/* * Copyright (c) 1995 Danny Gasparovski. * * Please read the file COPYRIGHT for the * terms and conditions of the copyright. */ #include "qemu/osdep.h" #include "qemu-common.h" #include "slirp.h" #include "ip_icmp.h" #ifdef __sun__ #include <sys/filio.h> #endif static void sofcantrcvmore(struct socket *so); static void sofcantsendmore(struct socket *so); struct socket *solookup(struct socket **last, struct socket *head, struct sockaddr_storage *lhost, struct sockaddr_storage *fhost) { struct socket *so = *last; /* Optimisation */ if (so != head && sockaddr_equal(&(so->lhost.ss), lhost) && (!fhost || sockaddr_equal(&so->fhost.ss, fhost))) { return so; } for (so = head->so_next; so != head; so = so->so_next) { if (sockaddr_equal(&(so->lhost.ss), lhost) && (!fhost || sockaddr_equal(&so->fhost.ss, fhost))) { *last = so; return so; } } return (struct socket *)NULL; } /* * Create a new socket, initialise the fields * It is the responsibility of the caller to * insque() it into the correct linked-list */ struct socket * socreate(Slirp *slirp) { struct socket *so; so = (struct socket *)malloc(sizeof(struct socket)); if(so) { memset(so, 0, sizeof(struct socket)); so->so_state = SS_NOFDREF; so->s = -1; so->slirp = slirp; so->pollfds_idx = -1; } return(so); } /* * remque and free a socket, clobber cache */ void sofree(struct socket *so) { Slirp *slirp = so->slirp; struct mbuf *ifm; for (ifm = (struct mbuf *) slirp->if_fastq.qh_link; (struct quehead *) ifm != &slirp->if_fastq; ifm = ifm->ifq_next) { if (ifm->ifq_so == so) { ifm->ifq_so = NULL; } } for (ifm = (struct mbuf *) slirp->if_batchq.qh_link; (struct quehead *) ifm != &slirp->if_batchq; ifm = ifm->ifq_next) { if (ifm->ifq_so == so) { ifm->ifq_so = NULL; } } if (so->so_emu==EMU_RSH && so->extra) { sofree(so->extra); so->extra=NULL; } if (so == slirp->tcp_last_so) { slirp->tcp_last_so = &slirp->tcb; } else if (so == slirp->udp_last_so) { slirp->udp_last_so = &slirp->udb; } else if (so == slirp->icmp_last_so) { slirp->icmp_last_so = &slirp->icmp; } m_free(so->so_m); if(so->so_next && so->so_prev) remque(so); /* crashes if so is not in a queue */ free(so); } size_t sopreprbuf(struct socket *so, struct iovec *iov, int *np) { int n, lss, total; struct sbuf *sb = &so->so_snd; int len = sb->sb_datalen - sb->sb_cc; int mss = so->so_tcpcb->t_maxseg; DEBUG_CALL("sopreprbuf"); DEBUG_ARG("so = %p", so); if (len <= 0) return 0; iov[0].iov_base = sb->sb_wptr; iov[1].iov_base = NULL; iov[1].iov_len = 0; if (sb->sb_wptr < sb->sb_rptr) { iov[0].iov_len = sb->sb_rptr - sb->sb_wptr; /* Should never succeed, but... */ if (iov[0].iov_len > len) iov[0].iov_len = len; if (iov[0].iov_len > mss) iov[0].iov_len -= iov[0].iov_len%mss; n = 1; } else { iov[0].iov_len = (sb->sb_data + sb->sb_datalen) - sb->sb_wptr; /* Should never succeed, but... */ if (iov[0].iov_len > len) iov[0].iov_len = len; len -= iov[0].iov_len; if (len) { iov[1].iov_base = sb->sb_data; iov[1].iov_len = sb->sb_rptr - sb->sb_data; if(iov[1].iov_len > len) iov[1].iov_len = len; total = iov[0].iov_len + iov[1].iov_len; if (total > mss) { lss = total%mss; if (iov[1].iov_len > lss) { iov[1].iov_len -= lss; n = 2; } else { lss -= iov[1].iov_len; iov[0].iov_len -= lss; n = 1; } } else n = 2; } else { if (iov[0].iov_len > mss) iov[0].iov_len -= iov[0].iov_len%mss; n = 1; } } if (np) *np = n; return iov[0].iov_len + (n - 1) * iov[1].iov_len; } /* * Read from so's socket into sb_snd, updating all relevant sbuf fields * NOTE: This will only be called if it is select()ed for reading, so * a read() of 0 (or less) means it's disconnected */ int soread(struct socket *so) { int n, nn; struct sbuf *sb = &so->so_snd; struct iovec iov[2]; DEBUG_CALL("soread"); DEBUG_ARG("so = %p", so); /* * No need to check if there's enough room to read. * soread wouldn't have been called if there weren't */ sopreprbuf(so, iov, &n); #ifdef HAVE_READV nn = readv(so->s, (struct iovec *)iov, n); DEBUG_MISC((dfd, " ... read nn = %d bytes\n", nn)); #else nn = qemu_recv(so->s, iov[0].iov_base, iov[0].iov_len,0); #endif if (nn <= 0) { if (nn < 0 && (errno == EINTR || errno == EAGAIN)) return 0; else { int err; socklen_t slen = sizeof err; err = errno; if (nn == 0) { getsockopt(so->s, SOL_SOCKET, SO_ERROR, &err, &slen); } DEBUG_MISC((dfd, " --- soread() disconnected, nn = %d, errno = %d-%s\n", nn, errno,strerror(errno))); sofcantrcvmore(so); if (err == ECONNRESET || err == ECONNREFUSED || err == ENOTCONN || err == EPIPE) { tcp_drop(sototcpcb(so), err); } else { tcp_sockclosed(sototcpcb(so)); } return -1; } } #ifndef HAVE_READV /* * If there was no error, try and read the second time round * We read again if n = 2 (ie, there's another part of the buffer) * and we read as much as we could in the first read * We don't test for <= 0 this time, because there legitimately * might not be any more data (since the socket is non-blocking), * a close will be detected on next iteration. * A return of -1 won't (shouldn't) happen, since it didn't happen above */ if (n == 2 && nn == iov[0].iov_len) { int ret; ret = qemu_recv(so->s, iov[1].iov_base, iov[1].iov_len,0); if (ret > 0) nn += ret; } DEBUG_MISC((dfd, " ... read nn = %d bytes\n", nn)); #endif /* Update fields */ sb->sb_cc += nn; sb->sb_wptr += nn; if (sb->sb_wptr >= (sb->sb_data + sb->sb_datalen)) sb->sb_wptr -= sb->sb_datalen; return nn; } int soreadbuf(struct socket *so, const char *buf, int size) { int n, nn, copy = size; struct sbuf *sb = &so->so_snd; struct iovec iov[2]; DEBUG_CALL("soreadbuf"); DEBUG_ARG("so = %p", so); /* * No need to check if there's enough room to read. * soread wouldn't have been called if there weren't */ if (sopreprbuf(so, iov, &n) < size) goto err; nn = MIN(iov[0].iov_len, copy); memcpy(iov[0].iov_base, buf, nn); copy -= nn; buf += nn; if (copy == 0) goto done; memcpy(iov[1].iov_base, buf, copy); done: /* Update fields */ sb->sb_cc += size; sb->sb_wptr += size; if (sb->sb_wptr >= (sb->sb_data + sb->sb_datalen)) sb->sb_wptr -= sb->sb_datalen; return size; err: sofcantrcvmore(so); tcp_sockclosed(sototcpcb(so)); fprintf(stderr, "soreadbuf buffer to small"); return -1; } /* * Get urgent data * * When the socket is created, we set it SO_OOBINLINE, * so when OOB data arrives, we soread() it and everything * in the send buffer is sent as urgent data */ int sorecvoob(struct socket *so) { struct tcpcb *tp = sototcpcb(so); int ret; DEBUG_CALL("sorecvoob"); DEBUG_ARG("so = %p", so); /* * We take a guess at how much urgent data has arrived. * In most situations, when urgent data arrives, the next * read() should get all the urgent data. This guess will * be wrong however if more data arrives just after the * urgent data, or the