/*
*===========================================================================
* ipcom_buffer_len
*===========================================================================
* Description: Returns the number of bytes of data in the buffer.
* Parameters:
* Returns:
*
*/
IP_PUBLIC Ip_u32
ipcom_buffer_len(Ipcom_buffer *buffer)
{
IPCOM_LOG4(DEBUG2,
"ipcom_buffer_len :: buf=%x, len=%d, end=%d, offset=%d",
buffer, buffer->end - buffer->offset, buffer->end, buffer->offset);
return buffer->end - buffer->offset;
}
/*
*===========================================================================
* ipnet_nat_proxy_dns_transaction_timeout
*===========================================================================
* Description: Timeout handler for DNS transactions timeouts
* Parameters: cookie - a cookie that is set when the timeout is added.
* Returns: nothing.
*/
IP_STATIC void
ipnet_nat_proxy_dns_transaction_timeout(void *cookie)
{
Ipnet_nat_dns_transaction *trans = cookie;
IPCOM_LOG4(DEBUG, "ipnet_nat_proxy_dns_transaction_timeout() :: expired transaction:"
"id=%d port=%d addr=0x%08x type=%d",
trans->id, trans->srcport, trans->dstaddr, trans->type);
ipcom_list_remove(&trans->list);
ipcom_free(trans);
}
/*
*===========================================================================
* ipcom_buffer_decr_cap
*===========================================================================
* Description:
* Parameters:
* Returns:
*
*/
IP_PUBLIC Ip_err
ipcom_buffer_decr_cap(Ipcom_buffer *buffer, Ip_u32 len)
{
ip_assert( len <= ipcom_buffer_capacity(buffer) );
if(len > ipcom_buffer_capacity(buffer))
return IPCOM_ERR_FAILED;
IPCOM_LOG4(DEBUG2,
"ipcom_buffer_decr_cap :: buf=%x, len=%d, end=%d, offset=%d",
buffer, len, buffer->end, buffer->offset);
buffer->end += len;
return IPCOM_SUCCESS;
}
/*
*===========================================================================
* ipcom_buffer_consume_end
*===========================================================================
* Description: Consumes the given number of bytes from the end of the buffer.
* Parameters:
* Returns:
*
*/
IP_PUBLIC Ip_err
ipcom_buffer_consume_end(Ipcom_buffer *buffer, Ip_u32 bytes)
{
ip_assert( bytes <= (buffer->end - buffer->offset) );
if(bytes > (buffer->end - buffer->offset))
return IPCOM_ERR_FAILED;
IPCOM_LOG4(DEBUG2,
"ipcom_buffer_consume_end :: buf=%x, bytes=%d, end=%d, offset=%d",
buffer, bytes, buffer->end, buffer->offset);
buffer->end -= bytes;
return IPCOM_SUCCESS;
}
/*
*===========================================================================
* ipnet_nat_proxy_dns_parse_answers
*===========================================================================
* Description: Parses and modifies DNS answers in a DNS packet.
* Parameters: buf - pointer to buffer with the DNS questions.
* buflen - length of buffer with DNS questions.
* offset - offset in the buffer where the DNS questions begin.
* newlen - pointer to the length of the message if modified.
* dns_hdr - pointer to the DNS protocol header.
* param - pointer to NAT proxy parameters.
* Returns: The number of bytes parsed or -1 if failed.
