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8ea2e991fa
bird/proto/snmp/subagent.c
Vojtech Vilimek 8ea2e991fa TMP: work on Get-PDU and GetNext-PDU
2022-09-20 14:28:57 +02:00

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/*
* BIRD -- Simple Network Management Protocol (SNMP)
*
* (c) 2022 Vojtech Vilimek <vojtech.vilimek@nic.cz>
* (c) 2022 CZ.NIC z.s.p.o
*
* Can be freely distributed and used under the terms of the GNU GPL.
*
*/
#include "lib/unaligned.h"
#include "subagent.h"
#include "bgp_mib.h"
/* =============================================================
* Problems
* ------------------------------------------------------------
*
* change of remote ip -> no notification, no update
* same ip, different ports
* distinct VRF (two interfaces with overlapping private addrs)
* posible link-local addresses in LOCAL_IP
*
*/
static int parse_response(struct snmp_proto *p, byte *buf, uint size);
static void header_update_len(byte *buf, u32 len);
static inline uint oid_size(struct oid *o);
static inline uint vb_size(struct agentx_varbind *vb);
static int snmp_stop_ack(sock *sk, uint size);
static void do_response(struct snmp_proto *p, byte *buf, uint size);
static int parse_get_pdu(struct snmp_proto *p, byte *buf, uint size);
static int parse_gets_pdu(struct snmp_proto *p, byte *buf, uint size);
//static void response_fail(struct snmp_proto *p, u16 err_no, u16 index);
static byte *prepare_response(struct snmp_proto *p, byte *buf, uint size);
static void response_err_ind(byte *buf, uint err, uint ind);
static struct oid *bgp_search(struct oid *o_start, struct oid *o_end, struct oid *o_curr);
static struct oid *prefixize(struct snmp_proto *p, struct oid *o, int byte_ord);
static inline byte *find_n_fill(struct snmp_proto *p, struct oid *o, byte *buf, uint size, uint contid, int byte_ord);
static const char * const snmp_errs[] = {
#define SNMP_ERR_SHIFT 256
[AGENTX_RES_OPEN_FAILED - SNMP_ERR_SHIFT] = "Open failed",
[AGENTX_RES_NOT_OPEN - SNMP_ERR_SHIFT] = "Not open",
[AGENTX_RES_INDEX_WRONG_TYPE - SNMP_ERR_SHIFT] = "Index wrong type",
[AGENTX_RES_INDEX_ALREADY_ALLOC - SNMP_ERR_SHIFT] = "Index already allocated",
[AGENTX_RES_INDEX_NONE_AVAIL - SNMP_ERR_SHIFT] = "Index none availlable",
[AGENTX_RES_NOT_ALLOCATED - SNMP_ERR_SHIFT] = "Not allocated",
[AGENTX_RES_UNSUPPORTED_CONTEXT - SNMP_ERR_SHIFT] = "Unsupported contex",
[AGENTX_RES_DUPLICATE_REGISTR - SNMP_ERR_SHIFT] = "Duplicate registration",
[AGENTX_RES_UNKNOWN_REGISTR - SNMP_ERR_SHIFT] = "Unknown registration",
[AGENTX_RES_UNKNOWN_AGENT_CAPS - SNMP_ERR_SHIFT] = "Unknown agent caps",
[AGENTX_RES_PARSE_ERROR - SNMP_ERR_SHIFT] = "Parse error",
[AGENTX_RES_REQUEST_DENIED - SNMP_ERR_SHIFT] = "Request denied",
[AGENTX_RES_PROCESSING_ERR - SNMP_ERR_SHIFT] = "Processing error",
};
/* payload length in bytes */
static inline size_t
pkt_len(byte *buf, byte *pkt)
{
return (pkt - buf) - AGENTX_HEADER_SIZE;
}
static inline size_t
str_size(const char *str)
{
return 4 + BIRD_ALIGN(strlen(str), 4);
}
static byte *
put_str(byte *buf, const char *str)
{
uint len = strlen(str);
uint slen = BIRD_ALIGN(len, 4);
if (len > MAX_STR)
return NULL;
STORE_PTR(buf, len);
memcpy(buf + 4, str, len);
for (uint i = 0; i < slen - len; i++)
buf[len + i] = 0x00; // PADDING
return buf + str_size(str);
}
static byte *
put_blank(byte *buf)
{
STORE_PTR(buf, 0);
return buf + 4;
}
static byte *
put_oid(byte *buf, struct oid *oid)
{
