| /* SPDX-License-Identifier: BSD-3-Clause */ |
| /* |
| * 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. 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" |
| |
| static uint8_t udp_tos(struct socket *so); |
| |
| void udp_init(Slirp *slirp) |
| { |
| slirp->udb.so_next = slirp->udb.so_prev = &slirp->udb; |
| slirp->udp_last_so = &slirp->udb; |
| } |
| |
| void udp_cleanup(Slirp *slirp) |
| { |
| struct socket *so, *so_next; |
| |
| for (so = slirp->udb.so_next; so != &slirp->udb; so = so_next) { |
| so_next = so->so_next; |
| udp_detach(so); |
| } |
| } |
| |
| /* m->m_data points at ip packet header |
| * m->m_len length ip packet |
| * ip->ip_len length data (IPDU) |
| */ |
| void udp_input(register struct mbuf *m, int iphlen) |
| { |
| Slirp *slirp = m->slirp; |
| M_DUP_DEBUG(slirp, m, 0, 0); |
| |
| register struct ip *ip; |
| register struct udphdr *uh; |
| int len; |
| struct ip save_ip; |
| struct socket *so; |
| struct sockaddr_storage lhost; |
| struct sockaddr_in *lhost4; |
| int ttl; |
| |
| DEBUG_CALL("udp_input"); |
| DEBUG_ARG("m = %p", m); |
| DEBUG_ARG("iphlen = %d", iphlen); |
| |
| /* |
| * 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); |
| iphlen = sizeof(struct ip); |
| } |
| |
| /* |
| * Get IP and UDP header together in first mbuf. |
| */ |
| ip = mtod_check(m, iphlen + sizeof(struct udphdr)); |
| if (ip == NULL) { |
| goto bad; |
| } |
| uh = (struct udphdr *)((char *)ip + iphlen); |
| |
| /* |
| * Make mbuf data length reflect UDP length. |
| * If not enough data to reflect UDP length, drop. |
| */ |
| len = ntohs((uint16_t)uh->uh_ulen); |
| |
| if (ip->ip_len != len) { |
| if (len > ip->ip_len) { |
| goto bad; |
| } |
| m_adj(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 (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; |
| if (cksum(m, len + sizeof(struct ip))) { |
| goto bad; |
| } |
| } |
| |
| lhost.ss_family = AF_INET; |
| lhost4 = (struct sockaddr_in *)&lhost; |
| lhost4->sin_addr = ip->ip_src; |
| lhost4->sin_port = uh->uh_sport; |
| |
| /* |
| * handle DHCP/BOOTP |
| */ |
| if (ntohs(uh->uh_dport) == BOOTP_SERVER && |
| (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr || |
| ip->ip_dst.s_addr == 0xffffffff)) { |
| bootp_input(m); |
| goto bad; |
| } |
| |
| /* |
| * handle TFTP |
| */ |
| if (ntohs(uh->uh_dport) == TFTP_SERVER && |
| ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) { |
| m->m_data += iphlen; |
| m->m_len -= iphlen; |
| tftp_input(&lhost, m); |
| m->m_data -= iphlen; |
| m->m_len += iphlen; |
| goto bad; |
| } |
| |
| if (slirp->restricted) { |
| goto bad; |
| } |
| |
| /* |
| * Locate pcb for datagram. |
| */ |
| so = solookup(&slirp->udp_last_so, &slirp->udb, &lhost, NULL); |
| |
| if (so == NULL) { |
| /* |
| * If there's no socket for this packet, |
| * create one |
| */ |
| so = socreate(slirp, IPPROTO_UDP); |
| if (udp_attach(so, AF_INET) == -1) { |
| DEBUG_MISC(" udp_attach errno = %d-%s", errno, strerror(errno)); |
| sofree(so); |
| goto bad; |
| } |
| |
| /* |
| * Setup fields |
| */ |
| so->so_lfamily = AF_INET; |
| so->so_laddr = ip->ip_src; |
| so->so_lport = 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_ffamily = AF_INET; |
| so->so_faddr = ip->ip_dst; /* XXX */ |
| so->so_fport = uh->uh_dport; /* XXX */ |
| |
| iphlen += sizeof(struct udphdr); |
| m->m_len -= iphlen; |
| m->m_data += iphlen; |
| |
| /* |
| * Check for TTL |
| */ |
| ttl = save_ip.ip_ttl-1; |
| if (ttl <= 0) { |
| m->m_len += iphlen; |
| m->m_data -= iphlen; |
| *ip = save_ip; |
| DEBUG_MISC("udp ttl exceeded"); |
| icmp_send_error(m, ICMP_TIMXCEED, ICMP_TIMXCEED_INTRANS, 0, NULL); |
| goto bad; |
| } |
| setsockopt(so->s, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)); |
| |
| /* |
| * Now we sendto() the packet. |
| */ |
| if (sosendto(so, m) == -1) { |
| m->m_len += iphlen; |
| m->m_data -= iphlen; |
| *ip = save_ip; |
| DEBUG_MISC("udp tx errno = %d-%s", errno, strerror(errno)); |
| icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno)); |
| goto bad; |
| } |
| |
| m_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: |
| m_free(m); |
| } |
| |
| int udp_output(struct socket *so, struct mbuf *m, struct sockaddr_in *saddr, |
| struct sockaddr_in *daddr, int iptos) |
| { |
| Slirp *slirp = m->slirp; |
| char addr[INET_ADDRSTRLEN]; |
| |
