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freebsd-dev/contrib/bsnmp/lib/snmpagent.c
Xin LI ecd241b619 Fix bsnmpd remote denial of service vulnerability. 
Reported by:	dinoex
Submitted by:	harti
Security:	FreeBSD-SA-14:01.bsnmpd
Security:	CVE-2014-1452
2014-01-14 18:58:57 +00:00

1068 lines
26 KiB
C
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/*
* 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/snmpagent.c,v 1.20 2005/10/04 11:21:33 brandt_h Exp $
*
* SNMP Agent functions
*/
#include <sys/types.h>
#include <sys/queue.h>
#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdarg.h>
#ifdef HAVE_STDINT_H
#include <stdint.h>
#elif defined(HAVE_INTTYPES_H)
#include <inttypes.h>
#endif
#include <string.h>
#include "asn1.h"
#include "snmp.h"
#include "snmppriv.h"
#include "snmpagent.h"
static void snmp_debug_func(const char *fmt, ...);
void (*snmp_debug)(const char *fmt, ...) = snmp_debug_func;
struct snmp_node *tree;
u_int tree_size;
/*
* Structure to hold dependencies during SET processing
* The last two members of this structure must be the
* dependency visible by the user and the user data.
*/
struct depend {
TAILQ_ENTRY(depend) link;
size_t len; /* size of data part */
snmp_depop_t func;
struct snmp_dependency dep;
#if defined(__GNUC__) && __GNUC__ < 3
u_char data[0];
#else
u_char data[];
#endif
};
TAILQ_HEAD(depend_list, depend);
/*
* Set context
*/
struct context {
struct snmp_context ctx;
struct depend_list dlist;
const struct snmp_node *node[SNMP_MAX_BINDINGS];
struct snmp_scratch scratch[SNMP_MAX_BINDINGS];
struct depend *depend;
};
#define TR(W) (snmp_trace & SNMP_TRACE_##W)
u_int snmp_trace = 0;
static char oidbuf[ASN_OIDSTRLEN];
/*
* Allocate a context
*/
struct snmp_context *
snmp_init_context(void)
{
struct context *context;
if ((context = malloc(sizeof(*context))) == NULL)
return (NULL);
memset(context, 0, sizeof(*context));
TAILQ_INIT(&context->dlist);
return (&context->ctx);
}
/*
* Find a variable for SET/GET and the first GETBULK pass.
* Return the node pointer. If the search fails, set the errp to
* the correct SNMPv2 GET exception code.
*/
static struct snmp_node *
find_node(const struct snmp_value *value, enum snmp_syntax *errp)
{
struct snmp_node *tp;
if (TR(FIND))
snmp_debug("find: searching %s",
asn_oid2str_r(&value->var, oidbuf));
/*
* If we have an exact match (the entry in the table is a
* sub-oid from the variable) we have found what we are for.
* If the table oid is higher than the variable, there is no match.
*/
for (tp = tree; tp < tree + tree_size; tp++) {
if (asn_is_suboid(&tp->oid, &value->var))
goto found;
if (asn_compare_oid(&tp->oid, &value->var) >= 0)
break;
}
if (TR(FIND))
snmp_debug("find: no match");
*errp = SNMP_SYNTAX_NOSUCHOBJECT;
return (NULL);
found:
/* leafs must have a 0 instance identifier */
if (tp->type == SNMP_NODE_LEAF &&
(value->var.len != tp->oid.len + 1 ||
value->var.subs[tp->oid.len] != 0)) {
if (TR(FIND))
snmp_debug("find: bad leaf index");
*errp = SNMP_SYNTAX_NOSUCHINSTANCE;
return (NULL);
}
if (TR(FIND))
snmp_debug("find: found %s",
asn_oid2str_r(&value->var, oidbuf));
return (tp);
}
static struct snmp_node *
find_subnode(const struct snmp_value *value)
{
struct snmp_node *tp;
for (tp = tree; tp < tree + tree_size; tp++) {
if (asn_is_suboid(&value->var, &tp->oid))
return (tp);
}
return (NULL);
}
static void
snmp_pdu_create_response(const struct snmp_pdu *pdu, struct snmp_pdu *resp)
{
memset(resp, 0, sizeof(*resp));
strcpy(resp->community, pdu->community);
resp->version = pdu->version;
resp->type = SNMP_PDU_RESPONSE;
resp->request_id = pdu->request_id;
resp->version = pdu->version;
if (resp->version != SNMP_V3)
return;
memcpy(&resp->engine, &pdu->engine, sizeof(pdu->engine));
memcpy(&resp->user, &pdu->user, sizeof(pdu->user));
snmp_pdu_init_secparams(resp);
resp->identifier = pdu->identifier;
resp->security_model = pdu->security_model;
resp->context_engine_len = pdu->context_engine_len;
memcpy(resp->context_engine, pdu->context_engine,
resp->context_engine_len);
strlcpy(resp->context_name, pdu->context_name,
sizeof(resp->context_name));
}
/*
* Execute a GET operation. The tree is rooted at the global 'root'.
