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Corrected object identifier codec for object ids not starting with .iso.dod (e.g. zeroDotZero (0.0)).

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This commit is contained in:
christiaans 2006-08-07 11:32:44 +00:00
parent a82e02ef15
commit 7eeaf8eaa5
2 changed files with 130 additions and 72 deletions
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150
src/core/snmp/asn1_dec.c
View File

@ -420,6 +420,7 @@ snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid)
{
u16_t plen, base;
u8_t *msg_ptr;
s32_t *oid_ptr;
plen = 0;
while (p != NULL)
@ -431,13 +432,52 @@ snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid)
msg_ptr = p->payload;
msg_ptr += ofs - base;
if ((len > 1) && (*msg_ptr == 0x2B))
oid->len = 0;
oid_ptr = &oid->id[0];
if (len > 0)
{
/* first compressed octet */
if (*msg_ptr == 0x2B)
{
/* (most) common case 1.3 (iso.org) */
*oid_ptr = 1;
oid_ptr++;
*oid_ptr = 3;
oid_ptr++;
}
else if (*msg_ptr < 40)
{
*oid_ptr = 0;
oid_ptr++;
*oid_ptr = *msg_ptr;
oid_ptr++;
}
else if (*msg_ptr < 80)
{
*oid_ptr = 1;
oid_ptr++;
*oid_ptr = (*msg_ptr) - 40;
oid_ptr++;
}
else
{
*oid_ptr = 2;
oid_ptr++;
*oid_ptr = (*msg_ptr) - 80;
oid_ptr++;
}
oid->len = 2;
}
else
{
/* length == 0, zero length (empty list) isn't allowed here.
ISO 8825 (BER) isn't clear about this, but some seem to accept it (why?).
zeroDotZero (0.0) must be at least 06 01 00 */
return ERR_ARG;
}
len--;
if (len > 0)
{
s32_t *oid_ptr;
/* we have compressed 1.3 (iso.org) Z = (X * 40) + Y */
len--;
/* proceed to .dod */
ofs += 1;
if (ofs >= plen)
{
@ -452,51 +492,18 @@ snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid)
/* next octet in same pbuf */
msg_ptr++;
}
oid->len = 0;
oid_ptr = &oid->id[0];
while ((len > 0) && (oid->len < LWIP_SNMP_OBJ_ID_LEN))
}
while ((len > 0) && (oid->len < LWIP_SNMP_OBJ_ID_LEN))
{
/* sub-identifier uses multiple octets */
if (*msg_ptr & 0x80)
{
/* sub-identifier uses multiple octets */
if (*msg_ptr & 0x80)
{
s32_t sub_id = 0;
s32_t sub_id = 0;
while ((*msg_ptr & 0x80) && (len > 1))
{
len--;
sub_id = (sub_id << 7) + (*msg_ptr & ~0x80);
ofs += 1;
if (ofs >= plen)
{
/* next octet in next pbuf */
p = p->next;
if (p == NULL) { return ERR_ARG; }
msg_ptr = p->payload;
plen += p->len;
}
else
{
/* next octet in same pbuf */
msg_ptr++;
}
}
if (!(*msg_ptr & 0x80) && (len > 0))
{
/* last octet sub-identifier */
len--;
sub_id = (sub_id << 7) + *msg_ptr;
*oid_ptr = sub_id;
}
}
else
while ((*msg_ptr & 0x80) && (len > 1))
{
/* !(*msg_ptr & 0x80) sub-identifier uses single octet */
len--;
*oid_ptr = *msg_ptr;
}
if (len > 0)
{
/* remaining oid bytes available ... */
sub_id = (sub_id << 7) + (*msg_ptr & ~0x80);
ofs += 1;
if (ofs >= plen)
{
@ -511,26 +518,53 @@ snmp_asn1_dec_oid(struct pbuf *p, u16_t ofs, u16_t len, struct snmp_obj_id *oid)
/* next octet in same pbuf */
msg_ptr++;
}
}
oid_ptr++;
oid->len++;
}
if (len == 0)
{
/* len == 0, end of oid */
return ERR_OK;
}
if (!(*msg_ptr & 0x80) && (len > 0))
{
/* last octet sub-identifier */
len--;
sub_id = (sub_id << 7) + *msg_ptr;
*oid_ptr = sub_id;
}
}
else
{
/* len > 0, oid->len == LWIP_SNMP_OBJ_ID_LEN or malformed encoding */
return ERR_ARG;
/* !(*msg_ptr & 0x80) sub-identifier uses single octet */
len--;
*oid_ptr = *msg_ptr;
}
if (len > 0)
{
/* remaining oid bytes available ... */
ofs += 1;
if (ofs >= plen)
{
/* next octet in next pbuf */
p = p->next;
if (p == NULL) { return ERR_ARG; }
msg_ptr = p->payload;
plen += p->len;
}
else
{
/* next octet in same pbuf */
msg_ptr++;
}
}
oid_ptr++;
oid->len++;
}
if (len == 0)
{
/* len == 0, end of oid */
return ERR_OK;
}
else
{
/* length <= 1 OR prefix not 1.3 (iso.org) */
/* len > 0, oid->len == LWIP_SNMP_OBJ_ID_LEN or malformed encoding */
return ERR_ARG;
}
}
p = p->next;
}

52
src/core/snmp/asn1_enc.c
View File

@ -143,6 +143,13 @@ snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t *ident, u16_t *octets_needed)
u8_t cnt;
cnt = 0;
if (ident_len > 1)
{
/* compressed prefix in one octet */
cnt++;
ident_len -= 2;
ident += 2;
}
while(ident_len > 0)
{
ident_len--;
@ -157,8 +164,6 @@ snmp_asn1_enc_oid_cnt(u8_t ident_len, s32_t *ident, u16_t *octets_needed)
}
ident++;
}
/* one extra for compressed iso.dod. prefix */
cnt++;
*octets_needed = cnt;
}
@ -445,22 +450,41 @@ snmp_asn1_enc_oid(struct pbuf *p, u16_t ofs, u8_t ident_len, s32_t *ident)
{
msg_ptr = p->payload;
msg_ptr += ofs - base;
/* add compressed prefix .iso.dod */
*msg_ptr = 0x2b;
ofs += 1;
if (ofs >= plen)
if (ident_len > 1)
{
/* next octet in next pbuf */
p = p->next;
if (p == NULL) { return ERR_ARG; }
msg_ptr = p->payload;
plen += p->len;
if ((ident[0] == 1) && (ident[1] == 3))
{
/* compressed (most common) prefix .iso.dod */
*msg_ptr = 0x2b;
}
else
{
/* calculate prefix */
*msg_ptr = (ident[0] * 40) + ident[1];
}
ofs += 1;
if (ofs >= plen)
{
/* next octet in next pbuf */
p = p->next;
if (p == NULL) { return ERR_ARG; }
msg_ptr = p->payload;
plen += p->len;
}
else
{
/* next octet in same pbuf */
msg_ptr++;
}
ident_len -= 2;
ident += 2;
}
else
{
/* next octet in same pbuf */
msg_ptr++;
}
/* ident_len <= 1, at least we need zeroDotZero (0.0) (ident_len == 2) */
return ERR_ARG;
}
while (ident_len > 0)
{
s32_t sub_id;