log(L_INFO "testing oid");
for (uint i = 0; i < oid->n_subid; i++)
log(L_INFO "oid id %d: %u", i, oid->ids[i]);
log(L_INFO "put_oid()");
put_u8(buf, oid->n_subid);
log(L_INFO "data %p: %02X", buf, *buf);
put_u8(++buf, oid->prefix);
log(L_INFO "data %p: %02X", buf, *buf);
put_u8(++buf, oid->include);
log(L_INFO "data %p: %02X", buf, *buf);
put_u8(++buf, 0); // PADDING
/* last increment */
++buf;
log(L_INFO "oid head end %p", buf);
/* copy OID data */
#ifdef SNMP_NATIVE
for (uint i = 0; i < oid->n_subid; i++)
*(((u32 *) buf) + i) = oid->ids[i];
#else
put_u32s(buf, oid->ids, oid->n_subid << 2);
#endif
/*
for (uint i = 0; i <= (oid->n_subid << 2) +4 ; i += 4)
log(L_INFO "OID % 3u: %02X %02X %02X %02X", i,
*(buf - 4 + i),
*(buf - 4 + i + 1),
*(buf - 4 + i + 2),
*(buf - 4 + i + 3)
);
*/
return buf + (oid->n_subid << 2);
}
/* paste data at first byte in message
* with 3B of padding
*/
static byte *
paste_fbyte(byte *buf, u8 data)
{
log(L_INFO "paste_fbyte()");
put_u8(buf, data);
put_u24(++buf, 0); // PADDING
return buf + 3;
}
static void
open_pdu(struct snmp_proto *p, struct oid *oid)
{
sock *sk = p->sock;
byte *buf, *pkt;
buf = pkt = sk->tbuf;
uint size = sk->tbsize;
// should be configurable
const char *str = "bird";
//uint pkt_size = 0;
if (size > AGENTX_HEADER_SIZE + oid_size(oid) + str_size(str))
{
log(L_INFO "open_pdu()");
struct agentx_header *h;
SNMP_CREATE(pkt, struct agentx_header, h)
SNMP_B_HEADER(h, AGENTX_OPEN_PDU)
STORE(h->session_id, 1);
STORE(h->transaction_id, 1);
STORE(h->packet_id, 1);
pkt = paste_fbyte(pkt, p->timeout);
pkt = put_oid(pkt, oid);
pkt = put_str(pkt, str);
SNMP_UPDATE(h, pkt_len(buf, pkt));
int ret = sk_send(sk, pkt - buf);
if (ret == 0)
log(L_INFO "sleep");
else if (ret < 0)
log(L_INFO "err %d", ret);
else
log(L_INFO "ok !!! ");
}
else
log(L_INFO "open_pdu() insufficient size, %u <= %u ",
size, AGENTX_HEADER_SIZE + oid_size(oid) + str_size(str));
}
/* index allocate / deallocate pdu * /
static void
de_allocate_pdu(struct snmp_proto *p, struct oid *oid, u8 type)
{
sock *sk = p->sock;
byte *buf, *pkt;
buf = pkt = sk->tbuf;
uint size = sk->tbsize;
if (size > AGENTX_HEADER_SIZE + )
{
log(L_INFO "de_allocate_pdu()");
struct agentx_header *h;
SNMP_CREATE(pkt, struct agentx_header, h);
SNMP_B_HEADER(h, type);
SNMP_SESSION(h,p);
struct agentx_varbind *vb = (struct agentx_varbind *) pkt;
STORE_16(vb->type, AGENTX_OBJECT_ID);
STORE(vb->oid,
}
else
log(L_INFO "de_allocate_pdu(): insufficient size");
}
*/
/* register / unregister pdu */
static void
un_register_pdu(struct snmp_proto *p, struct oid *oid, uint index, uint len, u8 type)
{
sock *sk = p->sock;
byte *buf, *pkt;
buf = pkt = sk->tbuf;
uint size = sk->tbsize;
/* conditional +4 for upper-bound */
if (size > AGENTX_HEADER_SIZE + oid_size(oid) + ((len > 1) ? 4 : 0))
{
log(L_INFO "un_register_pdu()");
struct agentx_un_register_pdu *ur;
SNMP_CREATE(pkt, struct agentx_un_register_pdu, ur);
struct agentx_header *h = &ur->h;
// FIXME correctly set INSTANCE REGISTRATION bit
SNMP_HEADER(h, type, AGENTX_FLAG_INSTANCE_REGISTRATION);
SNMP_SESSION(h, p);
/* do not override timeout */
STORE(ur->timeout, 0);
/* default priority */
STORE(ur->priority, AGENTX_PRIORITY);
STORE(ur->range_subid, (len > 1) ? index : 0);
pkt = put_oid(pkt, oid);
log(L_INFO "pkt - buf : %lu sizeof %u", pkt -buf, AGENTX_HEADER_SIZE);
/* place upper-bound if needed */
if (len > 1)
{
STORE_PTR(pkt, len);
pkt += 4;
}
log("size of pkt: %u", pkt_len(buf,pkt));