* Build the response PDU on the fly. If the return code is SNMP_RET_ERR
* the pdu error status and index will be set.
*/
enum snmp_ret
snmp_get(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
int ret;
u_int i;
struct snmp_node *tp;
enum snmp_syntax except;
struct context context;
enum asn_err err;
memset(&context, 0, sizeof(context));
context.ctx.data = data;
snmp_pdu_create_response(pdu, resp);
if (snmp_pdu_encode_header(resp_b, resp) != SNMP_CODE_OK)
/* cannot even encode header - very bad */
return (SNMP_RET_IGN);
for (i = 0; i < pdu->nbindings; i++) {
resp->bindings[i].var = pdu->bindings[i].var;
if ((tp = find_node(&pdu->bindings[i], &except)) == NULL) {
if (pdu->version == SNMP_V1) {
if (TR(GET))
snmp_debug("get: nosuchname");
pdu->error_status = SNMP_ERR_NOSUCHNAME;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (TR(GET))
snmp_debug("get: exception %u", except);
resp->bindings[i].syntax = except;
} else {
/* call the action to fetch the value. */
resp->bindings[i].syntax = tp->syntax;
ret = (*tp->op)(&context.ctx, &resp->bindings[i],
tp->oid.len, tp->index, SNMP_OP_GET);
if (TR(GET))
snmp_debug("get: action returns %d", ret);
if (ret == SNMP_ERR_NOSUCHNAME) {
if (pdu->version == SNMP_V1) {
pdu->error_status = SNMP_ERR_NOSUCHNAME;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (TR(GET))
snmp_debug("get: exception noSuchInstance");
resp->bindings[i].syntax = SNMP_SYNTAX_NOSUCHINSTANCE;
} else if (ret != SNMP_ERR_NOERROR) {
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
resp->nbindings++;
err = snmp_binding_encode(resp_b, &resp->bindings[i]);
if (err == ASN_ERR_EOBUF) {
pdu->error_status = SNMP_ERR_TOOBIG;
pdu->error_index = 0;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("get: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
if (snmp_fix_encoding(resp_b, resp) != SNMP_CODE_OK) {
snmp_debug("get: failed to encode PDU");
return (SNMP_RET_ERR);
}
return (SNMP_RET_OK);
}
static struct snmp_node *
next_node(const struct snmp_value *value, int *pnext)
{
struct snmp_node *tp;
if (TR(FIND))
snmp_debug("next: searching %s",
asn_oid2str_r(&value->var, oidbuf));
*pnext = 0;
for (tp = tree; tp < tree + tree_size; tp++) {
if (asn_is_suboid(&tp->oid, &value->var)) {
/* the tree OID is a sub-oid of the requested OID. */
if (tp->type == SNMP_NODE_LEAF) {
if (tp->oid.len == value->var.len) {
/* request for scalar type */
if (TR(FIND))
snmp_debug("next: found scalar %s",
asn_oid2str_r(&tp->oid, oidbuf));
return (tp);
}
/* try next */
} else {
if (TR(FIND))
snmp_debug("next: found column %s",
asn_oid2str_r(&tp->oid, oidbuf));
return (tp);
}
} else if (asn_is_suboid(&value->var, &tp->oid) ||
asn_compare_oid(&tp->oid, &value->var) >= 0) {
if (TR(FIND))
snmp_debug("next: found %s",
asn_oid2str_r(&tp->oid, oidbuf));
*pnext = 1;
return (tp);
}
}
if (TR(FIND))
snmp_debug("next: failed");
return (NULL);
}
static enum snmp_ret
do_getnext(struct context *context, const struct snmp_value *inb,
struct snmp_value *outb, struct snmp_pdu *pdu)
{
const struct snmp_node *tp;
int ret, next;
if ((tp = next_node(inb, &next)) == NULL)
goto eofMib;
/* retain old variable if we are doing a GETNEXT on an exact
* matched leaf only */
