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Apply patch #9038: SNMP Traps with varbinds

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Applied with modifications. Original patch from Marco Veeneman.
This commit is contained in:
Dirk Ziegelmeier 2016-07-04 21:11:20 +02:00
parent 2fdea8b79b
commit cb5f7859fd
4 changed files with 163 additions and 41 deletions
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31
src/apps/snmp/snmp_msg.c
View File

@ -156,7 +156,6 @@ static err_t snmp_process_set_request(struct snmp_request *request);
static err_t snmp_parse_inbound_frame(struct snmp_request *request);
static err_t snmp_prepare_outbound_frame(struct snmp_request *request);
static err_t snmp_append_outbound_varbind(struct snmp_request *request, struct snmp_varbind* varbind);
static err_t snmp_complete_outbound_frame(struct snmp_request *request);
static void snmp_execute_write_callbacks(struct snmp_request *request);
@ -271,7 +270,7 @@ snmp_process_varbind(struct snmp_request *request, struct snmp_varbind *vb, u8_t
vb->type = (SNMP_ASN1_CONTENTTYPE_PRIMITIVE | SNMP_ASN1_CLASS_CONTEXT | (request->error_status & SNMP_VARBIND_EXCEPTION_MASK));
vb->value_len = 0;
err = snmp_append_outbound_varbind(request, vb);
err = snmp_append_outbound_varbind(&(request->outbound_pbuf_stream), vb);
if (err == ERR_OK) {
/* we stored the exception in varbind -> go on */
request->error_status = SNMP_ERR_NOERROR;
@ -290,7 +289,7 @@ snmp_process_varbind(struct snmp_request *request, struct snmp_varbind *vb, u8_t
vb->value_len = node_instance.get_value(&node_instance, vb->value);
LWIP_ASSERT("SNMP_MAX_VALUE_SIZE is configured too low", (vb->value_len & ~SNMP_GET_VALUE_RAW_DATA) <= SNMP_MAX_VALUE_SIZE);
err = snmp_append_outbound_varbind(request, vb);
err = snmp_append_outbound_varbind(&(request->outbound_pbuf_stream), vb);
if (err == ERR_BUF) {
request->error_status = SNMP_ERR_TOOBIG;
} else if (err != ERR_OK) {
@ -1170,8 +1169,8 @@ snmp_prepare_outbound_frame(struct snmp_request *request)
#define OVB_BUILD_EXEC(code) BUILD_EXEC(code, ERR_ARG)
static err_t
snmp_append_outbound_varbind(struct snmp_request *request, struct snmp_varbind* varbind)
err_t
snmp_append_outbound_varbind(struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind* varbind)
{
struct snmp_asn1_tlv tlv;
u8_t vb_len_len, oid_len_len, value_len_len;
@ -1238,48 +1237,48 @@ snmp_append_outbound_varbind(struct snmp_request *request, struct snmp_varbind*
/* check length already before adding first data because in case of GetBulk,
* data added so far is returned and therefore no partial data shall be added
*/
if ((1 + vb_len_len + vb_value_len) > request->outbound_pbuf_stream.length) {
if ((1 + vb_len_len + vb_value_len) > pbuf_stream->length) {
return ERR_BUF;
}
/* 'VarBind' sequence */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, vb_len_len, vb_value_len);
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(&(request->outbound_pbuf_stream), &tlv) );
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(pbuf_stream, &tlv) );
/* VarBind OID */
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_OBJECT_ID, oid_len_len, oid_value_len);
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(&(request->outbound_pbuf_stream), &tlv) );
OVB_BUILD_EXEC( snmp_asn1_enc_oid(&(request->outbound_pbuf_stream), varbind->oid.id, varbind->oid.len) );
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(pbuf_stream, &tlv) );
OVB_BUILD_EXEC( snmp_asn1_enc_oid(pbuf_stream, varbind->oid.id, varbind->oid.len) );
/* VarBind value */
SNMP_ASN1_SET_TLV_PARAMS(tlv, varbind->type, value_len_len, value_value_len);
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(&(request->outbound_pbuf_stream), &tlv) );
OVB_BUILD_EXEC( snmp_ans1_enc_tlv(pbuf_stream, &tlv) );
if (value_value_len > 0) {
if (varbind->value_len & SNMP_GET_VALUE_RAW_DATA) {
OVB_BUILD_EXEC( snmp_asn1_enc_raw(&(request->outbound_pbuf_stream), (u8_t*)varbind->value, value_value_len) );
OVB_BUILD_EXEC( snmp_asn1_enc_raw(pbuf_stream, (u8_t*)varbind->value, value_value_len) );
} else {
switch (varbind->type)
{
case SNMP_ASN1_TYPE_INTEGER:
OVB_BUILD_EXEC( snmp_asn1_enc_s32t(&(request->outbound_pbuf_stream), value_value_len, *((s32_t*)varbind->value)) );
OVB_BUILD_EXEC( snmp_asn1_enc_s32t(pbuf_stream, value_value_len, *((s32_t*)varbind->value)) );
break;
case SNMP_ASN1_TYPE_COUNTER:
case SNMP_ASN1_TYPE_GAUGE:
case SNMP_ASN1_TYPE_TIMETICKS:
OVB_BUILD_EXEC( snmp_asn1_enc_u32t(&(request->outbound_pbuf_stream), value_value_len, *((u32_t*)varbind->value)) );
OVB_BUILD_EXEC( snmp_asn1_enc_u32t(pbuf_stream, value_value_len, *((u32_t*)varbind->value)) );
break;
case SNMP_ASN1_TYPE_OCTET_STRING:
case SNMP_ASN1_TYPE_IPADDR:
case SNMP_ASN1_TYPE_OPAQUE:
OVB_BUILD_EXEC( snmp_asn1_enc_raw(&(request->outbound_pbuf_stream), (u8_t*)varbind->value, value_value_len) );
OVB_BUILD_EXEC( snmp_asn1_enc_raw(pbuf_stream, (u8_t*)varbind->value, value_value_len) );
value_value_len = varbind->value_len;
break;
case SNMP_ASN1_TYPE_OBJECT_ID:
OVB_BUILD_EXEC( snmp_asn1_enc_oid(&(request->outbound_pbuf_stream), (u32_t*)varbind->value, varbind->value_len / sizeof(u32_t)) );
OVB_BUILD_EXEC( snmp_asn1_enc_oid(pbuf_stream, (u32_t*)varbind->value, varbind->value_len / sizeof(u32_t)) );
break;
case SNMP_ASN1_TYPE_COUNTER64:
OVB_BUILD_EXEC( snmp_asn1_enc_u64t(&(request->outbound_pbuf_stream), value_value_len, (u32_t*)varbind->value) );
OVB_BUILD_EXEC( snmp_asn1_enc_u64t(pbuf_stream, value_value_len, (u32_t*)varbind->value) );
break;
default:
LWIP_ASSERT("Unknown variable type", 0);