SNMP_UPDATE(h, pkt_len(buf, pkt));
for (uint i = 0; i < pkt - buf; i++)
log(L_INFO "%p: %02X", buf+i, *(buf + i));
log(L_INFO "sending (un)register %d", type);
int ret = sk_send(sk, pkt - buf);
if (ret == 0)
log(L_INFO "sleep");
else if (ret < 0)
log(L_INFO "err %d", ret);
else
log(L_INFO "ok !!");
}
else
log(L_INFO "un_register_pdu() insufficient size");
}
/* register pdu */
static void
snmp_register(struct snmp_proto *p, struct oid *oid, uint index, uint len)
{
un_register_pdu(p, oid, index, len, AGENTX_REGISTER_PDU);
}
/* unregister pdu */
static void
snmp_unregister(struct snmp_proto *p, struct oid *oid, uint index, uint len)
{
un_register_pdu(p, oid, index, len, AGENTX_UNREGISTER_PDU);
}
static void
close_pdu(struct snmp_proto *p, u8 reason)
{
sock *sk = p->sock;
byte *buf, *pkt;
buf = pkt = sk->tbuf;
uint size = sk->tbsize;
log(L_INFO "close_pdu() size: %u %c %u", size, (size > AGENTX_HEADER_SIZE + 4)
? '>':'<', AGENTX_HEADER_SIZE);
/* +4B for reason */
if (size > AGENTX_HEADER_SIZE + 4)
{
struct agentx_header *h;
SNMP_CREATE(pkt, struct agentx_header, h)
SNMP_B_HEADER(h, AGENTX_CLOSE_PDU)
SNMP_SESSION(h, p)
pkt = paste_fbyte(pkt, reason);
SNMP_UPDATE(h, pkt_len(buf, pkt));
log(L_INFO "preparing to sk_send()");
int ret = sk_send(sk, pkt - buf);
if (ret == 0)
log(L_INFO "sleep");
else if (ret < 0)
log(L_INFO "err");
else
log(L_INFO, "ok !!");
}
}
static inline void
refresh_ids(struct snmp_proto *p, struct agentx_header *h)
{
int byte_ord = h->flags & AGENTX_NETWORK_BYTE_ORDER;
p->transaction_id = LOAD(h->transaction_id, byte_ord);
p->packet_id = LOAD(h->packet_id, byte_ord);
}
static int
parse_pkt(struct snmp_proto *p, byte *buf, uint size)
{
if (size < AGENTX_HEADER_SIZE)
return 0;
struct agentx_header *h = (void *) buf;
log(L_INFO "parse_pkt got type %u", h->type);
switch (h->type)
{
case AGENTX_RESPONSE_PDU:
return parse_response(p, buf, size);
/*
case AGENTX_GET_PDU:
refresh_ids(p, h);
return parse_get_pdu(p, buf, size);
*/
case AGENTX_GET_PDU:
case AGENTX_GET_NEXT_PDU:
refresh_ids(p, h);
return parse_gets_pdu(p, buf, size);
/* should not happen */
default:
die("unknown packet type %u", h->type);
}
}
static int
parse_response(struct snmp_proto *p, byte *buf, uint size)
{
if (size < sizeof(struct agentx_response))
return 0;
struct agentx_response *r = (void *) buf;
struct agentx_header *h = &r->h;
log(L_INFO "endianity: %s, session %u, transaction: %u", (h->flags & AGENTX_NETWORK_BYTE_ORDER) ? "big end":
"little end", h->session_id, h->transaction_id);
log(L_INFO "sid: %3u\ttid: %3u\tpid: %3u\t", p->session_id, p->transaction_id,
p->packet_id);
log(L_INFO "size %u", h->payload);
log(L_INFO "uptime: %u s", r->uptime);
if (r->err == AGENTX_RES_NO_ERROR)
do_response(p, buf, size);
else
log(L_INFO "an error occured '%s'", snmp_errs[get_u16(&r->err) -
SNMP_ERR_SHIFT]);
return 1;
}
static void
do_response(struct snmp_proto *p, byte *buf, uint size UNUSED)
{
struct agentx_response *r = (void *) buf;
struct agentx_header *h = &r->h;
/* TODO make it asynchronous for better speed */
switch (p->state)
{
case SNMP_INIT:
if (h->flags & AGENTX_NETWORK_BYTE_ORDER)
{
p->session_id = get_u32(&h->session_id);
p->transaction_id = get_u32(&h->transaction_id);
p->packet_id = get_u32(&h->packet_id);
}
else
{
memcpy(&p->session_id, &h->session_id, 12);
}
p->transaction_id++;
log(L_INFO "sending register-pdu");
// register whole BGP4-MIB
u32 arr_bgp[] = {1, 15, 1};
