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srsLTE
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Removing broadcats hack. Returning to a simple TUN insterface on the MBMS-GW.

This commit is contained in:
Pedro Alvarez 2018-06-29 11:27:12 +01:00
parent badbb1de77
commit e2e82cc464
1 changed files with 1 additions and 60 deletions
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61
srsepc/src/mbms-gw/mbms-gw.cc
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@ -285,8 +285,6 @@ mbms_gw::handle_sgi_md_pdu(srslte::byte_buffer_t *msg)
{
uint8_t version;
srslte::gtpu_header_t header;
in_addr_t baddr = inet_addr("172.16.0.255");
in_addr_t saddr = inet_addr("172.16.0.254");
//Setup GTP-U header
header.flags = 0x30;
@ -301,44 +299,14 @@ mbms_gw::handle_sgi_md_pdu(srslte::byte_buffer_t *msg)
return;
}
//IP+UDP Headers
//IP Headers
struct iphdr *iph = (struct iphdr *) msg->msg;
struct udphdr *udph = (struct udphdr *) (msg->msg + iph->ihl*4);
if(iph->version != 4)
{
m_mbms_gw_log->warning("IPv6 not supported yet.\n");
return;
}
//Replace Destination IP with broadcast address
iph->daddr = baddr;
//Replace Source IP with address in same subnet
iph->saddr = saddr;
//Replace IP cheksum
iph->check = 0;
iph->check = in_cksum((uint16_t*)msg->msg,4*(msg->msg[0] & 0x0F));
//Set Pseudo Header
struct pseudo_hdr phdr;
phdr.src_addr = iph->saddr;
phdr.dst_addr = iph->daddr;
phdr.protocol = IPPROTO_UDP;
phdr.placeholder = 0;
phdr.udp_len = udph->len;
//Set Pseudo Datagram
udph->check = 0;
int psize = sizeof(struct pseudo_hdr) + ntohs(udph->len);
uint8_t * pseudo_dgram = (uint8_t*) malloc(psize);
memcpy(pseudo_dgram, &phdr,sizeof(struct pseudo_hdr));
memcpy(pseudo_dgram+sizeof(pseudo_hdr),udph,ntohs(udph->len));
//Recompute UDP checksum
udph->check = in_cksum((uint16_t*) pseudo_dgram, psize);
free(pseudo_dgram);
//Write GTP-U header into packet
if(!srslte::gtpu_write_header(&header, msg))
{
@ -355,31 +323,4 @@ mbms_gw::handle_sgi_md_pdu(srslte::byte_buffer_t *msg)
}
}
uint16_t
mbms_gw::in_cksum(uint16_t *iphdr, int count)
{
//RFC 1071
uint32_t sum = 0;
uint16_t padd = 0;
uint16_t result;
while(count > 1)
{
sum+= *iphdr++;
count -= 2;
}
if( count > 0 )
{
padd = * (uint8_t *) iphdr;
sum += padd;
}
/*Fold 32-bit sum to 16-bit*/
// while(sum>>16)
// sum = (sum & 0xffff) + (sum >> 16);
sum = (sum>>16)+(sum & 0xFFFF);
sum = sum + (sum >> 16);
result = (uint16_t) ~sum;
return result;
}
} //namespace srsepc