14
src/apps/snmp/snmp_msg.h
View File

@ -73,19 +73,6 @@ extern "C" {
#define SNMP_VERSION_2c 1
#define SNMP_VERSION_3 3
struct snmp_varbind
{
/* object identifier */
struct snmp_obj_id oid;
/* value ASN1 type */
u8_t type;
/* object value length */
u16_t value_len;
/* object value */
void *value;
};
struct snmp_varbind_enumerator
{
struct snmp_pbuf_stream pbuf_stream;
@ -183,6 +170,7 @@ extern void* snmp_traps_handle;
void snmp_receive(void *handle, struct pbuf *p, const ip_addr_t *source_ip, u16_t port);
err_t snmp_sendto(void *handle, struct pbuf *p, const ip_addr_t *dst, u16_t port);
u8_t snmp_get_local_ip_for_dst(void* handle, const ip_addr_t *dst, ip_addr_t *result);
err_t snmp_append_outbound_varbind(struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind* varbind);
#ifdef __cplusplus
}

138
src/apps/snmp/snmp_traps.c
View File

@ -48,6 +48,7 @@
#include "lwip/apps/snmp_core.h"
#include "snmp_msg.h"
#include "snmp_asn1.h"
#include "snmp_core_priv.h"
struct snmp_msg_trap
{
@ -71,10 +72,14 @@ struct snmp_msg_trap
u16_t comlen;
/* encoding sequence length */
u16_t seqlen;
/* encoding varbinds sequence length */
u16_t vbseqlen;
};
static u16_t snmp_trap_header_sum(struct snmp_msg_trap *trap);
static u16_t snmp_trap_varbind_sum(struct snmp_msg_trap *trap, struct snmp_varbind *varbinds);
static u16_t snmp_trap_header_sum(struct snmp_msg_trap *trap, u16_t vb_len);
static void snmp_trap_header_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream);
static void snmp_trap_varbind_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind *varbinds);
/** Agent community string for sending traps */
extern const char *snmp_community_trap;
@ -118,12 +123,14 @@ snmp_trap_dst_ip_set(u8_t dst_idx, const ip_addr_t *dst)
}
}
/** Enable/disable authentication traps */
void
snmp_set_auth_traps_enabled(u8_t enable)
{
snmp_auth_traps_enabled = enable;
}
/** Get authentication traps enabled state */
u8_t
snmp_get_auth_traps_enabled(void)
{
@ -146,7 +153,7 @@ snmp_get_auth_traps_enabled(void)
* (sysObjectID) for specific traps.
*/
static err_t
snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_trap, s32_t specific_trap)
snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_trap, s32_t specific_trap, struct snmp_varbind *varbinds)
{
struct snmp_msg_trap trap_msg;
struct snmp_trap_dst *td;
@ -176,7 +183,8 @@ snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_tr
MIB2_COPY_SYSUPTIME_TO(&trap_msg.ts);
/* pass 0, calculate length fields */
tot_len = snmp_trap_header_sum(&trap_msg);
tot_len = snmp_trap_varbind_sum(&trap_msg, varbinds);
tot_len = snmp_trap_header_sum(&trap_msg, tot_len);
/* allocate pbuf(s) */
p = pbuf_alloc(PBUF_TRANSPORT, tot_len, PBUF_RAM);
@ -186,6 +194,7 @@ snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_tr
/* pass 1, encode packet ino the pbuf(s) */
snmp_trap_header_enc(&trap_msg, &pbuf_stream);
snmp_trap_varbind_enc(&trap_msg, &pbuf_stream, varbinds);
snmp_stats.outtraps++;
snmp_stats.outpkts++;
@ -205,25 +214,29 @@ snmp_send_trap(const struct snmp_obj_id *device_enterprise_oid, s32_t generic_tr
return err;
}
/** Send generic SNMP trap */
err_t
snmp_send_trap_generic(s32_t generic_trap)
{
static const struct snmp_obj_id oid = { 7, { 1, 3, 6, 1, 2, 1, 11 } };
return snmp_send_trap(&oid, generic_trap, 0);
return snmp_send_trap(&oid, generic_trap, 0, NULL);
}
/** Send specific SNMP trap with variable bindings */
err_t
snmp_send_trap_specific(s32_t specific_trap)
snmp_send_trap_specific(s32_t specific_trap, struct snmp_varbind *varbinds)
{
return snmp_send_trap(NULL, SNMP_GENTRAP_ENTERPRISE_SPECIFIC, specific_trap);
return snmp_send_trap(NULL, SNMP_GENTRAP_ENTERPRISE_SPECIFIC, specific_trap, varbinds);
}
/** Send coldstart trap */
void
snmp_coldstart_trap(void)
{
snmp_send_trap_generic(SNMP_GENTRAP_COLDSTART);
}