*/
IP_STATIC Ip_s32
ipnet_nat_proxy_dns_parse_answers(Ip_u8 *buf,
int buflen,
int offset,
int *newlen,
Ipnet_nat_dns_hdr *dns_hdr,
Ipnet_nat_proxy_param *param)
{
int i, count, origoffset, numa;
Ip_u16 type, cla, rlen;
int newbuflen = sizeof(dnsbuf);
Ipnet_nat_dns_transaction *trans;
numa = IP_GET_NTOHS(&dns_hdr->no_answ);
origoffset = offset;
for (i=0; i<numa; i++)
{
/* Get the name */
count = ipnet_nat_proxy_dns_decode_name(buf, buflen, offset, dnsname, sizeof(dnsname));
if (count < 0)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: could not decode dns name");
return -1;
}
/* Copy the name */
if (newbuflen - *newlen < count)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
ipcom_memcpy(&dnsbuf[*newlen], buf+offset, count);
*newlen += count;
offset += count;
/* Check space for type, class, ttl and record length */
if (buflen - offset < 10)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: message too short to parse answer");
return -1;
}
/* Get the type */
type = (Ip_u16)(IP_GET_NTOHS(buf+offset));
switch(type)
{
case IPNET_NAT_DNS_QTYPE_A:
type = IPNET_NAT_DNS_QTYPE_AAAA;
break;
case IPNET_NAT_DNS_QTYPE_PTR:
trans = ipnet_nat_proxy_dns_find_transaction(IPNET_NAT_DNS_QTYPE_PTR, dns_hdr, param);
if (trans != IP_NULL)
{
IPCOM_LOG4(DEBUG, "ipnet_nat_proxy_dns_parse_answers() :: found transaction:"
"id=%d port=%d addr=0x%08x type=%d",
trans->id, trans->srcport, trans->dstaddr, trans->type);
*newlen -= count; /* Move index back to before the name */
count = ipnet_nat_proxy_dns_encode_name(dnsbuf, newbuflen, *newlen, trans->ptrname);
if (count < 0)
{
ipnet_nat_proxy_dns_remove_transaction(trans);
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: could not encode dns name");
return -1;
}
*newlen += count;
if (i+1 == numa)
{
/* Remove transaction for last answer */
ipnet_nat_proxy_dns_remove_transaction(trans);
}
}
break;
default:
break;
}
/* Copy the type */
if (newbuflen - *newlen < 2)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
IP_SET_HTONS(&dnsbuf[*newlen], type);
*newlen += 2;
offset += 2;
/* Get the class */
cla = (Ip_u16)(IP_GET_NTOHS(buf+offset));
if (cla != IPNET_NAT_DNS_QCLASS_INET)
{
IPCOM_LOG1(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: unhandled class: %d", cla);
return -1;
}
/* Copy the class */
if (newbuflen - *newlen < 2)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
IP_SET_HTONS(&dnsbuf[*newlen], cla);
*newlen += 2;
offset += 2;
/* Copy the ttl */
if (newbuflen - *newlen < 4)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
ipcom_memcpy(&dnsbuf[*newlen], buf+offset, 4);
*newlen += 4;
offset += 4;
/* Get the record length */
rlen = (Ip_u16)(IP_GET_NTOHS(buf+offset));
if (buflen - offset < rlen)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: message too short to parse answer");
return -1;
}
/* Copy the record length */
if (newbuflen - *newlen < 2)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
if (type == IPNET_NAT_DNS_QTYPE_AAAA && rlen == 4)
{
/* Modify record length and make space for the AAAA record */
IP_SET_HTONS(&dnsbuf[*newlen], 16);
*newlen += 2;
/* Insert AAAA record data */
if (newbuflen - *newlen < 12)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
ipcom_memcpy(&dnsbuf[*newlen], param->prefix, 12);
*newlen += 12;
}
else
{
IP_SET_HTONS(&dnsbuf[*newlen], rlen);
*newlen += 2;
}
offset += 2;
/* Copy the record */
if (newbuflen - *newlen < rlen)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_answers() :: no space left in modified buffer");
return -1;
}
ipcom_memcpy(&dnsbuf[*newlen], buf+offset, rlen);
*newlen += rlen;
offset += rlen;
}
return offset - origoffset;
}
/*
*===========================================================================
* ipnet_nat_proxy_dns_parse_questions
*===========================================================================
* Description: Parses and modifies DNS questions in a DNS packet.
* Parameters: buf - pointer to buffer with the DNS questions.
* buflen - length of buffer with DNS questions.
* offset - offset in the buffer where the DNS questions begin.
* newlen - pointer to the length of the message if modified.
* dns_hdr - pointer to the DNS protocol header.
* param - pointer to NAT proxy parameters.
* Returns: The number of bytes parsed or -1 if failed.
