static int protohandlerin(struct libalias *la, struct ip *pip, struct alias_data *ah) { AliasHandleCUSeeMeIn(la, pip, *ah->oaddr); return (0); }
static int UdpAliasIn(struct ip *pip) { struct udphdr *ud; struct alias_link *link; /* Return if proxy-only mode is enabled */ if (packetAliasMode & PKT_ALIAS_PROXY_ONLY) return PKT_ALIAS_OK; ud = (struct udphdr *) ((char *) pip + (pip->ip_hl << 2)); link = FindUdpTcpIn(pip->ip_src, pip->ip_dst, ud->uh_sport, ud->uh_dport, IPPROTO_UDP, 1); if (link != NULL) { struct in_addr alias_address; struct in_addr original_address; u_short alias_port; int accumulate; u_short *sptr; int r = 0; alias_address = GetAliasAddress(link); original_address = GetOriginalAddress(link); alias_port = ud->uh_dport; ud->uh_dport = GetOriginalPort(link); /* Special processing for IP encoding protocols */ if (ntohs(ud->uh_dport) == CUSEEME_PORT_NUMBER) AliasHandleCUSeeMeIn(pip, original_address); /* If NETBIOS Datagram, It should be alias address in UDP Data, too */ else if (ntohs(ud->uh_dport) == NETBIOS_DGM_PORT_NUMBER || ntohs(ud->uh_sport) == NETBIOS_DGM_PORT_NUMBER) r = AliasHandleUdpNbt(pip, link, &original_address, ud->uh_dport); else if (ntohs(ud->uh_dport) == NETBIOS_NS_PORT_NUMBER || ntohs(ud->uh_sport) == NETBIOS_NS_PORT_NUMBER) r = AliasHandleUdpNbtNS(pip, link, &alias_address, &alias_port, &original_address, &ud->uh_dport); /* If UDP checksum is not zero, then adjust since destination port */ /* is being unaliased and destination address is being altered. */ if (ud->uh_sum != 0) { accumulate = alias_port; accumulate -= ud->uh_dport; sptr = (u_short *) &alias_address; accumulate += *sptr++; accumulate += *sptr; sptr = (u_short *) &original_address; accumulate -= *sptr++; accumulate -= *sptr; ADJUST_CHECKSUM(accumulate, ud->uh_sum); } /* Restore original IP address */ DifferentialChecksum(&pip->ip_sum, (u_short *) &original_address, (u_short *) &pip->ip_dst, 2); pip->ip_dst = original_address; /* * If we cannot figure out the packet, ignore it. */ if (r < 0) return(PKT_ALIAS_IGNORED); else return(PKT_ALIAS_OK); } return(PKT_ALIAS_IGNORED); }