/** Send authentication failure trap (used internally by agent) */
void
snmp_authfail_trap(void)
{
@ -232,6 +245,94 @@ snmp_authfail_trap(void)
}
}
static u16_t
snmp_varbind_len(struct snmp_varbind *varbind)
{
u8_t vb_len_len, oid_len_len, value_len_len;
u16_t vb_value_len, oid_value_len, value_value_len;
/* calculate required lengths */
snmp_asn1_enc_oid_cnt(varbind->oid.id, varbind->oid.len, &oid_value_len);
snmp_asn1_enc_length_cnt(oid_value_len, &oid_len_len);
if (varbind->value_len == 0) {
value_value_len = 0;
} else if (varbind->value_len & SNMP_GET_VALUE_RAW_DATA) {
value_value_len = varbind->value_len & (~SNMP_GET_VALUE_RAW_DATA);
} else {
switch (varbind->type) {
case SNMP_ASN1_TYPE_INTEGER:
if (varbind->value_len != sizeof (s32_t)) {
return ERR_VAL;
}
snmp_asn1_enc_s32t_cnt(*((s32_t*) varbind->value), &value_value_len);
break;
case SNMP_ASN1_TYPE_COUNTER:
case SNMP_ASN1_TYPE_GAUGE:
case SNMP_ASN1_TYPE_TIMETICKS:
if (varbind->value_len != sizeof (u32_t)) {
return ERR_VAL;
}
snmp_asn1_enc_u32t_cnt(*((u32_t*) varbind->value), &value_value_len);
break;
case SNMP_ASN1_TYPE_OCTET_STRING:
case SNMP_ASN1_TYPE_IPADDR:
case SNMP_ASN1_TYPE_OPAQUE:
value_value_len = varbind->value_len;
break;
case SNMP_ASN1_TYPE_NULL:
if (varbind->value_len != 0) {
return ERR_VAL;
}
value_value_len = 0;
break;
case SNMP_ASN1_TYPE_OBJECT_ID:
if ((varbind->value_len & 0x03) != 0) {
return ERR_VAL;
}
snmp_asn1_enc_oid_cnt((u32_t*) varbind->value, varbind->value_len >> 2, &value_value_len);
break;
case SNMP_ASN1_TYPE_COUNTER64:
if (varbind->value_len != (2 * sizeof (u32_t))) {
return ERR_VAL;
}
snmp_asn1_enc_u64t_cnt((u32_t*) varbind->value, &value_value_len);
break;
default:
/* unsupported type */
return ERR_VAL;
}
}
snmp_asn1_enc_length_cnt(value_value_len, &value_len_len);
vb_value_len = 1 + oid_len_len + oid_value_len + 1 + value_len_len + value_value_len;
snmp_asn1_enc_length_cnt(vb_value_len, &vb_len_len);
return 1 + vb_len_len + vb_value_len;
}
static u16_t
snmp_trap_varbind_sum(struct snmp_msg_trap *trap, struct snmp_varbind *varbinds)
{
struct snmp_varbind *varbind;
u16_t tot_len;
u8_t tot_len_len;
tot_len = 0;
varbind = varbinds;
while (varbind != NULL) {
tot_len += snmp_varbind_len(varbind);
varbind = varbind->next;
}
trap->vbseqlen = tot_len;
snmp_asn1_enc_length_cnt(trap->vbseqlen, &tot_len_len);
tot_len += 1 + tot_len_len;
return tot_len;
}
/**
* Sums trap header field lengths from tail to head and
* returns trap_header_lengths for second encoding pass.
@ -241,13 +342,13 @@ snmp_authfail_trap(void)
* @return the required length for encoding the trap header
*/
static u16_t
snmp_trap_header_sum(struct snmp_msg_trap *trap)
snmp_trap_header_sum(struct snmp_msg_trap *trap, u16_t vb_len)
{
u16_t tot_len;
u16_t len;
u8_t lenlen;
tot_len = 0;
tot_len = vb_len;
snmp_asn1_enc_u32t_cnt(trap->ts, &len);
snmp_asn1_enc_length_cnt(len, &lenlen);
@ -296,6 +397,24 @@ snmp_trap_header_sum(struct snmp_msg_trap *trap)
return tot_len;
}
static void
snmp_trap_varbind_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_stream, struct snmp_varbind *varbinds)
{
struct snmp_asn1_tlv tlv;
struct snmp_varbind *varbind;
varbind = varbinds;
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, 0, trap->vbseqlen);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
while(varbind != NULL) {
snmp_append_outbound_varbind(pbuf_stream, varbind);
varbind = varbind->next;
}
}
/**
* Encodes trap header from head to tail.
*/
@ -361,9 +480,6 @@ snmp_trap_header_enc(struct snmp_msg_trap *trap, struct snmp_pbuf_stream *pbuf_s
snmp_asn1_enc_s32t_cnt(trap->ts, &tlv.value_len);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
snmp_asn1_enc_s32t(pbuf_stream, tlv.value_len, trap->ts);
SNMP_ASN1_SET_TLV_PARAMS(tlv, SNMP_ASN1_TYPE_SEQUENCE, 0, 0);
snmp_ans1_enc_tlv(pbuf_stream, &tlv);
}
#endif /* LWIP_SNMP */

