diff options
Diffstat (limited to 'slirp2/udp.c')
-rw-r--r-- | slirp2/udp.c | 495 |
1 files changed, 495 insertions, 0 deletions
diff --git a/slirp2/udp.c b/slirp2/udp.c new file mode 100644 index 0000000..9305cfd --- /dev/null +++ b/slirp2/udp.c @@ -0,0 +1,495 @@ +/* + * Copyright (c) 1982, 1986, 1988, 1990, 1993 + * The Regents of the University of California. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)udp_usrreq.c 8.4 (Berkeley) 1/21/94 + * udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp + */ + +/* + * Changes and additions relating to SLiRP + * Copyright (c) 1995 Danny Gasparovski. + * + * Please read the file COPYRIGHT for the + * terms and conditions of the copyright. + */ + +#include <slirp.h> +#include "ip_icmp.h" +#define SLIRP_COMPILATION 1 +#include "sockets.h" + +struct udpstat udpstat; + +struct socket udb; + +/* + * UDP protocol implementation. + * Per RFC 768, August, 1980. + */ +#ifndef COMPAT_42 +int udpcksum = 1; +#else +int udpcksum = 0; /* XXX */ +#endif + +struct socket *udp_last_so = &udb; + +void +udp_init() +{ + udb.so_next = udb.so_prev = &udb; +} +/* m->m_data points at ip packet header + * m->m_len length ip packet + * ip->ip_len length data (IPDU) + */ +void +udp_input(m, iphlen) + register MBuf m; + int iphlen; +{ + register struct ip *ip; + register struct udphdr *uh; +/* MBuf opts = 0;*/ + int len; + struct ip save_ip; + struct socket *so; + + DEBUG_CALL("udp_input"); + DEBUG_ARG("m = %lx", (long)m); + DEBUG_ARG("iphlen = %d", iphlen); + + udpstat.udps_ipackets++; + + /* + * Strip IP options, if any; should skip this, + * make available to user, and use on returned packets, + * but we don't yet have a way to check the checksum + * with options still present. + */ + if(iphlen > sizeof(struct ip)) { + ip_stripoptions(m, (MBuf )0); + iphlen = sizeof(struct ip); + } + + /* + * Get IP and UDP header together in first mbuf. + */ + ip = MBUF_TO(m, struct ip *); + uh = (struct udphdr *)((caddr_t)ip + iphlen); + + /* + * Make mbuf data length reflect UDP length. + * If not enough data to reflect UDP length, drop. + */ + len = ntohs((u_int16_t)uh->uh_ulen); + + if (ip->ip_len != len) { + if (len > ip->ip_len) { + udpstat.udps_badlen++; + goto bad; + } + mbuf_trim(m, len - ip->ip_len); + ip->ip_len = len; + } + + /* + * Save a copy of the IP header in case we want restore it + * for sending an ICMP error message in response. + */ + save_ip = *ip; + save_ip.ip_len+= iphlen; /* tcp_input subtracts this */ + + /* + * Checksum extended UDP header and data. + */ + if (udpcksum && uh->uh_sum) { + memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr)); + ((struct ipovly *)ip)->ih_x1 = 0; + ((struct ipovly *)ip)->ih_len = uh->uh_ulen; + /* keep uh_sum for ICMP reply + * uh->uh_sum = cksum(m, len + sizeof (struct ip)); + * if (uh->uh_sum) { + */ + if(cksum(m, len + sizeof(struct ip))) { + udpstat.udps_badsum++; + goto bad; + } + } + + /* + * handle DHCP/BOOTP + */ + if (port_geth(uh->uh_dport) == BOOTP_SERVER) { + bootp_input(m); + goto bad; + } + + /* + * handle TFTP + */ + if (port_geth(uh->uh_dport) == TFTP_SERVER) { + tftp_input(m); + goto bad; + } + + /* + * Locate pcb for datagram. + */ + so = udp_last_so; + if (so->so_laddr_port != port_geth(uh->uh_sport) || + so->so_laddr_ip != ip_geth(ip->ip_src)) { + struct socket *tmp; + + for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next) { + if (tmp->so_laddr_port == port_geth(uh->uh_sport) && + tmp->so_laddr_ip == ip_geth(ip->ip_src)) { + tmp->so_faddr_ip = ip_geth(ip->ip_dst); + tmp->so_faddr_port = port_geth(uh->uh_dport); + so = tmp; + break; + } + } + if (tmp == &udb) { + so = NULL; + } else { + udpstat.udpps_pcbcachemiss++; + udp_last_so = so; + } + } + + if (so == NULL) { + /* + * If there's no socket for this packet, + * create one + */ + if ((so = socreate()) == NULL) goto bad; + if(udp_attach(so) == -1) { + DEBUG_MISC((dfd," udp_attach errno = %d-%s\n", + errno,errno_str)); + sofree(so); + goto bad; + } + + /* + * Setup fields + */ + /* udp_last_so = so; */ + so->so_laddr_ip = ip_geth(ip->ip_src); + so->so_laddr_port = port_geth(uh->uh_sport); + + if ((so->so_iptos = udp_tos(so)) == 0) + so->so_iptos = ip->ip_tos; + + /* + * XXXXX Here, check if it's in udpexec_list, + * and if it is, do the fork_exec() etc. + */ + } + + so->so_faddr_ip = ip_geth(ip->ip_dst); /* XXX */ + so->so_faddr_port = port_geth(uh->uh_dport); /* XXX */ + + iphlen += sizeof(struct udphdr); + m->m_len -= iphlen; + m->m_data += iphlen; + + /* + * Now we sendto() the packet. + */ + if (so->so_emu) + udp_emu(so, m); + + if(sosendto(so,m) == -1) { + m->m_len += iphlen; + m->m_data -= iphlen; + *ip=save_ip; + DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno, errno_str)); + icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,errno_str); + } + + mbuf_free(so->so_m); /* used for ICMP if error on sorecvfrom */ + + /* restore the orig mbuf packet */ + m->m_len += iphlen; + m->m_data -= iphlen; + *ip=save_ip; + so->so_m=m; /* ICMP backup */ + + return; +bad: + mbuf_free(m); + /* if (opts) mbuf_free(opts); */ + return; +} + +int udp_output2_(struct socket* so, MBuf m, + const SockAddress* saddr, + const SockAddress* daddr, + int iptos) +{ + register struct udpiphdr *ui; + uint32_t saddr_ip = sock_address_get_ip(saddr); + uint32_t daddr_ip = sock_address_get_ip(daddr); + int saddr_port = sock_address_get_port(saddr); + int daddr_port = sock_address_get_port(daddr); + int error = 0; + + DEBUG_CALL("udp_output"); + DEBUG_ARG("so = %lx", (long)so); + DEBUG_ARG("m = %lx", (long)m); + DEBUG_ARG("saddr = %lx", (long) saddr_ip); + DEBUG_ARG("daddr = %lx", (long) daddr_ip); + + /* + * Adjust for header + */ + m->m_data -= sizeof(struct udpiphdr); + m->m_len += sizeof(struct udpiphdr); + + /* + * Fill in mbuf with extended UDP header + * and addresses and length put into network format. + */ + ui = MBUF_TO(m, struct udpiphdr *); + memset(&ui->ui_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr)); + ui->ui_x1 = 0; + ui->ui_pr = IPPROTO_UDP; + ui->ui_len = htons(m->m_len - sizeof(struct ip)); /* + sizeof (struct udphdr)); */ + /* XXXXX Check for from-one-location sockets, or from-any-location sockets */ + ui->ui_src = ip_seth(saddr_ip); + ui->ui_dst = ip_seth(daddr_ip); + ui->ui_sport = port_seth(saddr_port); + ui->ui_dport = port_seth(daddr_port); + ui->ui_ulen = ui->ui_len; + + /* + * Stuff checksum and output datagram. + */ + ui->ui_sum = 0; + if (udpcksum) { + if ((ui->ui_sum = cksum(m, /* sizeof (struct udpiphdr) + */ m->m_len)) == 0) + ui->ui_sum = 0xffff; + } + ((struct ip *)ui)->ip_len = m->m_len; + + ((struct ip *)ui)->ip_ttl = ip_defttl; + ((struct ip *)ui)->ip_tos = iptos; + + udpstat.udps_opackets++; + + error = ip_output(so, m); + + return (error); +} + +int udp_output_(struct socket *so, MBuf m, SockAddress* from) +{ + SockAddress saddr, daddr; + uint32_t saddr_ip; + uint16_t saddr_port; + + saddr_ip = sock_address_get_ip(from); + saddr_port = sock_address_get_port(from); + + if ((so->so_faddr_ip & 