if (tp->type == SNMP_NODE_LEAF || next)
outb->var = tp->oid;
else
outb->var = inb->var;
for (;;) {
outb->syntax = tp->syntax;
if (tp->type == SNMP_NODE_LEAF) {
/* make a GET operation */
outb->var.subs[outb->var.len++] = 0;
ret = (*tp->op)(&context->ctx, outb, tp->oid.len,
tp->index, SNMP_OP_GET);
} else {
/* make a GETNEXT */
ret = (*tp->op)(&context->ctx, outb, tp->oid.len,
tp->index, SNMP_OP_GETNEXT);
}
if (ret != SNMP_ERR_NOSUCHNAME) {
/* got something */
if (ret != SNMP_ERR_NOERROR && TR(GETNEXT))
snmp_debug("getnext: %s returns %u",
asn_oid2str(&outb->var), ret);
break;
}
/* object has no data - try next */
if (++tp == tree + tree_size)
break;
if (TR(GETNEXT))
snmp_debug("getnext: no data - avancing to %s",
asn_oid2str(&tp->oid));
outb->var = tp->oid;
}
if (ret == SNMP_ERR_NOSUCHNAME) {
eofMib:
outb->var = inb->var;
if (pdu->version == SNMP_V1) {
pdu->error_status = SNMP_ERR_NOSUCHNAME;
return (SNMP_RET_ERR);
}
outb->syntax = SNMP_SYNTAX_ENDOFMIBVIEW;
} else if (ret != SNMP_ERR_NOERROR) {
pdu->error_status = SNMP_ERR_GENERR;
return (SNMP_RET_ERR);
}
return (SNMP_RET_OK);
}
/*
* Execute a GETNEXT operation. The tree is rooted at the global 'root'.
* Build the response PDU on the fly. The return is:
*/
enum snmp_ret
snmp_getnext(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
struct context context;
u_int i;
enum asn_err err;
enum snmp_ret result;
memset(&context, 0, sizeof(context));
context.ctx.data = data;
snmp_pdu_create_response(pdu, resp);
if (snmp_pdu_encode_header(resp_b, resp))
return (SNMP_RET_IGN);
for (i = 0; i < pdu->nbindings; i++) {
result = do_getnext(&context, &pdu->bindings[i],
&resp->bindings[i], pdu);
if (result != SNMP_RET_OK) {
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (result);
}
resp->nbindings++;
err = snmp_binding_encode(resp_b, &resp->bindings[i]);
if (err == ASN_ERR_EOBUF) {
pdu->error_status = SNMP_ERR_TOOBIG;
pdu->error_index = 0;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("getnext: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
if (snmp_fix_encoding(resp_b, resp) != SNMP_CODE_OK) {
snmp_debug("getnext: failed to encode PDU");
return (SNMP_RET_ERR);
}
return (SNMP_RET_OK);
}
enum snmp_ret
snmp_getbulk(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
struct context context;
u_int i;
int cnt;
u_int non_rep;
int eomib;
enum snmp_ret result;
enum asn_err err;
memset(&context, 0, sizeof(context));
context.ctx.data = data;
snmp_pdu_create_response(pdu, resp);
if (snmp_pdu_encode_header(resp_b, resp) != SNMP_CODE_OK)
/* cannot even encode header - very bad */
return (SNMP_RET_IGN);
if ((non_rep = pdu->error_status) > pdu->nbindings)
non_rep = pdu->nbindings;
/* non-repeaters */
for (i = 0; i < non_rep; i++) {
result = do_getnext(&context, &pdu->bindings[i],
&resp->bindings[resp->nbindings], pdu);
if (result != SNMP_RET_OK) {
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (result);
}
err = snmp_binding_encode(resp_b,
&resp->bindings[resp->nbindings++]);
if (err == ASN_ERR_EOBUF)
goto done;
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("getnext: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
if (non_rep == pdu->nbindings)
goto done;
/* repeates */
for (cnt = 0; cnt < pdu->error_index; cnt++) {