struct oid *o = mb_allocz(p->p.pool, 4 * 4);
put_u8(&o->n_subid, 2);
put_u8(&o->prefix, 2);
memcpy(o->ids, arr_bgp, 2 * 4);
snmp_register(p, o, 0, 1);
put_u8(&o->n_subid, 3);
STORE(o->ids[2], arr_bgp[2]);
snmp_register(p, o, 0, 1);
STORE(o->ids[2], 2);
snmp_register(p, o, 0, 1);
mb_free(o);
u32 arr_with_prefix[] = {1, 15, 3, 1, 1};
struct oid *o2 = mb_allocz(p->p.pool, 10 * 4);
put_u8(&o2->n_subid, 9);
memcpy(o2->ids, arr_with_prefix, 5 * 4);
u32 remote_addr[] = {10, 0, 0, 0};
memcpy(o2->ids + 5, remote_addr, 4 * 4);
STORE(o2->prefix, 2);
// register first line in BGP4-MIB bgpPeerTable
// TODO register all bind bgp connections
snmp_register(p, o2, 9, 24);
mb_free(o2);
p->state = SNMP_REGISTR;
//proto_notify_state(&p->p, PS_UP);
break;
case SNMP_REGISTR:
p->state = SNMP_CONN;
break;
case SNMP_CONN:
break;
default:
die("unkonwn SNMP state");
}
}
static int
parse_get_pdu(struct snmp_proto *p, byte *buf, uint size)
{
log(L_INFO "parse_get_pdu()");
sock *sk = p->sock;
byte *res_pkt, *res = sk->tbuf;
uint rsize = sk->tbsize;
if (size < AGENTX_HEADER_SIZE)
return 0;
log(L_INFO "Get-PDU enough room %p", buf);
struct agentx_header *h = (void *) buf;
ADVANCE(buf, size, AGENTX_HEADER_SIZE);
log(L_INFO "advancing %p cause %u", buf, AGENTX_HEADER_SIZE);
int byte_ord = h->flags & AGENTX_NETWORK_BYTE_ORDER;
byte *pkt = buf;
uint pkt_size = LOAD(h->payload, byte_ord);
log(L_INFO "RX packet size is %u", pkt_size);
uint clen; /* context len */
char *context = NULL;
SNMP_LOAD_CONTEXT(p, h, pkt, context, clen)
log(L_INFO "after context load %p, pkt == buf %d", pkt, pkt == buf);
res_pkt = prepare_response(p, res, rsize);
log(L_INFO "response header created: %p (%u)", res_pkt, res_pkt - res);
/* parsing one search range */
uint ind = 1;
int err = 0;
/* parsed */
while (!err && pkt - buf < pkt_size)
{
struct oid *o_start, *o_end;
o_start = (struct oid *) pkt;
pkt += oid_size(o_start);
o_end = (struct oid *) pkt; // for Get-PDU always null
pkt += oid_size(o_end);
log(L_INFO "sizes o_start %lu o_end %lu", oid_size(o_start),
oid_size(o_end));
log(L_INFO "o_subid: %u o_prefix %u o_include %u ---",
o_start->n_subid, o_start->prefix, o_start->include);
/* currently unsupported non-default context */
res_pkt = find_n_fill(p, o_start, res_pkt, rsize, 0, byte_ord);
/*
struct agentx_varbind *vb_start;
vb_start = (void *) res_pkt;
memcpy(&vb_start->name, o_start, oid_size(o_start));
STORE_16(vb_start->type, AGENTX_INTEGER);
STORE_16(vb_start->pad, 0); // padding zeroing
res_pkt += vb_size(vb_start);
log(L_INFO " vb_size() rpkt %p %u", res_pkt, res_pkt - res);
STORE_PTR(res_pkt, 0x1234ABCD);
log(L_INFO " STORE_PTR int-value rpkt %p %u", res_pkt, res_pkt - res);
res_pkt += 4;
log(L_INFO " shift rpkt %p %u", res_pkt, res_pkt - res);
*/
ind++;
}
struct agentx_header *rh = (void *) res;
SNMP_UPDATE(rh, pkt_len(res, res_pkt));
if (err)
response_err_ind(res, err, ind);
log(L_INFO "res->payload %u (loaded) %u, trying to send: %u",
rh->payload, LOAD(rh->payload, rh->flags & AGENTX_NETWORK_BYTE_ORDER),
res_pkt - res + 4);
int ret = sk_send(sk, res_pkt - res);
log(L_INFO "message sent");
if (ret == 0)
log(L_INFO "sleep");
else if (ret < 0)
log(L_INFO "err no: %d", ret);
else
log(L_INFO "OK !!");
return 1;
}
/* req is request */
static int
parse_gets_pdu(struct snmp_proto *p, byte *req, uint size)
{
log(L_INFO "parse_gets_pdu");
sock *sk = p->sock;
byte *res_pkt, *res = sk->tbuf;
uint rsize = sk->tbsize;
