
+		err = asn_put_ipaddress(b, binding->v.ipaddress);
+		break;
+
+	  case SNMP_SYNTAX_TIMETICKS:
+		err = asn_put_uint32(b, ASN_APP_TIMETICKS, binding->v.uint32);
+		break;
+
+	  case SNMP_SYNTAX_COUNTER:
+		err = asn_put_uint32(b, ASN_APP_COUNTER, binding->v.uint32);
+		break;
+
+	  case SNMP_SYNTAX_GAUGE:
+		err = asn_put_uint32(b, ASN_APP_GAUGE, binding->v.uint32);
+		break;
+
+	  case SNMP_SYNTAX_COUNTER64:
+		err = asn_put_counter64(b, binding->v.counter64);
+		break;
+
+	  case SNMP_SYNTAX_NOSUCHOBJECT:
+		err = asn_put_exception(b, ASN_EXCEPT_NOSUCHOBJECT);
+		break;
+
+	  case SNMP_SYNTAX_NOSUCHINSTANCE:
+		err = asn_put_exception(b, ASN_EXCEPT_NOSUCHINSTANCE);
+		break;
+
+	  case SNMP_SYNTAX_ENDOFMIBVIEW:
+		err = asn_put_exception(b, ASN_EXCEPT_ENDOFMIBVIEW);
+		break;
+	}
+
+	if (err != ASN_ERR_OK) {
+		*b = save;
+		return (err);
+	}
+
+	err = asn_commit_header(b, ptr);
+	if (err != ASN_ERR_OK) {
+		*b = save;
+		return (err);
+	}
+
+	return (ASN_ERR_OK);
+}
+
+/*
+ * Encode an PDU.
+ */
+enum snmp_code
+snmp_pdu_encode(struct snmp_pdu *pdu, struct asn_buf *resp_b)
+{
+	u_int idx;
+	enum snmp_code err;
+
+	if ((err = snmp_pdu_encode_header(resp_b, pdu)) != SNMP_CODE_OK)
+		return (err);
+	for (idx = 0; idx < pdu->nbindings; idx++)
+		if ((err = snmp_binding_encode(resp_b, &pdu->bindings[idx]))
+		    != ASN_ERR_OK)
+			return (SNMP_CODE_FAILED);
+
+	return (snmp_fix_encoding(resp_b, pdu));
+}
+
+static void
+dump_binding(const struct snmp_value *b)
+{
+	u_int i;
+	char buf[ASN_OIDSTRLEN];
+
+	snmp_printf("%s=", asn_oid2str_r(&b->var, buf));
+	switch (b->syntax) {
+
+	  case SNMP_SYNTAX_NULL:
+		snmp_printf("NULL");
+		break;
+
+	  case SNMP_SYNTAX_INTEGER:
+		snmp_printf("INTEGER %d", b->v.integer);
+		break;
+
+	  case SNMP_SYNTAX_OCTETSTRING:
+		snmp_printf("OCTET STRING %lu:", b->v.octetstring.len);
+		for (i = 0; i < b->v.octetstring.len; i++)
+			snmp_printf(" %02x", b->v.octetstring.octets[i]);
+		break;
+
+	  case SNMP_SYNTAX_OID:
+		snmp_printf("OID %s", asn_oid2str_r(&b->v.oid, buf));
+		break;
+
+	  case SNMP_SYNTAX_IPADDRESS:
+		snmp_printf("IPADDRESS %u.%u.%u.%u", b->v.ipaddress[0],
+		    b->v.ipaddress[1], b->v.ipaddress[2], b->v.ipaddress[3]);
+		break;
+
+	  case SNMP_SYNTAX_COUNTER:
+		snmp_printf("COUNTER %u", b->v.uint32);
+		break;
+
+	  case SNMP_SYNTAX_GAUGE:
+		snmp_printf("GAUGE %u", b->v.uint32);
+		break;
+
+	  case SNMP_SYNTAX_TIMETICKS:
+		snmp_printf("TIMETICKS %u", b->v.uint32);
+		break;
+
+	  case SNMP_SYNTAX_COUNTER64:
+		snmp_printf("COUNTER64 %lld", b->v.counter64);
+		break;
+
+	  case SNMP_SYNTAX_NOSUCHOBJECT:
+		snmp_printf("NoSuchObject");
+		break;
+
+	  case SNMP_SYNTAX_NOSUCHINSTANCE:
+		snmp_printf("NoSuchInstance");
+		break;
+
+	  case SNMP_SYNTAX_ENDOFMIBVIEW:
+		snmp_printf("EndOfMibView");
+		break;
+
+	  default:
+		snmp_printf("UNKNOWN SYNTAX %u", b->syntax);
+		break;
+	}
+}
+
+static __inline void
+dump_bindings(const struct snmp_pdu *pdu)
+{
+	u_int i;
+
+	for (i = 0; i < pdu->nbindings; i++) {
+		snmp_printf(" [%u]: ", i);
+		dump_binding(&pdu->bindings[i]);
+		snmp_printf("\n");
+	}
+}
+
+static __inline void
+dump_notrap(const struct snmp_pdu *pdu)
+{
+	snmp_printf(" request_id=%d", pdu->request_id);
+	snmp_printf(" error_status=%d", pdu->error_status);
+	snmp_printf(" error_index=%d\n", pdu->error_index);
+	dump_bindings(pdu);
+}
+
+void
+snmp_pdu_dump(const struct snmp_pdu *pdu)
+{
+	char buf[ASN_OIDSTRLEN];
+	const char *vers;
+	static const char *types[] = {
+		[SNMP_PDU_GET] =	"GET",
+		[SNMP_PDU_GETNEXT] =	"GETNEXT",
+		[SNMP_PDU_RESPONSE] =	"RESPONSE",
+		[SNMP_PDU_SET] =	"SET",
+		[SNMP_PDU_TRAP] =	"TRAPv1",
+		[SNMP_PDU_GETBULK] =	"GETBULK",
+		[SNMP_PDU_INFORM] =	"INFORM",
+		[SNMP_PDU_TRAP2] =	"TRAPv2",
+		[SNMP_PDU_REPORT] =	"REPORT",
+	};
+
+	if (pdu->version == SNMP_V1)
+		vers = "SNMPv1";
+	else if (pdu->version == SNMP_V2c)
+		vers = "SNMPv2c";
+	else
+		vers = "v?";
+
+	switch (pdu->type) {
+	  case SNMP_PDU_TRAP:
+		snmp_printf("%s %s '%s'", types[pdu->type], vers, pdu->community);
+		snmp_printf(" enterprise=%s", asn_oid2str_r(&pdu->enterprise, buf));
+		snmp_printf(" agent_addr=%u.%u.%u.%u", pdu->agent_addr[0],
+		    pdu->agent_addr[1], pdu->agent_addr[2], pdu->agent_addr[3]);
+		snmp_printf(" generic_trap=%d", pdu->generic_trap);
+		snmp_printf(" specific_trap=%d", pdu->specific_trap);
+		snmp_printf(" time-stamp=%u\n", pdu->time_stamp);
+		dump_bindings(pdu);
+		break;
+
+	  case SNMP_PDU_GET:
+	  case SNMP_PDU_GETNEXT:
+	  case SNMP_PDU_RESPONSE:
+	  case SNMP_PDU_SET:
+	  case SNMP_PDU_GETBULK:
+	  case SNMP_PDU_INFORM:
+	  case SNMP_PDU_TRAP2:
+	  case SNMP_PDU_REPORT:
+		snmp_printf("%s %s '%s'", types[pdu->type], vers, pdu->community);
+		dump_notrap(pdu);
+		break;
+
+	  default:
+		snmp_printf("bad pdu type %u\n", pdu->type);
+		break;
+	}
+}
+
+void
+snmp_value_free(struct snmp_value *value)
+{
+	if (value->syntax == SNMP_SYNTAX_OCTETSTRING)
+		free(value->v.octetstring.octets);
+	value->syntax = SNMP_SYNTAX_NULL;
+}
+
+int
+snmp_value_copy(struct snmp_value *to, const struct snmp_value *from)
+{
+	to->var = from->var;
+	to->syntax = from->syntax;
+
+	if (from->syntax == SNMP_SYNTAX_OCTETSTRING) {
+		if ((to->v.octetstring.len = from->v.octetstring.len) == 0)