| M_DUP_DEBUG(slirp, m, 0, sizeof(struct udpiphdr)); |
| |
| register struct udpiphdr *ui; |
| int error = 0; |
| |
| DEBUG_CALL("udp_output"); |
| DEBUG_ARG("so = %p", so); |
| DEBUG_ARG("m = %p", m); |
| DEBUG_ARG("saddr = %s", inet_ntop(AF_INET, &saddr->sin_addr, addr, sizeof(addr))); |
| DEBUG_ARG("daddr = %s", inet_ntop(AF_INET, &daddr->sin_addr, addr, sizeof(addr))); |
| |
| /* |
| * 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 = mtod(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)); |
| /* XXXXX Check for from-one-location sockets, or from-any-location sockets |
| */ |
| ui->ui_src = saddr->sin_addr; |
| ui->ui_dst = daddr->sin_addr; |
| ui->ui_sport = saddr->sin_port; |
| ui->ui_dport = daddr->sin_port; |
| ui->ui_ulen = ui->ui_len; |
| |
| /* |
| * Stuff checksum and output datagram. |
| */ |
| ui->ui_sum = 0; |
| if ((ui->ui_sum = cksum(m, m->m_len)) == 0) |
| ui->ui_sum = 0xffff; |
| ((struct ip *)ui)->ip_len = m->m_len; |
| |
| ((struct ip *)ui)->ip_ttl = IPDEFTTL; |
| ((struct ip *)ui)->ip_tos = iptos; |
| |
| error = ip_output(so, m); |
| |
| return (error); |
| } |
| |
| int udp_attach(struct socket *so, unsigned short af) |
| { |
| so->s = slirp_socket(af, SOCK_DGRAM, 0); |
| if (so->s != -1) { |
| if (slirp_bind_outbound(so, af) != 0) { |
| // bind failed - close socket |
| closesocket(so->s); |
| so->s = -1; |
| return -1; |
| } |
| |
| #ifdef __linux__ |
| { |
| int opt = 1; |
| switch (af) { |
| case AF_INET: |
| setsockopt(so->s, IPPROTO_IP, IP_RECVERR, &opt, sizeof(opt)); |
| break; |
| case AF_INET6: |
| setsockopt(so->s, IPPROTO_IPV6, IPV6_RECVERR, &opt, sizeof(opt)); |
| break; |
| default: |
| g_assert_not_reached(); |
| } |
| } |
| #endif |
| |
| so->so_expire = curtime + SO_EXPIRE; |
| slirp_insque(so, &so->slirp->udb); |
| } |
| so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque); |
| return (so->s); |
| } |
| |
| void udp_detach(struct socket *so) |
| { |
| so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque); |
| closesocket(so->s); |
| sofree(so); |
| } |
| |
| static const struct tos_t udptos[] = { { 0, 53, IPTOS_LOWDELAY, 0 }, /* DNS */ |
| { 0, 0, 0, 0 } }; |
| |
| static uint8_t udp_tos(struct socket *so) |
| { |
| int i = 0; |
| |
| while (udptos[i].tos) { |
| if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) || |
| (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) { |
| if (so->slirp->enable_emu) |
| so->so_emu = udptos[i].emu; |
| return udptos[i].tos; |
| } |
| i++; |
| } |
| |
| return 0; |
| } |
| |
| struct socket *udpx_listen(Slirp *slirp, |
| const struct sockaddr *haddr, socklen_t haddrlen, |
| const struct sockaddr *laddr, socklen_t laddrlen, |
| int flags) |
| { |
| struct socket *so; |
| socklen_t addrlen; |
| int save_errno; |
| |
| so = socreate(slirp, IPPROTO_UDP); |
| so->s = slirp_socket(haddr->sa_family, SOCK_DGRAM, 0); |
| if (so->s < 0) { |
| save_errno = errno; |
| sofree(so); |
| errno = save_errno; |
| return NULL; |
| } |
| if (haddr->sa_family == AF_INET6) |
| slirp_socket_set_v6only(so->s, (flags & SS_HOSTFWD_V6ONLY) != 0); |
| so->so_expire = curtime + SO_EXPIRE; |
| slirp_insque(so, &slirp->udb); |
| |
| if (bind(so->s, haddr, haddrlen) < 0) { |
| save_errno = errno; |
| udp_detach(so); |
| errno = save_errno; |
| return NULL; |
| } |
| slirp_socket_set_fast_reuse(so->s); |
| |
| addrlen = sizeof(so->fhost); |
| getsockname(so->s, &so->fhost.sa, &addrlen); |
| sotranslate_accept(so); |
| |
| sockaddr_copy(&so->lhost.sa, sizeof(so->lhost), laddr, laddrlen); |
| |
| if (flags != SS_FACCEPTONCE) |
| so->so_expire = 0; |
| so->so_state &= SS_PERSISTENT_MASK; |
| so->so_state |= SS_ISFCONNECTED | flags; |
| so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque); |
| |
| return so; |
| } |
| |
| struct socket *udp_listen(Slirp *slirp, uint32_t haddr, unsigned hport, |
| uint32_t laddr, unsigned lport, int flags) |
| { |
| struct sockaddr_in hsa, lsa; |
| |
| memset(&hsa, 0, sizeof(hsa)); |
| hsa.sin_family = AF_INET; |
| hsa.sin_addr.s_addr = haddr; |
| hsa.sin_port = hport; |
| |
| memset(&lsa, 0, sizeof(lsa)); |
| lsa.sin_family = AF_INET; |
| lsa.sin_addr.s_addr = laddr; |
| lsa.sin_port = lport; |
| |
| return udpx_listen(slirp, (const struct sockaddr *) &hsa, sizeof(hsa), (struct sockaddr *) &lsa, sizeof(lsa), flags); |
| } |