if (size < AGENTX_HEADER_SIZE)
return 0;
struct agentx_header *h = (void *) req;
ADVANCE(req, size, AGENTX_HEADER_SIZE);
log(L_INFO "advancing %p cause header", req);
byte *pkt = req;
int byte_ord = h->flags & AGENTX_NETWORK_BYTE_ORDER;
uint pkt_size = LOAD(h->payload, byte_ord);
uint clen;
char *context;
SNMP_LOAD_CONTEXT(p, h, req, context, clen);
res_pkt = prepare_response(p, res, rsize);
uint ind = 1;
int err = 0;
while (!err && pkt - req < pkt_size)
{
struct oid *o_start, *o_end;
o_start = (struct oid *) pkt;
pkt += oid_size(o_start);
o_end = (struct oid *) pkt;
pkt += oid_size(o_end);
// TODO normalize OID to prefix form
/* advertised size of oid is greater then size of message */
if (oid_size(o_start) > size || oid_size(o_end) > size)
{
err = -1; /* parse error too big n_subid */
continue;
}
switch (h->type)
{
case AGENTX_GET_PDU:
res_pkt = find_n_fill(p, o_start, res_pkt, rsize, 0, byte_ord);
break;
case AGENTX_GET_NEXT_PDU:
o_start = bgp_search(o_start, o_end, NULL);
if (o_start)
res_pkt = find_n_fill(p, o_start, res_pkt, rsize, 0, byte_ord);
else
{
err = -2;
continue;
}
break;
case AGENTX_GET_BULK_PDU:
{
struct oid *o_curr = NULL;
/* TODO add res packet size limiting logic */
while ((o_curr = bgp_search(o_start, o_end, o_curr)) != NULL)
{
res_pkt = find_n_fill(p, o_start, res_pkt, rsize, 0, byte_ord);
}
/* no item found */
if (res_pkt == res + sizeof(struct agentx_response))
{
err = -2;
continue;
}
break;
}
}
ind++;
}
switch (err)
{
case 0:
response_err_ind(req, AGENTX_RES_NO_ERROR, 0);
err = 1;
break;
case -1:
response_err_ind(req, AGENTX_RES_PARSE_ERROR, ind);
break;
/* no item found - could it happen? */
case -2:
response_err_ind(req, AGENTX_RES_GEN_ERROR, ind);
break;
}
struct agentx_header *rh = (void *) res;
SNMP_UPDATE(rh, pkt_len(res, res_pkt));
int ret = sk_send(sk, res_pkt - res);
log(L_INFO "message sent");
if (ret == 0)
log(L_INFO "sleep");
else if (ret < 0)
log(L_INFO "err no: %d", ret);
else
log("OK ! !!");
return err;
}
static void
header_update_len(byte *buf, u32 len)
{
struct agentx_header *h = (void *) buf;
put_u32(&h->payload, len);
log(L_INFO "header_update_len() %d 0x%02X 0x%02X 0x%02X 0x%02X", len, *((unsigned char
*) &h->payload), *(((unsigned char *) &h->payload) + 1), *(((unsigned char *)
&h->payload) + 2), *(((unsigned char *) &h->payload) + 3));
}
void
snmp_start_subagent(struct snmp_proto *p)
{
log(L_INFO "snmp_start_subagent() starting subagent");
/* blank oid means unsupported */
struct oid *o = mb_allocz(p->p.pool, sizeof(struct oid));
open_pdu(p, o);
mb_free(o);
}
void
snmp_stop_subagent(struct snmp_proto *p)
{
log(L_INFO "snmp_stop_subagent()");
sock *sk = p->sock;
if (p->state == SNMP_CONN)
{
close_pdu(p, AGENTX_CLOSE_SHUTDOWN);
sk->rx_hook = snmp_stop_ack;
}
}
static inline uint
oid_size(struct oid *o)
{
/* faster multipication by 4 */
return 4 + (o->n_subid << 2);
}
static inline uint
vb_size(struct agentx_varbind *vb)
{
/* +4B for type and pad */
return oid_size(&vb->name) + 4;
}
int
snmp_rx(sock *sk, uint size)
{
log(L_INFO "snmp_rx()");
struct snmp_proto *p = sk->data;
byte *pkt = sk->rbuf;
// 1 means all done; 0 means to be continued
return parse_pkt(p, pkt, size);
/*
while (end >= pkt + AGENTX_HEADER_SIZE)
{
parse_header(p);
parse_pkt(p, );
}
*/
}
/* ping pdu */
void
snmp_ping(struct snmp_proto *p)
{
/* this does not support non-default context */
sock *sk = p->sock;
byte *pkt = sk->tbuf;
uint size = sk->tbsize;