+			to->v.octetstring.octets = NULL;
+		else {
+			to->v.octetstring.octets = malloc(to->v.octetstring.len);
+			if (to->v.octetstring.octets == NULL)
+				return (-1);
+			(void)memcpy(to->v.octetstring.octets,
+			    from->v.octetstring.octets, to->v.octetstring.len);
+		}
+	} else
+		to->v = from->v;
+	return (0);
+}
+
+void
+snmp_pdu_free(struct snmp_pdu *pdu)
+{
+	u_int i;
+
+	for (i = 0; i < pdu->nbindings; i++)
+		snmp_value_free(&pdu->bindings[i]);
+}
+
+/*
+ * Parse an ASCII SNMP value into the binary form
+ */
+int
+snmp_value_parse(const char *str, enum snmp_syntax syntax, union snmp_values *v)
+{
+	char *end;
+
+	switch (syntax) {
+
+	  case SNMP_SYNTAX_NULL:
+	  case SNMP_SYNTAX_NOSUCHOBJECT:
+	  case SNMP_SYNTAX_NOSUCHINSTANCE:
+	  case SNMP_SYNTAX_ENDOFMIBVIEW:
+		if (*str != '\0')
+			return (-1);
+		return (0);
+
+	  case SNMP_SYNTAX_INTEGER:
+		v->integer = strtoll(str, &end, 0);
+		if (*end != '\0')
+			return (-1);
+		return (0);
+
+	  case SNMP_SYNTAX_OCTETSTRING:
+	    {
+		u_long len;	/* actual length of string */
+		u_long alloc;	/* allocate length of string */
+		u_char *octs;	/* actual octets */
+		u_long oct;	/* actual octet */
+		u_char *nocts;	/* to avoid memory leak */
+		u_char c;	/* actual character */
+
+# define STUFFC(C)							\
+		if (alloc == len) {					\
+			alloc += 100;					\
+			if ((nocts = realloc(octs, alloc)) == NULL) {	\
+				free(octs);				\
+				return (-1);				\
+			}						\
+			octs = nocts;					\
+		}							\
+		octs[len++] = (C);
+
+		len = alloc = 0;
+		octs = NULL;
+
+		if (*str == '"') {
+			str++;
+			while((c = *str++) != '\0') {
+				if (c == '"') {
+					if (*str != '\0') {
+						free(octs);
+						return (-1);
+					}
+					break;
+				}
+				if (c == '\\') {
+					switch (c = *str++) {
+
+					  case '\\':
+						break;
+					  case 'a':
+						c = '\a';
+						break;
+					  case 'b':
+						c = '\b';
+						break;
+					  case 'f':
+						c = '\f';
+						break;
+					  case 'n':
+						c = '\n';
+						break;
+					  case 'r':
+						c = '\r';
+						break;
+					  case 't':
+						c = '\t';
+						break;
+					  case 'v':
+						c = '\v';
+						break;
+					  case 'x':
+						c = 0;
+						if (!isxdigit(*str))
+							break;
+						if (isdigit(*str))
+							c = *str++ - '0';
+						else if (isupper(*str))
+							c = *str++ - 'A' + 10;
+						else
+							c = *str++ - 'a' + 10;
+						if (!isxdigit(*str))
+							break;
+						if (isdigit(*str))
+							c += *str++ - '0';
+						else if (isupper(*str))
+							c += *str++ - 'A' + 10;
+						else
+							c += *str++ - 'a' + 10;
