/* * 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 = %lx", (long )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 { DEBUG_MISC((dfd, " --- soread() disconnected, nn = %d, errno = %d-%s\n", nn, errno,strerror(errno))); sofcantrcvmore(so); 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 wont (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; }
/** * Analyze the info request message sent by the client to see what data it * provided and what it wants to have. The information is gathered in the * "requested_infos" struct. Note that client_id (if provided) points into * the odata region, thus the caller must keep odata valid as long as it * needs to access the requested_infos struct. */ static int dhcpv6_parse_info_request(uint8_t *odata, int olen, struct requested_infos *ri) { int i, req_opt; while (olen > 4) { /* Parse one option */ int option = odata[0] << 8 | odata[1]; int len = odata[2] << 8 | odata[3]; if (len + 4 > olen) { qemu_log_mask(LOG_GUEST_ERROR, "Guest sent bad DHCPv6 packet!\n"); return -E2BIG; } switch (option) { case OPTION_IAADDR: /* According to RFC3315, we must discard requests with IA option */ return -EINVAL; case OPTION_CLIENTID: if (len > 256) { /* Avoid very long IDs which could cause problems later */ return -E2BIG; } ri->client_id = odata + 4; ri->client_id_len = len; break; case OPTION_ORO: /* Option request option */ if (len & 1) { return -EINVAL; } /* Check which options the client wants to have */ for (i = 0; i < len; i += 2) { req_opt = odata[4 + i] << 8 | odata[4 + i + 1]; switch (req_opt) { case OPTION_DNS_SERVERS: ri->want_dns = true; break; case OPTION_BOOTFILE_URL: ri->want_boot_url = true; break; default: DEBUG_MISC((dfd, "dhcpv6: Unsupported option request %d\n", req_opt)); } } break; default: DEBUG_MISC((dfd, "dhcpv6 info req: Unsupported option %d, len=%d\n", option, len)); } odata += len + 4; olen -= len + 4; } return 0; }
/* * 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 = %lx", (long)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; }
int slirp_log_dns(struct mbuf* m, int dropped) { char dns_query[256]; int c = 0; int i= 0; int index = 0; int offset = 40 + 1; int trim_bytes = 4; if (!dns_log_fd) return -1; if (m->m_len < offset || m->m_len > 300) { DEBUG_MISC((dfd,"Malformed DNS qeury, length %d \n", (int)m->m_len)); return -1; } for (i = offset; i < m->m_len - trim_bytes && index < sizeof(dns_query); i++, index++) { c = m->m_data[i]; if (c < ' ' || c > '~') c = '.'; dns_query[index] = (char)c; } dns_query[index] = '\0'; if (!dropped) { fprintf(dns_log_fd, "Sent DNS query for, %s\n" , dns_query); } else { fprintf(dns_log_fd, "Dropped DNS query for, %s\n" , dns_query); } fflush(dns_log_fd); return 1; }
void slirp_add_allow(unsigned long dst_addr, int dst_lport, int dst_hport, u_int8_t proto) { struct fw_allow_entry** ate; switch (proto) { case IPPROTO_TCP: ate = &allow_tcp_entries; break; case IPPROTO_UDP: ate = &allow_udp_entries; break; default: return; } while(*ate != NULL) ate = &(*ate)->next; *ate = malloc(sizeof(**ate)); if (*ate == NULL) { DEBUG_MISC((dfd, "Unable to create new firewall record, malloc failed\n")); exit(-1); } (*ate)->next = NULL; (*ate)->dst_addr = dst_addr; (*ate)->dst_lport = dst_lport; (*ate)->dst_hport = dst_hport; }
static int icmp_send(struct socket *so, struct mbuf *m, int hlen) { struct ip *ip = mtod(m, struct ip *); struct sockaddr_in addr; so->s = qemu_socket(AF_INET, SOCK_DGRAM, IPPROTO_ICMP); if (so->s == -1) { return -1; } so->so_m = m; so->so_faddr = ip->ip_dst; so->so_laddr = ip->ip_src; so->so_iptos = ip->ip_tos; so->so_type = IPPROTO_ICMP; so->so_state = SS_ISFCONNECTED; so->so_expire = curtime + SO_EXPIRE; addr.sin_family = AF_INET; addr.sin_addr = so->so_faddr; insque(so, &so->slirp->icmp); if (sendto(so->s, m->m_data + hlen, m->m_len - hlen, 0, (struct sockaddr *)&addr, sizeof(addr)) == -1) { DEBUG_MISC((dfd, "icmp_input icmp sendto tx errno = %d-%s\n", errno, strerror(errno))); icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0, strerror(errno)); icmp_detach(so); } return 0; }