*/
IP_STATIC Ip_s32
ipnet_nat_proxy_dns_parse_questions(Ip_u8 *buf,
int buflen,
int offset,
int *newlen,
Ipnet_nat_dns_hdr *dns_hdr,
Ipnet_nat_proxy_param *param)
{
int i, j, k, count, origoffset, numq, numa, request;
Ip_u16 type, cla, flags;
Ip_u8 addr[4];
Ipnet_nat_dns_transaction *trans;
int newbuflen = sizeof(dnsbuf);
Ip_u8 c, *zone;
numq = IP_GET_NTOHS(&dns_hdr->no_ques);
if (numq != 1)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: supports only one question per message");
return -1;
}
numa = IP_GET_NTOHS(&dns_hdr->no_answ);
flags = IP_GET_NTOHS(&dns_hdr->flags);
request = (flags & IPNET_NAT_DNS_QR_FLAG) != 0 ? 0 : 1;
origoffset = offset;
for (i=0; i<numq; i++)
{
/* Get the name */
count = ipnet_nat_proxy_dns_decode_name(buf, buflen, offset, dnsname, sizeof(dnsname));
if (count < 0)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: could not decode dns name");
return -1;
}
/* Copy the name */
if (newbuflen - *newlen < count)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: no space left in modified buffer");
return -1;
}
ipcom_memcpy(&dnsbuf[*newlen], buf+offset, count);
*newlen += count;
offset += count;
/* Check space for type and class */
if (buflen - offset < 4)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: message too short to parse question");
return -1;
}
/* Get the type */
type = (Ip_u16)(IP_GET_NTOHS(buf+offset));
switch(type)
{
case IPNET_NAT_DNS_QTYPE_AAAA:
if (request)
{
trans = ipnet_nat_proxy_dns_add_transaction(IPNET_NAT_DNS_QTYPE_A, dns_hdr, param, IP_NULL);
if (trans == IP_NULL)
{
IPCOM_LOG0(ERR, "ipnet_nat_proxy_dns_parse_questions() :: could not add transaction to list");
return -1;
}
else
{
IPCOM_LOG4(DEBUG, "ipnet_nat_proxy_dns_parse_questions() :: added transaction:"
"id=%d port=%d addr=0x%08x type=%d",
trans->id, trans->srcport, trans->dstaddr, trans->type);
}
type = IPNET_NAT_DNS_QTYPE_A; /* Change type to A */
}
break;
case IPNET_NAT_DNS_QTYPE_A:
if (!request)
{
trans = ipnet_nat_proxy_dns_find_transaction(IPNET_NAT_DNS_QTYPE_A, dns_hdr, param);
if (trans != IP_NULL)
{
IPCOM_LOG4(DEBUG, "ipnet_nat_proxy_dns_parse_questions() :: found transaction:"
"id=%d port=%d addr=0x%08x type=%d",
trans->id, trans->srcport, trans->dstaddr, trans->type);
ipnet_nat_proxy_dns_remove_transaction(trans);
}
else
{
return -1;
}
type = IPNET_NAT_DNS_QTYPE_AAAA; /* Change type back to AAAA */
}
break;
case IPNET_NAT_DNS_QTYPE_PTR:
if (request)
{
zone = (Ip_u8 *)ipcom_strstr((char *)dnsname, "ip6.int");
if (zone == IP_NULL)
zone = (Ip_u8 *)ipcom_strstr((char *)dnsname, "ip6.arpa");
if (zone == IP_NULL)
{
IPCOM_LOG0(DEBUG, "ipnet_nat_proxy_dns_parse_questions() :: unhandled zone in PTR request");
return -1;
}
/* Extract IPv4 part */
if (ipcom_strlen((char *)dnsname) != 64 + ipcom_strlen((char *)zone))
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: invalid name in PTR request");
return -1;
}
k=0;
for (j=3; j>=0; j--)
{
c = ipcom_tolower(dnsname[k]);
c = c > '9' ? c - 'a' + 10 : c - '0';
addr[j] = c;
k += 2;
c = ipcom_tolower(dnsname[k]);
c = c > '9' ? c - 'a' + 10 : c - '0';
c <<= 4;
addr[j] += c;
k += 2;
}
trans = ipnet_nat_proxy_dns_add_transaction(IPNET_NAT_DNS_QTYPE_PTR, dns_hdr, param, dnsname);
if (trans == IP_NULL)
{
IPCOM_LOG0(ERR, "ipnet_nat_proxy_dns_parse_questions() :: could not add transaction to list");
return -1;
}
else
{
IPCOM_LOG4(DEBUG, "ipnet_nat_proxy_dns_parse_questions() :: added transaction:"
"id=%d port=%d addr=0x%08x type=%d",
trans->id, trans->srcport, trans->dstaddr, trans->type);
}
/* Convert address to PTR name */
if (ipnet_nat_proxy_dns_ptr_name(dnsname, sizeof(dnsname), addr, IP_AF_INET, (Ip_u8 *)"in-addr.arpa") < 0)
{
ipnet_nat_proxy_dns_remove_transaction(trans);
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: could not encode PTR name");
return -1;
}
*newlen -= count; /* Move index back to before the name */
count = ipnet_nat_proxy_dns_encode_name(dnsbuf, newbuflen, *newlen, dnsname);
if (count < 0)
{
ipnet_nat_proxy_dns_remove_transaction(trans);