if (size > AGENTX_HEADER_SIZE)
{
log(L_INFO "ping_pdu()");
struct agentx_header *h;
log("before dead %p", pkt );
SNMP_CREATE(pkt, struct agentx_header, h);
SNMP_B_HEADER(h, AGENTX_PING_PDU);
SNMP_SESSION(h, p);
/* sending only header => pkt - buf */
int ret = sk_send(sk, AGENTX_HEADER_SIZE);
if (ret == 0)
log(L_INFO "sleep");
else if (ret < 0)
log(L_INFO "err %d", ret);
else
log("ok ! !");
}
else
log(L_INFO "ping_pdu() insufficient size");
}
static int
snmp_stop_ack(sock *sk, uint size)
{
struct snmp_proto *p = sk->data;
byte *buf = sk->rbuf;
if (size < AGENTX_HEADER_SIZE)
return 0;
if (parse_response(p, buf, size))
{
p->p.disabled = 1;
proto_notify_state(&p->p, PS_DOWN);
sk->tx_hook = NULL;
sk->rx_hook = NULL;
}
/* all done */
return 0;
}
/*
void
snmp_agent_reconfigure(void)
{
}
*/
static int
compare(struct oid *left, struct oid *right)
{
if (left->prefix < right->prefix)
return -1;
else if (left->prefix > right->prefix)
return 1;
for (int i = 0; i < MIN(left->n_subid, right->n_subid); i++)
{
if (left->ids[i] < right->ids[i])
return -1;
else if (left->ids[i] > right->ids[i])
return 1;
}
return 0;
}
static inline int
is_bgp4_mib_prefix(struct oid *o)
{
if (o->prefix == 2 && o->ids[0] == 15)
return 1;
else
return 0;
}
static struct oid *
bgp_search(struct oid *o_start, struct oid *e_end, struct oid *o_curr)
{
if (o_start->include);
// if valid o_start
// search o_start.0 (resp. o_start.1)
return o_start;
}
static byte *
find_bgp_one(struct bgp_proto *bp, struct oid *o, byte *pkt, uint size, uint contid)
{
struct bgp_conn *b_conn = bp->conn;
struct bgp_conn *b_in = &bp->incoming_conn;
struct bgp_conn *b_out = &bp->outgoing_conn;
struct bgp_stats *b_stats = &bp->stats;
const struct bgp_config *b_conf = bp->cf;
uint b_state;
if (b_conn)
b_state = b_conn->state;
else if (MAX(b_in->state, b_out->state) == BS_CLOSE &&
MIN(b_in->state, b_out->state) != BS_CLOSE)
b_state = MIN(b_in->state, b_out->state);
/* BS_CLOSE is unsupported by BGP4-MIB */
else if (MIN(b_in->state, b_out->state) == BS_CLOSE)
b_state = BS_IDLE;
else
b_state = MAX(b_in->state, b_out->state);
struct agentx_varbind *vb = (void *) pkt;
pkt += vb_size(vb);
switch (o->ids[4])
{
case SNMP_BGP_IDENTIFIER:
if (b_state == BS_OPENCONFIRM || b_state == BS_ESTABLISHED)
{
STORE_PTR(pkt, ipa_to_u32(bp->remote_ip));
BGP_DATA(vb, AGENTX_IP_ADDRESS, pkt);
}
else
{
STORE_PTR(pkt, ipa_to_u32(IPA_NONE));
BGP_DATA(vb, AGENTX_IP_ADDRESS, pkt);
}
break;
case SNMP_BGP_STATE:
STORE_PTR(pkt, b_state);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_ADMIN_STATUS:
if (((struct proto *) bp)->disabled)
STORE_PTR(pkt, AGENTX_ADMIN_STOP);
else
STORE_PTR(pkt, AGENTX_ADMIN_START);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_VERSION:
if (b_state == BS_OPENCONFIRM || b_state == BS_ESTABLISHED)
STORE_PTR(pkt, 4);
else
STORE_PTR(pkt, 0);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_LOCAL_ADDR:
// TODO XXX bp->link_addr & zero local_ip
STORE_PTR(pkt, ipa_to_u32(bp->local_ip));
BGP_DATA(vb, AGENTX_IP_ADDRESS, pkt);
break;
case SNMP_BGP_LOCAL_PORT:
STORE_PTR(pkt, b_conf->local_port);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_REMOTE_ADDR:
STORE_PTR(pkt, ipa_to_u32(bp->remote_ip));
BGP_DATA(vb, AGENTX_IP_ADDRESS, pkt);
break;
case SNMP_BGP_REMOTE_PORT:
STORE_PTR(pkt, b_conf->remote_port);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_REMOTE_AS:
STORE_PTR(pkt, bp->remote_as);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