/* * 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; 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; default: break; } }
/* * 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; } }
/* * sendto() a socket */ int sosendto(struct socket *so, struct mbuf *m) { int ret; struct sockaddr_in addr; DEBUG_CALL("sosendto"); DEBUG_ARG("so = %lx", (long)so); DEBUG_ARG("m = %lx", (long)m); addr.sin_family = AF_INET; if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) { /* It's an alias */ switch(ntohl(so->so_faddr.s_addr) & 0xff) { case CTL_DNS: addr.sin_addr = dns_addr; break; case CTL_ALIAS: default: addr.sin_addr = loopback_addr; break; } } else addr.sin_addr = so->so_faddr; addr.sin_port = so->so_fport; DEBUG_MISC((dfd, " sendto()ing, addr.sin_port=%d, addr.sin_addr.s_addr=%.16s\n", ntohs(addr.sin_port), inet_ntoa(addr.sin_addr))); /* Don't care what port we get */ ret = sendto(so->s, m->m_data, m->m_len, 0, (struct sockaddr *)&addr, sizeof (struct sockaddr)); 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_ISFCONNECTED; /* So that it gets select()ed */ return 0; }
/* * sendto() a socket */ int sosendto(struct socket *so, struct mbuf *m) { Slirp *slirp = so->slirp; int ret; struct sockaddr_in addr; DEBUG_CALL("sosendto"); DEBUG_ARG("so = %lx", (long)so); DEBUG_ARG("m = %lx", (long)m); addr.sin_family = 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(&addr.sin_addr) < 0) addr.sin_addr = loopback_addr; } else { addr.sin_addr = loopback_addr; } } else addr.sin_addr = so->so_faddr; addr.sin_port = so->so_fport; DEBUG_MISC((dfd, " sendto()ing, addr.sin_port=%d, addr.sin_addr.s_addr=%.16s\n", ntohs(addr.sin_port), inet_ntoa(addr.sin_addr))); /* Don't care what port we get */ ret = sendto(so->s, m->m_data, m->m_len, 0, (struct sockaddr *)&addr, sizeof (struct sockaddr)); 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; }
void slirp_add_net_forward(unsigned long dest_ip, unsigned long dest_mask, int dest_lport, int dest_hport, unsigned long redirect_ip, int redirect_port) { slirp_net_forward_init(); struct net_forward_entry *entry = malloc(sizeof(*entry)); if (entry == NULL) { DEBUG_MISC((dfd, "Unable to create new forwarding entry, malloc failed\n")); exit(-1); } entry->dest_ip = dest_ip; entry->dest_mask = dest_mask; entry->dest_lport = dest_lport; entry->dest_hport = dest_hport; entry->redirect_ip = redirect_ip; entry->redirect_port = redirect_port; QTAILQ_INSERT_TAIL(&net_forwards, entry, next); }
/* * if_input - read() the tty, do "top level" processing (ie: check for any escapes), * and pass onto (*ttyp->if_input) * * XXXXX Any zeros arriving by themselves are NOT placed into the arriving packet. */ #define INBUFF_SIZE 2048 /* XXX */ void if_input(struct ttys *ttyp) { u_char if_inbuff[INBUFF_SIZE]; int if_n; DEBUG_CALL("if_input"); DEBUG_ARG("ttyp = %lx", (long)ttyp); if_n = read(ttyp->fd, (char *)if_inbuff, INBUFF_SIZE); DEBUG_MISC((dfd, " read %d bytes\n", if_n)); if (if_n <= 0) { if (if_n == 0 || (errno != EINTR && errno != EAGAIN)) { if (ttyp->up) link_up--; tty_detached(ttyp, 0); } return; } if (if_n == 1) { if (*if_inbuff == '0') { ttyp->ones = 0; if (++ttyp->zeros >= 5) slirp_exit(0); return; } if (*if_inbuff == '1') { ttyp->zeros = 0; if (++ttyp->ones >= 5) tty_detached(ttyp, 0); return; } } ttyp->ones = ttyp->zeros = 0; (*ttyp->if_input)(ttyp, if_inbuff, if_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 = %lx", (long)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; }