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: could not encode dns name");
return -1;
}
*newlen += count;
}
else
{
trans = ipnet_nat_proxy_dns_find_transaction(IPNET_NAT_DNS_QTYPE_PTR, dns_hdr, param);
if (trans != IP_NULL)
{
IPCOM_LOG4(DEBUG, "ipnet_nat_proxy_dns_parse_questions() :: found transaction:"
"id=%d port=%d addr=0x%08x type=%d",
trans->id, trans->srcport, trans->dstaddr, trans->type);
*newlen -= count; /* Move index back to before the name */
count = ipnet_nat_proxy_dns_encode_name(dnsbuf, newbuflen, *newlen, trans->ptrname);
if (count < 0)
{
ipnet_nat_proxy_dns_remove_transaction(trans);
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: could not encode dns name");
return -1;
}
*newlen += count;
if (numa == 0)
{
/* Remove the transaction if there are no answers */
ipnet_nat_proxy_dns_remove_transaction(trans);
}
}
else
{
return -1;
}
}
break;
default:
return -1;
}
/* Copy the type */
if (newbuflen - *newlen < 2)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: no space left in modified buffer");
return -1;
}
IP_SET_HTONS(&dnsbuf[*newlen], type);
*newlen += 2;
offset += 2;
/* Get the class */
cla = (Ip_u16)(IP_GET_NTOHS(buf+offset));
if (cla != IPNET_NAT_DNS_QCLASS_INET)
{
IPCOM_LOG1(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: unhandled class: %d", cla);
return -1;
}
/* Copy the class */
if (newbuflen - *newlen < 2)
{
IPCOM_LOG0(WARNING, "ipnet_nat_proxy_dns_parse_questions() :: no space left in modified buffer");
return -1;
}
IP_SET_HTONS(&dnsbuf[*newlen], cla);
*newlen += 2;
offset += 2;
}
return offset - origoffset;
}
/*
*===========================================================================
* ipnet_config_interface
*===========================================================================
* Description: Configures one interface if it exists and is UP.
* Parameters: fd - A socket descriptor
* ifname - The name of the interface to configure
* conf - The configuration to apply to the interface
* conf_len - Number of valid entries in the "conf" array
* pass - First pass (1) will add all addresses
* second pass (2) will add other things like gateways
* Returns: 0 = success
* <0 = error code
*
*/
IP_STATIC int
ipnet_config_interface(Ip_fd fd, char *ifname, char *conf[], int conf_len, int pass)
{
char *option;
char *option_org;
char *token;
int i;
int err;
ip_assert(pass == 1 || pass == 2);
if (ipcom_if_nametoindex(ifname) == 0)
{
/* Interface does not exist */
IPCOM_LOG1(INFO, "%s not attached - skipping", ifname);
return 0;
}
if (0 > (err = ipnet_config_bring_up_if(ifname)))
{
IPCOM_LOG1(INFO, "Failed to bring UP %s", ifname);
return 0;
}
for (i = 0; i < conf_len; i++)
{
option_org = option = ipcom_strdup(conf[i]);
if (option == IP_NULL)
return -IP_ERRNO_ENOMEM;
token = ipcom_strtok_r(option, " \t/", &option);
if (token == IP_NULL || ipcom_strcmp(token, "ifname") == 0)
{
/* Ignore */
err = 0;
}
#ifdef IPCOM_USE_INET
else if (ipcom_strcmp(token, "inet") == 0)
{
if (pass == 1)
err = ipnet_config_add_inet_addr(fd, ifname, option);
}
else if (ipcom_strcmp(token, "gateway") == 0)
{
if (pass == 2)
err = ipnet_config_add_gateway(fd, ifname, option);
}
#else
else if (ipcom_strcmp(token, "inet") == 0
|| ipcom_strcmp(token, "gateway") == 0)
IP_NOOP;
#endif /* IPCOM_USE_INET */
#ifdef IPCOM_USE_INET6
else if (ipcom_strcmp(token, "inet6") == 0)
{
if (pass == 1)
err = ipnet_config_add_inet6_addr(fd, ifname, option);
}
else if (ipcom_strcmp(token, "gateway6") == 0)
{
if (pass == 2)
err = ipnet_config_add_gateway6(ifname, option);
}
#else
else if (ipcom_strcmp(token, "inet6") == 0
|| ipcom_strcmp(token, "gateway6") == 0)
IP_NOOP;
#endif /* IPCOM_USE_INET6 */
else if (ipcom_strcmp(token, "devname") != 0)
/* Invalid configuration */
err = -IP_ERRNO_EINVAL;
ipcom_free(option_org);
if (err != 0)
{
if (err < 0)
err = -err;
IPCOM_LOG4(ERR, "failed on '%s' when configuring %s: %s (%d)",
conf[i], ifname, ipcom_strerror(err), err);
IP_PANIC();
break;
}
}
return err;
}