eomib = 1;
for (i = non_rep; i < pdu->nbindings; i++) {
if (resp->nbindings == SNMP_MAX_BINDINGS)
/* PDU is full */
goto done;
if (cnt == 0)
result = do_getnext(&context, &pdu->bindings[i],
&resp->bindings[resp->nbindings], pdu);
else
result = do_getnext(&context,
&resp->bindings[resp->nbindings -
(pdu->nbindings - non_rep)],
&resp->bindings[resp->nbindings], pdu);
if (result != SNMP_RET_OK) {
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (result);
}
if (resp->bindings[resp->nbindings].syntax !=
SNMP_SYNTAX_ENDOFMIBVIEW)
eomib = 0;
err = snmp_binding_encode(resp_b,
&resp->bindings[resp->nbindings++]);
if (err == ASN_ERR_EOBUF)
goto done;
if (err != ASN_ERR_OK) {
if (TR(GET))
snmp_debug("getnext: binding encoding: %u", err);
pdu->error_status = SNMP_ERR_GENERR;
pdu->error_index = i + 1;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
}
if (eomib)
break;
}
done:
if (snmp_fix_encoding(resp_b, resp) != SNMP_CODE_OK) {
snmp_debug("getnext: failed to encode PDU");
return (SNMP_RET_ERR);
}
return (SNMP_RET_OK);
}
/*
* Rollback a SET operation. Failed index is 'i'.
*/
static void
rollback(struct context *context, struct snmp_pdu *pdu, u_int i)
{
struct snmp_value *b;
const struct snmp_node *np;
int ret;
while (i-- > 0) {
b = &pdu->bindings[i];
np = context->node[i];
context->ctx.scratch = &context->scratch[i];
ret = (*np->op)(&context->ctx, b, np->oid.len, np->index,
SNMP_OP_ROLLBACK);
if (ret != SNMP_ERR_NOERROR) {
snmp_error("set: rollback failed (%d) on variable %s "
"index %u", ret, asn_oid2str(&b->var), i);
if (pdu->version != SNMP_V1) {
pdu->error_status = SNMP_ERR_UNDO_FAILED;
pdu->error_index = 0;
}
}
}
}
/*
* Commit dependencies.
*/
int
snmp_dep_commit(struct snmp_context *ctx)
{
struct context *context = (struct context *)ctx;
int ret;
TAILQ_FOREACH(context->depend, &context->dlist, link) {
ctx->dep = &context->depend->dep;
if (TR(SET))
snmp_debug("set: dependency commit %s",
asn_oid2str(&ctx->dep->obj));
ret = context->depend->func(ctx, ctx->dep, SNMP_DEPOP_COMMIT);
if (ret != SNMP_ERR_NOERROR) {
if (TR(SET))
snmp_debug("set: dependency failed %d", ret);
return (ret);
}
}
return (SNMP_ERR_NOERROR);
}
/*
* Rollback dependencies
*/
int
snmp_dep_rollback(struct snmp_context *ctx)
{
struct context *context = (struct context *)ctx;
int ret, ret1;
char objbuf[ASN_OIDSTRLEN];
char idxbuf[ASN_OIDSTRLEN];
ret1 = SNMP_ERR_NOERROR;
while ((context->depend =
TAILQ_PREV(context->depend, depend_list, link)) != NULL) {
ctx->dep = &context->depend->dep;
if (TR(SET))
snmp_debug("set: dependency rollback %s",
asn_oid2str(&ctx->dep->obj));
ret = context->depend->func(ctx, ctx->dep, SNMP_DEPOP_ROLLBACK);
if (ret != SNMP_ERR_NOERROR) {
snmp_debug("set: dep rollback returns %u: %s %s", ret,
asn_oid2str_r(&ctx->dep->obj, objbuf),
asn_oid2str_r(&ctx->dep->idx, idxbuf));
if (ret1 == SNMP_ERR_NOERROR)
ret1 = ret;
}
}
return (ret1);
}
void
snmp_dep_finish(struct snmp_context *ctx)
{
struct context *context = (struct context *)ctx;
struct depend *d;
while ((d = TAILQ_FIRST(&context->dlist)) != NULL) {
ctx->dep = &d->dep;
(void)d->func(ctx, ctx->dep, SNMP_DEPOP_FINISH);
TAILQ_REMOVE(&context->dlist, d, link);
free(d);
}
}
/*
* Do a SET operation.