read() doesn't return all the * urgent data. */ ret = soread(so); if (ret > 0) { tp->snd_up = tp->snd_una + so->so_snd.sb_cc; tp->t_force = 1; tcp_output(tp); tp->t_force = 0; } return ret; } /* * Send urgent data * There's a lot duplicated code here, but... */ int sosendoob(struct socket *so) { struct sbuf *sb = &so->so_rcv; char buff[2048]; /* XXX Shouldn't be sending more oob data than this */ int n, len; DEBUG_CALL("sosendoob"); DEBUG_ARG("so = %p", so); DEBUG_ARG("sb->sb_cc = %d", sb->sb_cc); if (so->so_urgc > 2048) so->so_urgc = 2048; /* XXXX */ if (sb->sb_rptr < sb->sb_wptr) { /* We can send it directly */ n = slirp_send(so, sb->sb_rptr, so->so_urgc, (MSG_OOB)); /* |MSG_DONTWAIT)); */ so->so_urgc -= n; DEBUG_MISC((dfd, " --- sent %d bytes urgent data, %d urgent bytes left\n", n, so->so_urgc)); } else { /* * Since there's no sendv or sendtov like writev, * we must copy all data to a linear buffer then * send it all */ len = (sb->sb_data + sb->sb_datalen) - sb->sb_rptr; if (len > so->so_urgc) len = so->so_urgc; memcpy(buff, sb->sb_rptr, len); so->so_urgc -= len; if (so->so_urgc) { n = sb->sb_wptr - sb->sb_data; if (n > so->so_urgc) n = so->so_urgc; memcpy((buff + len), sb->sb_data, n); so->so_urgc -= n; len += n; } n = slirp_send(so, buff, len, (MSG_OOB)); /* |MSG_DONTWAIT)); */ #ifdef DEBUG if (n != len) DEBUG_ERROR((dfd, "Didn't send all data urgently XXXXX\n")); #endif DEBUG_MISC((dfd, " ---2 sent %d bytes urgent data, %d urgent bytes left\n", n, so->so_urgc)); } sb->sb_cc -= n; sb->sb_rptr += n; if (sb->sb_rptr >= (sb->sb_data + sb->sb_datalen)) sb->sb_rptr -= sb->sb_datalen; return n; } /* * Write data from so_rcv to so's socket, * updating all sbuf field as necessary */ int sowrite(struct socket *so) { int n,nn; struct sbuf *sb = &so->so_rcv; int len = sb->sb_cc; struct iovec iov[2]; DEBUG_CALL("sowrite"); DEBUG_ARG("so = %p", so); if (so->so_urgc) { sosendoob(so); if (sb->sb_cc == 0) return 0; } /* * No need to check if there's something to write, * sowrite wouldn't have been called otherwise */ iov[0].iov_base = sb->sb_rptr; iov[1].iov_base = NULL; iov[1].iov_len = 0; if (sb->sb_rptr < sb->sb_wptr) { iov[0].iov_len = sb->sb_wptr - sb->sb_rptr; /* Should never succeed, but... */ if (iov[0].iov_len > len) iov[0].iov_len = len; n = 1; } else { iov[0].iov_len = (sb->sb_data + sb->sb_datalen) - sb->sb_rptr; if (iov[0].iov_len > len) iov[0].iov_len = len; len -= iov[0].iov_len; if (len) { iov[1].iov_base = sb->sb_data; iov[1].iov_len = sb->sb_wptr - sb->sb_data; if (iov[1].iov_len > len) iov[1].iov_len = len; n = 2; } else n = 1; } /* Check if there's urgent data to send, and if so, send it */ #ifdef HAVE_READV nn = writev(so->s, (const struct iovec *)iov, n); DEBUG_MISC((dfd, " ... wrote nn = %d bytes\n", nn)); #else nn = slirp_send(so, iov[0].iov_base, iov[0].iov_len,0); #endif /* This should never happen, but people tell me it does *shrug* */ if (nn < 0 && (errno == EAGAIN || errno == EINTR)) return 0; if (nn <= 0) { DEBUG_MISC((dfd, " --- sowrite disconnected, so->so_state = %x, errno = %d\n", so->so_state, errno)); sofcantsendmore(so); tcp_sockclosed(sototcpcb(so)); return -1; } #ifndef HAVE_READV if (n == 2 && nn == iov[0].iov_len) { int ret; ret = slirp_send(so, iov[1].iov_base, iov[1].iov_len,0); if (ret > 0) nn += ret; } DEBUG_MISC((dfd, " ... wrote nn = %d