21
src/include/lwip/apps/snmp.h
View File

@ -50,6 +50,25 @@ extern "C" {
#include "lwip/err.h"
#include "lwip/apps/snmp_core.h"
/** SNMP variable binding descriptor (publically needed for traps) */
struct snmp_varbind
{
/** pointer to next varbind, NULL for last in list */
struct snmp_varbind *next;
/** pointer to previous varbind, NULL for first in list */
struct snmp_varbind *prev;
/** object identifier */
struct snmp_obj_id oid;
/** value ASN1 type */
u8_t type;
/** object value length */
u16_t value_len;
/** object value */
void *value;
};
/** Agent setup, start listening to port 161. */
void snmp_init(void);
void snmp_set_mibs(const struct snmp_mib **mibs, u8_t num_mibs);
@ -76,7 +95,7 @@ void snmp_trap_dst_ip_set(u8_t dst_idx, const ip_addr_t *dst);
#define SNMP_GENTRAP_ENTERPRISE_SPECIFIC 6
err_t snmp_send_trap_generic(s32_t generic_trap);
err_t snmp_send_trap_specific(s32_t specific_trap);
err_t snmp_send_trap_specific(s32_t specific_trap, struct snmp_varbind *varbinds);
#define SNMP_AUTH_TRAPS_DISABLED 0
#define SNMP_AUTH_TRAPS_ENABLED 1