*/
enum snmp_ret
snmp_set(struct snmp_pdu *pdu, struct asn_buf *resp_b,
struct snmp_pdu *resp, void *data)
{
int ret;
u_int i;
enum asn_err asnerr;
struct context context;
const struct snmp_node *np;
struct snmp_value *b;
enum snmp_syntax except;
memset(&context, 0, sizeof(context));
TAILQ_INIT(&context.dlist);
context.ctx.data = data;
snmp_pdu_create_response(pdu, resp);
if (snmp_pdu_encode_header(resp_b, resp))
return (SNMP_RET_IGN);
/*
* 1. Find all nodes, check that they are writeable and
* that the syntax is ok, copy over the binding to the response.
*/
for (i = 0; i < pdu->nbindings; i++) {
b = &pdu->bindings[i];
if ((np = context.node[i] = find_node(b, &except)) == NULL) {
/* not found altogether or LEAF with wrong index */
if (TR(SET))
snmp_debug("set: node not found %s",
asn_oid2str_r(&b->var, oidbuf));
if (pdu->version == SNMP_V1) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOSUCHNAME;
} else if ((np = find_subnode(b)) != NULL) {
/* 2. intermediate object */
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOT_WRITEABLE;
} else if (except == SNMP_SYNTAX_NOSUCHOBJECT) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NO_ACCESS;
} else {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NO_CREATION;
}
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
/*
* 2. write/createable?
* Can check this for leafs only, because in v2 we have
* to differentiate between NOT_WRITEABLE and NO_CREATION
* and only the action routine for COLUMNS knows, whether
* a column exists.
*/
if (np->type == SNMP_NODE_LEAF &&
!(np->flags & SNMP_NODE_CANSET)) {
if (pdu->version == SNMP_V1) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOSUCHNAME;
} else {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_NOT_WRITEABLE;
}
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
/*
* 3. Ensure the right syntax
*/
if (np->syntax != b->syntax) {
if (pdu->version == SNMP_V1) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_BADVALUE; /* v2: wrongType */
} else {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_WRONG_TYPE;
}
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
/*
* 4. Copy binding
*/
if (snmp_value_copy(&resp->bindings[i], b)) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_GENERR;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
asnerr = snmp_binding_encode(resp_b, &resp->bindings[i]);
if (asnerr == ASN_ERR_EOBUF) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_TOOBIG;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
} else if (asnerr != ASN_ERR_OK) {
pdu->error_index = i + 1;
pdu->error_status = SNMP_ERR_GENERR;
snmp_pdu_free(resp);
return (SNMP_RET_ERR);
}
resp->nbindings++;
}
context.ctx.code = SNMP_RET_OK;
/*
* 2. Call the SET method for each node. If a SET fails, rollback
* everything. Map error codes depending on the version.