bytes\n", nn)); #endif /* Update sbuf */ sb->sb_cc -= nn; sb->sb_rptr += nn; if (sb->sb_rptr >= (sb->sb_data + sb->sb_datalen)) sb->sb_rptr -= sb->sb_datalen; /* * If in DRAIN mode, and there's no more data, set * it CANTSENDMORE */ if ((so->so_state & SS_FWDRAIN) && sb->sb_cc == 0) sofcantsendmore(so); return nn; } /* * recvfrom() a UDP socket */ void sorecvfrom(struct socket *so) { struct sockaddr_storage addr; struct sockaddr_storage saddr, daddr; socklen_t addrlen = sizeof(struct sockaddr_storage); DEBUG_CALL("sorecvfrom"); DEBUG_ARG("so = %p", so); if (so->so_type == IPPROTO_ICMP) { /* This is a "ping" reply */ char buff[256]; int len; len = recvfrom(so->s, buff, 256, 0, (struct sockaddr *)&addr, &addrlen); /* XXX Check if reply is "correct"? */ if(len == -1 || len == 0) { u_char code=ICMP_UNREACH_PORT; if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST; else if(errno == ENETUNREACH) code=ICMP_UNREACH_NET; DEBUG_MISC((dfd," udp icmp rx errno = %d-%s\n", errno,strerror(errno))); icmp_send_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno)); } else { icmp_reflect(so->so_m); so->so_m = NULL; /* Don't m_free() it again! */ } /* No need for this socket anymore, udp_detach it */ udp_detach(so); } else { /* A "normal" UDP packet */ struct mbuf *m; int len; #ifdef _WIN32 unsigned long n; #else int n; #endif m = m_get(so->slirp); if (!m) { return; } switch (so->so_ffamily) { case AF_INET: m->m_data += IF_MAXLINKHDR + sizeof(struct udpiphdr); break; case AF_INET6: m->m_data += IF_MAXLINKHDR + sizeof(struct ip6) + sizeof(struct udphdr); break; default: g_assert_not_reached(); break; } /* * XXX Shouldn't FIONREAD packets destined for port 53, * but I don't know the max packet size for DNS lookups */ len = M_FREEROOM(m); /* if (so->so_fport != htons(53)) { */ ioctlsocket(so->s, FIONREAD, &n); if (n > len) { n = (m->m_data - m->m_dat) + m->m_len + n + 1; m_inc(m, n); len = M_FREEROOM(m); } /* } */ m->m_len = recvfrom(so->s, m->m_data, len, 0, (struct sockaddr *)&addr, &addrlen); DEBUG_MISC((dfd, " did recvfrom %d, errno = %d-%s\n", m->m_len, errno,strerror(errno))); if(m->m_len<0) { /* Report error as ICMP */ switch (so->so_lfamily) { uint8_t code; case AF_INET: code = ICMP_UNREACH_PORT; if (errno == EHOSTUNREACH) { code = ICMP_UNREACH_HOST; } else if (errno == ENETUNREACH) { code = ICMP_UNREACH_NET; } DEBUG_MISC((dfd, " rx error, tx icmp ICMP_UNREACH:%i\n", code)); icmp_send_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno)); break; case AF_INET6: code = ICMP6_UNREACH_PORT; if (errno == EHOSTUNREACH) { code = ICMP6_UNREACH_ADDRESS; } else if (errno == ENETUNREACH) { code = ICMP6_UNREACH_NO_ROUTE; } DEBUG_MISC((dfd, " rx error, tx icmp6 ICMP_UNREACH:%i\n", code)); icmp6_send_error(so->so_m, ICMP6_UNREACH, code); break; default: g_assert_not_reached(); break; } m_free(m); } else { /* * Hack: domain name lookup will be used the most for UDP, * and since they'll only be used once there's no need * for the 4 minute (or whatever) timeout... So we time them * out much quicker (10 seconds for now...) */ if (so->so_expire) { if (so->so_fport == htons(53)) so->so_expire = curtime + SO_EXPIREFAST; else so->so_expire = curtime + SO_EXPIRE; } /* * If this packet was destined for CTL_ADDR, * make it look like that's where it came from */ saddr = addr; sotranslate_in(so, &saddr); daddr = so->lhost.ss; switch (so->so_ffamily) { case AF_INET: udp_output(so, m, (struct sockaddr_in *) &saddr, (struct sockaddr_in *) &daddr, so->so_iptos); break; case AF_INET6: udp6_output(so, m, (struct sockaddr_in6 *) &saddr, (struct sockaddr_in6 *) &daddr); break; default: g_assert_not_reached(); break; } } /* rx error */ } /* if ping packet */ } /* * sendto() a socket */ int sosendto(struct socket *so, struct mbuf *m) { int ret; struct sockaddr_storage addr; DEBUG_CALL("sosendto"); DEBUG_ARG("so = %p", so); DEBUG_ARG("m = %p", m); addr = so->fhost.ss; DEBUG_CALL(" sendto()ing)"); sotranslate_out(so, &addr); /* Don't care what port we get */ ret = sendto(so->s, m->m_data, m->m_len, 0, (struct sockaddr *)&addr, sockaddr_size(&addr)); if (ret < 0) return -1; /* * Kill the socket if there's no reply in 4 minutes, * but only if it's an expirable socket */ if (so->so_expire) so->so_expire = curtime + SO_EXPIRE; so->so_state &= SS_PERSISTENT_MASK; so->so_state |= SS_ISFCONNECTED; /* So that it gets select()ed */ return 0; } /* * Listen for incoming TCP connections */ struct socket * tcp_listen(Slirp *slirp, uint32_t haddr, u_int hport, uint32_t laddr, u_int lport, int flags) { struct sockaddr_in addr; struct socket *so; int s, opt = 1; socklen_t addrlen = sizeof(addr); memset(&addr, 0, addrlen); DEBUG_CALL("tcp_listen"); DEBUG_ARG("haddr = %x", haddr); DEBUG_ARG("hport = %d", hport); DEBUG_ARG("laddr = %x", laddr); DEBUG_ARG("lport = %d", lport); DEBUG_ARG("flags = %x", flags); so = socreate(slirp); if (!so) { return NULL; } /* Don't tcp_attach... we don't need so_snd nor so_rcv */ if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL) { free(so); return NULL; } insque(so, &slirp->tcb); /* * SS_FACCEPTONCE sockets must time out. */ if (flags & SS_FACCEPTONCE) so->so_tcpcb->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT*2; so->so_state &= SS_PERSISTENT_MASK; so->so_state |= (SS_FACCEPTCONN | flags); so->so_lfamily = AF_INET; so->so_lport = lport; /* Kept in network format */ so->so_laddr.s_addr = laddr; /* Ditto */ addr.sin_family = AF_INET; addr.sin_addr.s_addr = haddr; addr.sin_port = hport; if (((s = qemu_socket(AF_INET,SOCK_STREAM,0)) < 0) || (socket_set_fast_reuse(s) < 0) || (bind(s,(struct sockaddr *)&addr, sizeof(addr)) < 0) || (listen(s,1) < 0)) { int tmperrno = errno; /* Don't clobber the real reason we failed */ if (s >= 0) { closesocket(s); } sofree(so); /* Restore the real errno */ #ifdef _WIN32 WSASetLastError(tmperrno); #else errno = tmperrno; #endif return NULL; } qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int)); getsockname(s,(struct sockaddr *)&addr,&addrlen); so->so_ffamily = AF_INET; so->so_fport = addr.sin_port; if (addr.sin_addr.s_addr == 0 || addr.sin_addr.s_addr == loopback_addr.s_addr) so->so_faddr = slirp->vhost_addr; else so->so_faddr = addr.sin_addr; so->s = s; return so; } /* * Various session state calls * XXX Should be #define's * The socket state stuff needs work, these often get call 2 or 3 * times each when only 1 was needed */ void soisfconnecting(struct socket *so) { so->so_state &= ~(SS_NOFDREF|SS_ISFCONNECTED|SS_FCANTRCVMORE| SS_FCANTSENDMORE|SS_FWDRAIN); so->so_state |= SS_ISFCONNECTING; /* Clobber other states */ } void soisfconnected(struct socket *so) { so->so_state &= ~(SS_ISFCONNECTING|SS_FWDRAIN|SS_NOFDREF); so->so_state |= SS_ISFCONNECTED; /* Clobber other states */ } static void sofcantrcvmore(struct socket *so) { if ((so->so_state & SS_NOFDREF) == 0) { shutdown(so->s,0); } so->so_state &= ~(SS_ISFCONNECTING); if (so->so_state & SS_FCANTSENDMORE) { so->so_state &= SS_PERSISTENT_MASK; so->so_state |= SS_NOFDREF; /* Don't select it */ } else { so->so_state |= SS_FCANTRCVMORE; } } static void sofcantsendmore(struct socket *so) { if ((so->so_state & SS_NOFDREF) == 0) { shutdown(so->s,1); /* send FIN to fhost */ } so->so_state &= ~(SS_ISFCONNECTING); if (so->so_state & SS_FCANTRCVMORE) { so->so_state &= SS_PERSISTENT_MASK; so->so_state |= SS_NOFDREF; /* as above */ } else { so->so_state |= SS_FCANTSENDMORE; } } /* * Set write drain mode * Set CANTSENDMORE once all data has been write()n */ void sofwdrain(struct socket *so) { if (so->so_rcv.sb_cc) so->so_state |= SS_FWDRAIN; else sofcantsendmore(so); } /* * Translate addr in host addr when it is a virtual address */ void sotranslate_out(struct socket *so, struct sockaddr_storage *addr) { Slirp *slirp = so->slirp; struct sockaddr_in *sin = (struct sockaddr_in *)addr; struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr; switch (addr->ss_family) { case AF_INET: if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { /* It's an alias */ if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) { if (get_dns_addr(&sin->sin_addr) < 0) { sin->sin_addr = loopback_addr; } } else { sin->sin_addr = loopback_addr; } } DEBUG_MISC((dfd, " addr.sin_port=%d, " "addr.sin_addr.s_addr=%.16s\n", ntohs(sin->sin_port), inet_ntoa(sin->sin_addr))); break; case AF_INET6: if (in6_equal_net(&so->so_faddr6, &slirp->vprefix_addr6, slirp->vprefix_len)) { if (in6_equal(&so->so_faddr6, &slirp->vnameserver_addr6)) { uint32_t scope_id; if (get_dns6_addr(&sin6->sin6_addr, &scope_id) >= 0) { sin6->sin6_scope_id = scope_id; } else { sin6->sin6_addr = in6addr_loopback; } } else { sin6->sin6_addr = in6addr_loopback; } } break; default: break; } } void sotranslate_in(struct socket *so, struct sockaddr_storage *addr) { Slirp *slirp = so->slirp; struct sockaddr_in *sin = (struct sockaddr_in *)addr; struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr; switch (addr->ss_family) { case AF_INET: if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr; if ((so->so_faddr.s_addr & inv_mask) == inv_mask) { sin->sin_addr = slirp->vhost_addr; } else if (sin->sin_addr.s_addr == loopback_addr.s_addr || so->so_faddr.s_addr != slirp->vhost_addr.s_addr) { sin->sin_addr = so->so_faddr; } } break; case AF_INET6: if (in6_equal_net(&so->so_faddr6, &slirp->vprefix_addr6, slirp->vprefix_len)) { if (in6_equal(&sin6->sin6_addr, &in6addr_loopback) || !in6_equal(&so->so_faddr6, &slirp->vhost_addr6)) { sin6->sin6_addr = so->so_faddr6; } } break; default: break; } } /* * Translate connections from localhost to the real hostname */ void sotranslate_accept(struct socket *so) { Slirp *slirp = so->slirp; switch (so->so_ffamily) { case AF_INET: if (so->so_faddr.s_addr == INADDR_ANY || (so->so_faddr.s_addr & loopback_mask) == (loopback_addr.s_addr & loopback_mask)) { so->so_faddr = slirp->vhost_addr; } break; case AF_INET6: if (in6_equal(&so->so_faddr6, &in6addr_any) || in6_equal(&so->so_faddr6, &in6addr_loopback)) { so->so_faddr6 = slirp->vhost_addr6; } break; default: break; } }