/* IN UPDATES */
case SNMP_BGP_RX_UPDATES:
STORE_PTR(pkt, b_stats->rx_updates);
BGP_DATA(vb, AGENTX_COUNTER_32, pkt);
break;
/* OUT UPDATES */
case SNMP_BGP_TX_UPDATES:
STORE_PTR(pkt, b_stats->tx_updates);
BGP_DATA(vb, AGENTX_COUNTER_32, pkt);
break;
/* IN MESSAGES */
case SNMP_BGP_RX_MESSAGES:
STORE_PTR(pkt, b_stats->rx_messages);
BGP_DATA(vb, AGENTX_COUNTER_32, pkt);
break;
/* OUT MESSAGES */
case SNMP_BGP_TX_MESSAGES:
STORE_PTR(pkt, b_stats->tx_messages);
BGP_DATA(vb, AGENTX_COUNTER_32, pkt);
break;
case SNMP_BGP_LAST_ERROR:
STORE_PTR(pkt, 2);
pkt += 4;
/* force network order */
put_u32(pkt,
(bp->last_error_code << 8 | bp->last_error_code << 48) & 0xFFFF0000);
/* real size is 8 but we already shifted the pkt by 4 */
BGP_DATA(vb, AGENTX_OCTET_STRING, pkt);
break;
case SNMP_BGP_FSM_TRANSITIONS:
STORE_PTR(pkt, b_stats->fsm_established_transitions);
BGP_DATA(vb, AGENTX_COUNTER_32, pkt);
break;
case SNMP_BGP_RETRY_INTERVAL:
STORE_PTR(pkt, b_conf->connect_retry_time);
BGP_DATA(vb, AGENTX_COUNTER_32, pkt);
break;
case SNMP_BGP_HOLD_TIME:
if (b_conn && b_conf->hold_time)
STORE_PTR(pkt, b_conn->hold_time);
else
STORE_PTR(pkt, 0);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_KEEPALIVE:
if (b_conn && b_conf->keepalive_time)
STORE_PTR(pkt, b_conn->keepalive_time);
else
STORE_PTR(pkt, 0);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_HOLD_TIME_CONFIGURED:
STORE_PTR(pkt, b_conf->hold_time);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_KEEPALIVE_CONFIGURED:
STORE_PTR(pkt, b_conf->keepalive_time);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
/* UNSUPPORTED */
/* TODO XXX forbiden value 0 */
case SNMP_BGP_ORIGINATION_INTERVAL:
case SNMP_BGP_MIN_ROUTE_ADVERTISEMENT:
STORE_PTR(pkt, 0);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case SNMP_BGP_FSM_ESTABLISHED_TIME:
case SNMP_BGP_IN_UPDATE_ELAPSED_TIME:
vb->type = AGENTX_NO_SUCH_OBJECT;
/* pkt += 0; no data */
break;
/* no default */
}
return pkt;
}
/* contid - context identification number */
static byte *
snmp_bgp_record(struct snmp_proto *p, struct oid *o, byte *buf, uint size, uint contid)
{
struct agentx_varbind *vb = (void *) buf;
byte *pkt = buf + vb_size(vb);
switch (o->ids[2])
{
case BGP4_MIB_VERSION:
STORE_PTR(pkt, 1); // string len
pkt += 4;
STORE_PTR(pkt, BGP4_VERSIONS);
/* real size is 8 but we already shifted the pkt by 4 */
BGP_DATA(vb, AGENTX_OCTET_STRING, pkt);
break;
case BGP4_MIB_LOCAL_AS:
// XXX local as to use
STORE_PTR(pkt, p->local_as);
BGP_DATA(vb, AGENTX_INTEGER, pkt);
break;
case BGP4_PEER_TABLE:
/* end part of .1.3.6.1.2.1.15.3.1.x.a.b.c.d */
if (o->n_subid < 9 || o->ids[3] != BGP4_PEER_ENTRY
|| o->ids[4] == 0 || o->ids[4] > 24)
{
vb->type = AGENTX_NO_SUCH_OBJECT;
return buf + vb_size(vb);
}
// TODO enumerate range requests
ip_addr addr = ipa_build4(o->ids[5], o->ids[6], o->ids[7], o->ids[8]);
struct snmp_bgp_peer *pe =
HASH_FIND(p->bgp_hash, SNMP_HASH, addr);
struct bgp_proto *bp = NULL;
if (pe && pe->bond->proto->proto &&
ipa_equal(addr,
((struct bgp_proto *) pe->bond->proto->proto)->remote_ip))
{
bp = (void *) pe->bond->proto->proto;
}
/* IF WE CONSIDER CHANGES OF REMOTE IP
else
{
struct snmp_bond *b;
WALK_LIST(b, p->bgp_entries)
if (b->proto->proto &&
ipa_equal(((struct bgp_proto *) b->proto->proto)->remote_ip, addr))
bp = (struct bgp_proto *) b->proto->proto;
}
*/
if (!bp)
{
vb->type = AGENTX_NO_SUCH_OBJECT;
/* pkt += 0; no data */