*/
for (i = 0; i < pdu->nbindings; i++) {
b = &pdu->bindings[i];
np = context.node[i];
context.ctx.var_index = i + 1;
context.ctx.scratch = &context.scratch[i];
ret = (*np->op)(&context.ctx, b, np->oid.len, np->index,
SNMP_OP_SET);
if (TR(SET))
snmp_debug("set: action %s returns %d", np->name, ret);
if (pdu->version == SNMP_V1) {
switch (ret) {
case SNMP_ERR_NO_ACCESS:
ret = SNMP_ERR_NOSUCHNAME;
break;
case SNMP_ERR_WRONG_TYPE:
/* should no happen */
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_WRONG_LENGTH:
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_WRONG_ENCODING:
/* should not happen */
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_WRONG_VALUE:
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_NO_CREATION:
ret = SNMP_ERR_NOSUCHNAME;
break;
case SNMP_ERR_INCONS_VALUE:
ret = SNMP_ERR_BADVALUE;
break;
case SNMP_ERR_RES_UNAVAIL:
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_COMMIT_FAILED:
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_UNDO_FAILED:
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_AUTH_ERR:
/* should not happen */
ret = SNMP_ERR_GENERR;
break;
case SNMP_ERR_NOT_WRITEABLE:
ret = SNMP_ERR_NOSUCHNAME;
break;
case SNMP_ERR_INCONS_NAME:
ret = SNMP_ERR_BADVALUE;
break;
}
}
if (ret != SNMP_ERR_NOERROR) {
pdu->error_index = i + 1;
pdu->error_status = ret;
rollback(&context, pdu, i);
snmp_pdu_free(resp);
context.ctx.code = SNMP_RET_ERR;
goto errout;
}
}
/*
* 3. Call dependencies
*/
if (TR(SET))
snmp_debug("set: set operations ok");
if ((ret = snmp_dep_commit(&context.ctx)) != SNMP_ERR_NOERROR) {
pdu->error_status = ret;
pdu->error_index = context.ctx.var_index;
if ((ret = snmp_dep_rollback(&context.ctx)) != SNMP_ERR_NOERROR) {
if (pdu->version != SNMP_V1) {
pdu->error_status = SNMP_ERR_UNDO_FAILED;
pdu->error_index = 0;
}
}
rollback(&context, pdu, i);
snmp_pdu_free(resp);
context.ctx.code = SNMP_RET_ERR;
goto errout;
}
/*
* 4. Commit and copy values from the original packet to the response.
* This is not the commit operation from RFC 1905 but rather an
* 'FREE RESOURCES' operation. It shouldn't fail.
*/
if (TR(SET))
snmp_debug("set: commiting");
for (i = 0; i < pdu->nbindings; i++) {
b = &resp->bindings[i];
np = context.node[i];
context.ctx.var_index = i + 1;
context.ctx.scratch = &context.scratch[i];
ret = (*np->op)(&context.ctx, b, np->oid.len, np->index,
SNMP_OP_COMMIT);
if (ret != SNMP_ERR_NOERROR)
snmp_error("set: commit failed (%d) on"
" variable %s index %u", ret,
asn_oid2str_r(&b->var, oidbuf), i);
}
if (snmp_fix_encoding(resp_b, resp) != SNMP_CODE_OK) {
snmp_error("set: fix_encoding failed");
snmp_pdu_free(resp);
context.ctx.code = SNMP_RET_IGN;
}
/*
* Done
*/
errout:
snmp_dep_finish(&context.ctx);
if (TR(SET))
snmp_debug("set: returning %d", context.ctx.code);
return (context.ctx.code);
}
/*
* Lookup a dependency. If it doesn't exist, create one
*/
struct snmp_dependency *
snmp_dep_lookup(struct snmp_context *ctx, const struct asn_oid *obj,
const struct asn_oid *idx, size_t len, snmp_depop_t func)
{
struct context *context;
struct depend *d;
context = (struct context *)(void *)
((char *)ctx - offsetof(struct context, ctx));
if (TR(DEPEND)) {
snmp_debug("depend: looking for %s", asn_oid2str(obj));
if (idx)
snmp_debug("depend: index is %s", asn_oid2str(idx));
}
TAILQ_FOREACH(d, &context->dlist, link)
if (asn_compare_oid(obj, &d->dep.obj) == 0 &&
((idx == NULL && d->dep.idx.len == 0) ||
(idx != NULL && asn_compare_oid(idx, &d->dep.idx) == 0))) {
if(TR(DEPEND))
snmp_debug("depend: found");
return (&d->dep);
}
if(TR(DEPEND))
snmp_debug("depend: creating");
if ((d = malloc(offsetof(struct depend, dep) + len)) == NULL)
return (NULL);
memset(&d->dep, 0, len);
d->dep.obj = *obj;
if (idx == NULL)
d->dep.idx.len = 0;
else
d->dep.idx = *idx;
d->len = len;
d->func = func;
TAILQ_INSERT_TAIL(&context->dlist, d, link);
return (&d->dep);
}
/*
* Make an error response from a PDU. We do this without decoding the
* variable bindings. This means we can sent the junk back to a caller
* that has sent us junk in the first place.