+						break;
+					  case '0': case '1': case '2':
+					  case '3': case '4': case '5':
+					  case '6': case '7':
+						c = *str++ - '0';
+						if (*str < '0' || *str > '7')
+							break;
+						c = *str++ - '0';
+						if (*str < '0' || *str > '7')
+							break;
+						c = *str++ - '0';
+						break;
+					  default:
+						break;
+					}
+				}
+				STUFFC(c);
+			}
+		} else {
+			while (*str != '\0') {
+				oct = strtoul(str, &end, 16);
+				str = end;
+				if (oct > 0xff) {
+					free(octs);
+					return (-1);
+				}
+				STUFFC(oct);
+				if (*str == ':')
+					str++;
+				else if(*str != '\0') {
+					free(octs);
+					return (-1);
+				}
+			}
+		}
+		v->octetstring.octets = octs;
+		v->octetstring.len = len;
+		return (0);
+# undef STUFFC
+	    }
+
+	  case SNMP_SYNTAX_OID:
+	    {
+		u_long subid;
+
+		v->oid.len = 0;
+
+		for (;;) {
+			if (v->oid.len == ASN_MAXOIDLEN)
+				return (-1);
+			subid = strtoul(str, &end, 10);
+			str = end;
+			if (subid > ASN_MAXID)
+				return (-1);
+			v->oid.subs[v->oid.len++] = (asn_subid_t)subid;
+			if (*str == '\0')
+				break;
+			if (*str != '.')
+				return (-1);
+			str++;
+		}
+		return (0);
+	    }
+
+	  case SNMP_SYNTAX_IPADDRESS:
+	    {
+		struct hostent *he;
+		u_long ip[4];
+		int n;
+
+		if (sscanf(str, "%lu.%lu.%lu.%lu%n", &ip[0], &ip[1], &ip[2],
+		    &ip[3], &n) == 4 && (size_t)n == strlen(str) &&
+		    ip[0] <= 0xff && ip[1] <= 0xff &&
+		    ip[2] <= 0xff && ip[3] <= 0xff) {
+			v->ipaddress[0] = (u_char)ip[0];
+			v->ipaddress[1] = (u_char)ip[1];
+			v->ipaddress[2] = (u_char)ip[2];
+			v->ipaddress[3] = (u_char)ip[3];
+			return (0);
+		}
+
+		if ((he = gethostbyname(str)) == NULL)
+			return (-1);
+		if (he->h_addrtype != AF_INET)
+			return (-1);
+
+		v->ipaddress[0] = he->h_addr[0];
+		v->ipaddress[1] = he->h_addr[1];
+		v->ipaddress[2] = he->h_addr[2];
+		v->ipaddress[3] = he->h_addr[3];
+		return (0);
+	    }
+
+	  case SNMP_SYNTAX_COUNTER:
+	  case SNMP_SYNTAX_GAUGE:
+	  case SNMP_SYNTAX_TIMETICKS:
+	    {
+		uint64_t sub;
+
+		sub = strtoull(str, &end, 0);
+		if (*end != '\0' || sub > 0xffffffff)
+			return (-1);
+		v->uint32 = (uint32_t)sub;
+		return (0);
+	    }
+
+	  case SNMP_SYNTAX_COUNTER64:
+		v->counter64 = strtoull(str, &end, 0);
+		if (*end != '\0')
+			return (-1);
+		return (0);
+	}
+	abort();
+}
+
+static void
+snmp_error_func(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	fprintf(stderr, "SNMP: ");
+	vfprintf(stderr, fmt, ap);
+	fprintf(stderr, "\n");
+	va_end(ap);
+}
+
+static void
+snmp_printf_func(const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+}