/* * Process a received ICMP message. */ void icmp_input(struct mbuf *m, int hlen) { register struct icmp *icp; register struct ip *ip=mtod(m, struct ip *); int icmplen=ip->ip_len; /* int code; */ DEBUG_CALL("icmp_input"); DEBUG_ARG("m = %p", m); DEBUG_ARG("m_len = %d", m->m_len); icmpstat.icps_received++; /* * Locate icmp structure in mbuf, and check * that its not corrupted and of at least minimum length. */ if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */ icmpstat.icps_tooshort++; freeit: m_freem(m); goto end_error; } m->m_len -= hlen; m->m_data += hlen; icp = mtod(m, struct icmp *); if (cksum(m, icmplen)) { icmpstat.icps_checksum++; goto freeit; } m->m_len += hlen; m->m_data -= hlen; /* icmpstat.icps_inhist[icp->icmp_type]++; */ /* code = icp->icmp_code; */ DEBUG_ARG("icmp_type = %d", icp->icmp_type); switch (icp->icmp_type) { case ICMP_ECHO: icp->icmp_type = ICMP_ECHOREPLY; ip->ip_len += hlen; /* since ip_input subtracts this */ if (ip->ip_dst.s_addr == alias_addr.s_addr) { icmp_reflect(m); } else { struct socket *so; struct sockaddr_in addr; if ((so = socreate()) == NULL) goto freeit; if (icmp_send(so, m, hlen) == 0) return; if(udp_attach(so) == -1) { DEBUG_MISC(("icmp_input udp_attach errno = %d-%s\n", errno,strerror(errno))); sofree(so); m_free(m); goto end_error; } so->so_m = m; so->so_faddr = ip->ip_dst; so->so_fport = htons(7); so->so_laddr = ip->ip_src; so->so_lport = htons(9); so->so_iptos = ip->ip_tos; so->so_type = IPPROTO_ICMP; so->so_state = SS_ISFCONNECTED; /* Send the packet */ addr.sin_family = AF_INET; if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) { /* It's an alias */ switch(ntohl(so->so_faddr.s_addr) & 0xff) { case CTL_DNS: addr.sin_addr = dns_addr; break; case CTL_ALIAS: default: addr.sin_addr = loopback_addr; break; } } else { addr.sin_addr = so->so_faddr; } addr.sin_port = so->so_fport; if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0, (struct sockaddr *)&addr, sizeof(addr)) == -1) { DEBUG_MISC(("icmp_input udp sendto tx errno = %d-%s\n", errno,strerror(errno))); icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno)); udp_detach(so); } } /* if ip->ip_dst.s_addr == alias_addr.s_addr */ break; case ICMP_UNREACH: /* XXX? report error? close socket? */ case ICMP_TIMXCEED: case ICMP_PARAMPROB: case ICMP_SOURCEQUENCH: case ICMP_TSTAMP: case ICMP_MASKREQ: case ICMP_REDIRECT: icmpstat.icps_notsupp++; m_freem(m); break; default: icmpstat.icps_badtype++; m_freem(m); } /* swith */ end_error: /* m is m_free()'d xor put in a socket xor or given to ip_send */ return; }
/* * 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, lss, total; struct sbuf *sb = &so->so_snd; int len = sb->sb_datalen - sb->sb_cc; struct iovec iov[2]; int mss = so->so_tcpcb->t_maxseg; 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 */ len = sb->sb_datalen - sb->sb_cc; iov[0].iov_base = sb->sb_wptr; 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; } } #ifdef HAVE_READV nn = readv(so->s, (struct iovec *)iov, n); DEBUG_MISC((" ... read nn = %d bytes\n", nn)); #else nn = 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 { DEBUG_MISC((" --- soread() disconnected, nn = %d, errno = %d-%s\n", nn, errno,strerror(errno))); sofcantrcvmore(so); 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 wont (shouldn't) happen, since it didn't happen above */ if (n == 2 && nn == iov[0].iov_len) { int ret; ret = recv(so->s, iov[1].iov_base, iov[1].iov_len,0); if (ret > 0) nn += ret; } DEBUG_MISC((" ... 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; }