*/
enum snmp_ret
snmp_make_errresp(const struct snmp_pdu *pdu, struct asn_buf *pdu_b,
struct asn_buf *resp_b)
{
u_char type;
asn_len_t len;
struct snmp_pdu resp;
enum asn_err err;
enum snmp_code code;
snmp_pdu_create_response(pdu, &resp);
if ((code = snmp_pdu_decode_header(pdu_b, &resp)) != SNMP_CODE_OK)
return (SNMP_RET_IGN);
if (pdu->version == SNMP_V3) {
if (resp.user.priv_proto != SNMP_PRIV_NOPRIV &&
(asn_get_header(pdu_b, &type, &resp.scoped_len) != ASN_ERR_OK
|| type != ASN_TYPE_OCTETSTRING)) {
snmp_error("cannot decode encrypted pdu");
return (SNMP_RET_IGN);
}
if (asn_get_sequence(pdu_b, &len) != ASN_ERR_OK) {
snmp_error("cannot decode scoped pdu header");
return (SNMP_RET_IGN);
}
len = SNMP_ENGINE_ID_SIZ;
if (asn_get_octetstring(pdu_b, (u_char *)resp.context_engine,
&len) != ASN_ERR_OK) {
snmp_error("cannot decode msg context engine");
return (SNMP_RET_IGN);
}
resp.context_engine_len = len;
len = SNMP_CONTEXT_NAME_SIZ;
if (asn_get_octetstring(pdu_b, (u_char *)resp.context_name,
&len) != ASN_ERR_OK) {
snmp_error("cannot decode msg context name");
return (SNMP_RET_IGN);
}
resp.context_name[len] = '\0';
}
if (asn_get_header(pdu_b, &type, &len) != ASN_ERR_OK) {
snmp_error("cannot get pdu header");
return (SNMP_RET_IGN);
}
if ((type & ~ASN_TYPE_MASK) !=
(ASN_TYPE_CONSTRUCTED | ASN_CLASS_CONTEXT)) {
snmp_error("bad pdu header tag");
return (SNMP_RET_IGN);
}
err = snmp_parse_pdus_hdr(pdu_b, &resp, &len);
if (ASN_ERR_STOPPED(err))
return (SNMP_RET_IGN);
if (pdu_b->asn_len < len)
return (SNMP_RET_IGN);
pdu_b->asn_len = len;
/* now we have the bindings left - construct new message */
resp.error_status = pdu->error_status;
resp.error_index = pdu->error_index;
resp.type = SNMP_PDU_RESPONSE;
code = snmp_pdu_encode_header(resp_b, &resp);
if (code != SNMP_CODE_OK)
return (SNMP_RET_IGN);
if (pdu_b->asn_len > resp_b->asn_len)
/* too short */
return (SNMP_RET_IGN);
(void)memcpy(resp_b->asn_ptr, pdu_b->asn_cptr, pdu_b->asn_len);
resp_b->asn_len -= pdu_b->asn_len;
resp_b->asn_ptr += pdu_b->asn_len;
code = snmp_fix_encoding(resp_b, &resp);
if (code != SNMP_CODE_OK)
return (SNMP_RET_IGN);
return (SNMP_RET_OK);
}
static void
snmp_debug_func(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
vfprintf(stderr, fmt, ap);
va_end(ap);
fprintf(stderr, "\n");
}
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