return pkt;
}
return find_bgp_one(bp, o, buf, size, contid);
break;
default:
vb->type = AGENTX_NO_SUCH_OBJECT;
/* pkt += 0; no data */
break;
}
return pkt;
}
static byte *
find_ospf_record(struct snmp_proto *p, struct oid *o, byte *buf, uint size)
{
// TODO XXX
return NULL;
}
static byte *
unsupported_oid(struct snmp_proto *p, struct oid *o, byte *buf, uint size, uint contid)
{
struct agentx_varbind *vb = (void *) buf;
vb->type = AGENTX_NO_SUCH_OBJECT;
return buf + vb_size(vb);
}
static inline byte *
find_prefixed(struct snmp_proto *p, struct oid *o, byte *buf, uint size, uint contid)
{
struct agentx_varbind *vb = (void *) buf;
memcpy(&vb->name, o, oid_size(o));
/* SNMPv2 mgmt mib-2 */
if (o->n_subid < 2 || (o->prefix != 2 && o->ids[0] != 1))
{
vb->type = AGENTX_NO_SUCH_OBJECT;
return buf + vb_size(vb);
}
switch (o->ids[1])
{
case SNMP_BGP4_MIB:
if (snmp_bgp_is_supported(o))
return snmp_bgp_record(p, o, buf, size, contid);
else
return unsupported_oid(p, o, buf, size, contid);
case SNMP_OSPFv3_MIB:
return unsupported_oid(p, o, buf, size, contid);
//return find_ospf_record(p, o, buf, size);
default:
return unsupported_oid(p, o, buf, size, contid);
log(L_INFO "unsupported oid");
break;
}
}
/* tests if there is present canonical "internet" prefix .1.3.6.1
and if so it shortens the oid to the ``prefix'' form */
static int
prefixize_in_place(struct oid *o, int byte_ord)
{
const u32 prefix[] = {1, 3, 6, 1};
/* NETWORK_BYTE_ORDER */
if (byte_ord)
/* prefix len == 4 */
for (uint i = 0; i < 4; i++)
if (get_u32(&o->ids[i]) != prefix[i]) return 0;
else
/* prefix len == 4 */
for (uint i = 0; i < 4; i++)
if (o->ids[i] != prefix[i]) return 0;
o->n_subid -= 5;
o->prefix = o->ids[4];
/* n_subid contains number of elements, not bytes */
memmove(&o->ids, &o->ids[5], o->n_subid << 2);
return 1;
}
static struct oid *
prefixize(struct snmp_proto *p, struct oid *o, int byte_ord)
{
const u32 prefix[] = {1, 3, 6, 1};
if (o->n_subid < 5)
return NULL;
for (int i = 0; i < 4; i++)
if (LOAD(o->ids[i], byte_ord) != prefix[i])
return NULL;
struct oid *new = mb_alloc(p->p.pool, sizeof(struct oid) + MAX((o->n_subid - 5) * 4, 0));
memcpy(new, o, sizeof(struct oid));
new->n_subid = o->n_subid - 5;
if (o->ids[4] < 256)
new->prefix = o->ids[4];
else return NULL;
memcpy(&new->ids, &o->ids[5], new->n_subid * 4);
return new;
}
static inline byte *
find_n_fill(struct snmp_proto *p, struct oid *o, byte *buf, uint size, uint contid, int byte_ord)
{
struct oid *new;
if (!o->prefix && (new = prefixize(p, o, byte_ord)) != NULL)
find_prefixed(p, new, buf, size, contid);
else if (o->prefix)
find_prefixed(p, o, buf, size, contid);
else
// TODO handle unprefixable oids
return NULL;
}
static byte *
prepare_response(struct snmp_proto *p, byte *buf, uint size)
{
log(L_INFO "prepare_response()");
if (size < sizeof(struct agentx_response))
return NULL;
struct agentx_response *r = (void *) buf;
struct agentx_header *h = &r->h;
SNMP_B_HEADER(h, AGENTX_RESPONSE_PDU)
SNMP_SESSION(h, p)
/* protocol doesn't care about subagent upTime */
STORE(r->uptime, 0);
STORE_16(r->err, AGENTX_RES_NO_ERROR);
STORE_16(r->index, 0);
buf += sizeof(struct agentx_response);
return buf;
}
static void
response_err_ind(byte *buf, uint err, uint ind)
{
log(L_INFO "reponse_err_ind()");
struct agentx_response *res = (void *) buf;
res->err = err;
res->index = ind;
}
#undef SNMP_ERR_SHIFT
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