0xffffff00) == special_addr_ip) { + saddr_ip = so->so_faddr_ip; + if ((so->so_faddr_ip & 0x000000ff) == 0xff) + saddr_ip = alias_addr_ip; + } + + sock_address_init_inet( &saddr, saddr_ip, saddr_port ); + sock_address_init_inet( &daddr, so->so_laddr_ip, so->so_laddr_port ); + + return udp_output2_(so, m, &saddr, &daddr, so->so_iptos); +} + +int +udp_attach(so) + struct socket *so; +{ + so->s = socket_anyaddr_server( 0, SOCKET_DGRAM ); + if (so->s != -1) { + /* success, insert in queue */ + so->so_expire = curtime + SO_EXPIRE; + insque(so,&udb); + } + return(so->s); +} + +void +udp_detach(so) + struct socket *so; +{ + socket_close(so->s); + /* if (so->so_m) mbuf_free(so->so_m); done by sofree */ + + sofree(so); +} + +struct tos_t udptos[] = { + {0, 53, IPTOS_LOWDELAY, 0}, /* DNS */ + {517, 517, IPTOS_LOWDELAY, EMU_TALK}, /* talk */ + {518, 518, IPTOS_LOWDELAY, EMU_NTALK}, /* ntalk */ + {0, 7648, IPTOS_LOWDELAY, EMU_CUSEEME}, /* Cu-Seeme */ + {0, 0, 0, 0} +}; + +u_int8_t +udp_tos(so) + struct socket *so; +{ + int i = 0; + + while(udptos[i].tos) { + if ((udptos[i].fport && so->so_faddr_port == udptos[i].fport) || + (udptos[i].lport && so->so_laddr_port == udptos[i].lport)) { + so->so_emu = udptos[i].emu; + return udptos[i].tos; + } + i++; + } + + return 0; +} + +/* + * Here, talk/ytalk/ntalk requests must be emulated + */ +void +udp_emu(so, m) + struct socket *so; + MBuf m; +{ + SockAddress sockaddr; + +struct cu_header { + uint16_t d_family; // destination family + uint16_t d_port; // destination port + uint32_t d_addr; // destination address + uint16_t s_family; // source family + uint16_t s_port; // source port + uint32_t so_addr; // source address + uint32_t seqn; // sequence number + uint16_t message; // message + uint16_t data_type; // data type + uint16_t pkt_len; // packet length +} *cu_head; + + switch(so->so_emu) { + + case EMU_CUSEEME: + + /* + * Cu-SeeMe emulation. + * Hopefully the packet is more that 16 bytes long. We don't + * do any other tests, just replace the address and port + * fields. + */ + if (m->m_len >= sizeof (*cu_head)) { + if (socket_get_address(so->s, &sockaddr) < 0) + return; + + cu_head = MBUF_TO(m, struct cu_header *); + cu_head->s_port = htons( sock_address_get_port(&sockaddr)); + cu_head->so_addr = htonl( sock_address_get_ip(&sockaddr)); + } + + return; + } +} + +struct socket * +udp_listen(port, laddr, lport, flags) + u_int port; + u_int32_t laddr; + u_int lport; + int flags; +{ + struct socket *so; + SockAddress addr; + uint32_t addr_ip; + + if ((so = socreate()) == NULL) { + free(so); + return NULL; + } + so->s = socket_anyaddr_server( port, SOCKET_DGRAM ); + so->so_expire = curtime + SO_EXPIRE; + so->so_haddr_port = port; + insque(so,&udb); + + if (so->s < 0) { + udp_detach(so); + return NULL; + } + + socket_get_address(so->s, &addr); + + so->so_faddr_port = sock_address_get_port(&addr); + addr_ip = sock_address_get_ip(&addr); + + if (addr_ip == 0 || addr_ip == loopback_addr_ip) + so->so_faddr_ip = alias_addr_ip; + else + so->so_faddr_ip = addr_ip; + + so->so_laddr_port = lport; + so->so_laddr_ip = laddr; + if (flags != SS_FACCEPTONCE) + so->so_expire = 0; + + so->so_state = SS_ISFCONNECTED; + + return so; +} + +int udp_unlisten (u_int port) +{ + struct socket *so; + + for (so = udb.so_next; so != &udb; so = so->so_next) { + if (so->so_haddr_port == port) { + break; + } + } + + if (so == &udb) + return -1; + + sofcantrcvmore( so ); + sofcantsendmore( so ); + socket_close( so->s ); + so->s = -1; + sofree( so ); + return 0; +} |