/* * TCP input routine, follows pages 65-76 of the * protocol specification dated September, 1981 very closely. */ void tcp_input(struct mbuf *m, int iphlen, struct socket *inso) { struct ip save_ip, *ip; register struct tcpiphdr *ti; caddr_t optp = NULL; int optlen = 0; int len, tlen, off; register struct tcpcb *tp = NULL; register int tiflags; struct socket *so = NULL; int todrop, acked, ourfinisacked, needoutput = 0; int iss = 0; u_long tiwin; int ret; struct ex_list *ex_ptr; Slirp *slirp; DEBUG_CALL("tcp_input"); DEBUG_ARGS((dfd, " m = %8lx iphlen = %2d inso = %lx\n", (long )m, iphlen, (long )inso )); /* * If called with m == 0, then we're continuing the connect */ if (m == NULL) { so = inso; slirp = so->slirp; /* Re-set a few variables */ tp = sototcpcb(so); m = so->so_m; so->so_m = NULL; ti = so->so_ti; tiwin = ti->ti_win; tiflags = ti->ti_flags; goto cont_conn; } slirp = m->slirp; /* * Get IP and TCP header together in first mbuf. * Note: IP leaves IP header in first mbuf. */ ti = mtod(m, struct tcpiphdr *); if (iphlen > sizeof(struct ip )) { ip_stripoptions(m, (struct mbuf *)0); iphlen=sizeof(struct ip ); } /* XXX Check if too short */ /* * Save a copy of the IP header in case we want restore it * for sending an ICMP error message in response. */ ip=mtod(m, struct ip *); save_ip = *ip; save_ip.ip_len+= iphlen; /* * Checksum extended TCP header and data. */ tlen = ((struct ip *)ti)->ip_len; tcpiphdr2qlink(ti)->next = tcpiphdr2qlink(ti)->prev = NULL; memset(&ti->ti_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr)); ti->ti_x1 = 0; ti->ti_len = htons((uint16_t)tlen); len = sizeof(struct ip ) + tlen; if(cksum(m, len)) { goto drop; } /* * Check that TCP offset makes sense, * pull out TCP options and adjust length. XXX */ off = ti->ti_off << 2; if (off < sizeof (struct tcphdr) || off > tlen) { goto drop; } tlen -= off; ti->ti_len = tlen; if (off > sizeof (struct tcphdr)) { optlen = off - sizeof (struct tcphdr); optp = mtod(m, caddr_t) + sizeof (struct tcpiphdr); } tiflags = ti->ti_flags; /* * Convert TCP protocol specific fields to host format. */ NTOHL(ti->ti_seq); NTOHL(ti->ti_ack); NTOHS(ti->ti_win); NTOHS(ti->ti_urp); /* * Drop TCP, IP headers and TCP options. */ m->m_data += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr); m->m_len -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr); /* * Locate pcb for segment. */ findso: so = slirp->tcp_last_so; if (so->so_fport != ti->ti_dport || so->so_lport != ti->ti_sport || so->so_laddr.s_addr != ti->ti_src.s_addr || so->so_faddr.s_addr != ti->ti_dst.s_addr) { so = solookup(&slirp->tcb, ti->ti_src, ti->ti_sport, ti->ti_dst, ti->ti_dport); if (so) slirp->tcp_last_so = so; } /* * If the state is CLOSED (i.e., TCB does not exist) then * all data in the incoming segment is discarded. * If the TCB exists but is in CLOSED state, it is embryonic, * but should either do a listen or a connect soon. * * state == CLOSED means we've done socreate() but haven't * attached it to a protocol yet... * * XXX If a TCB does not exist, and the TH_SYN flag is * the only flag set, then create a session, mark it * as if it was LISTENING, and continue... */ if (so == NULL) { if (slirp->restricted) { /* Any hostfwds will have an existing socket, so we only get here * for non-hostfwd connections. These should be dropped, unless it * happens to be a guestfwd. */ for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) { if (ex_ptr->ex_fport == ti->ti_dport && ti->ti_dst.s_addr == ex_ptr->ex_addr.s_addr) { break; } } if (!ex_ptr) { goto dropwithreset; } } if ((tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) != TH_SYN) goto dropwithreset; if ((so = socreate(slirp)) == NULL) goto dropwithreset; if (tcp_attach(so) < 0) { free(so); /* Not sofree (if it failed, it's not insqued) */ goto dropwithreset; } sbreserve(&so->so_snd, TCP_SNDSPACE); sbreserve(&so->so_rcv, TCP_RCVSPACE); so->so_laddr = ti->ti_src; so->so_lport = ti->ti_sport; so->so_faddr = ti->ti_dst; so->so_fport = ti->ti_dport; if ((so->so_iptos = tcp_tos(so)) == 0) so->so_iptos = ((struct ip *)ti)->ip_tos; tp = sototcpcb(so); tp->t_state = TCPS_LISTEN; } /* * If this is a still-connecting socket, this probably * a retransmit of the SYN. Whether it's a retransmit SYN * or something else, we nuke it. */ if (so->so_state & SS_ISFCONNECTING) goto drop; tp = sototcpcb(so); /* XXX Should never fail */ if (tp == NULL) goto dropwithreset; if (tp->t_state == TCPS_CLOSED) goto drop; tiwin = ti->ti_win; /* * Segment received on connection. * Reset idle time and keep-alive timer. */ tp->t_idle = 0; if (SO_OPTIONS) tp->t_timer[TCPT_KEEP] = TCPTV_KEEPINTVL; else tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_IDLE; /* * Process options if not in LISTEN state, * else do it below (after getting remote address). */ if (optp && tp->t_state != TCPS_LISTEN) tcp_dooptions(tp, (u_char *)optp, optlen, ti); /* * Header prediction: check for the two common cases * of a uni-directional data xfer. If the packet has * no control flags, is in-sequence, the window didn't * change and we're not retransmitting, it's a * candidate. If the length is zero and the ack moved * forward, we're the sender side of the xfer. Just * free the data acked & wake any higher level process * that was blocked waiting for space. If the length * is non-zero and the ack didn't move, we're the * receiver side. If we're getting packets in-order * (the reassembly queue is empty), add the data to * the socket buffer and note that we need a delayed ack. * * XXX Some of these tests are not needed * eg: the tiwin == tp->snd_wnd prevents many more * predictions.. with no *real* advantage.. */ if (tp->t_state == TCPS_ESTABLISHED && (tiflags & (TH_SYN|TH_FIN|TH_RST|TH_URG|TH_ACK)) == TH_ACK && ti->ti_seq == tp->rcv_nxt && tiwin && tiwin == tp->snd_wnd && tp->snd_nxt == tp->snd_max) { if (ti->ti_len == 0) { if (SEQ_GT(ti->ti_ack, tp->snd_una) && SEQ_LEQ(ti->ti_ack, tp->snd_max) && tp->snd_cwnd >= tp->snd_wnd) { /* * this is a pure ack for outstanding data. */ if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq)) tcp_xmit_timer(tp, tp->t_rtt); acked = ti->ti_ack - tp->snd_una; sbdrop(&so->so_snd, acked); tp->snd_una = ti->ti_ack; m_free(m); /* * If all outstanding data are acked, stop * retransmit timer, otherwise restart timer * using current (possibly backed-off) value. * If process is waiting for space, * wakeup/selwakeup/signal. If data * are ready to send, let tcp_output * decide between more output or persist. */ if (tp->snd_una == tp->snd_max) tp->t_timer[TCPT_REXMT] = 0; else if (tp->t_timer[TCPT_PERSIST] == 0) tp->t_timer[TCPT_REXMT] = tp->t_rxtcur; /* * This is called because sowwakeup might have * put data into so_snd. Since we don't so sowwakeup, * we don't need this.. XXX??? */ if (so->so_snd.sb_cc) (void) tcp_output(tp); return; } } else if (ti->ti_ack == tp->snd_una && tcpfrag_list_empty(tp) && ti->ti_len <= sbspace(&so->so_rcv)) { /* * this is a pure, in-sequence data packet * with nothing on the reassembly queue and * we have enough buffer space to take it. */ tp->rcv_nxt += ti->ti_len; /* * Add data to socket buffer. */ if (so->so_emu) { if (tcp_emu(so,m)) sbappend(so, m); } else sbappend(so, m); /* * If this is a short packet, then ACK now - with Nagel * congestion avoidance sender won't send more until * he gets an ACK. * * It is better to not delay acks at all to maximize * TCP throughput. See RFC 2581. */ tp->t_flags |= TF_ACKNOW; tcp_output(tp); return; } } /* header prediction */ /* * Calculate amount of space in receive window, * and then do TCP input processing. * Receive window is amount of space in rcv queue, * but not less than advertised window. */ { int win; win = sbspace(&so->so_rcv); if (win < 0) win = 0; tp->rcv_wnd = max(win, (int)(tp->rcv_adv - tp->rcv_nxt)); } switch (tp->t_state) { /* * If the state is LISTEN then ignore segment if it contains an RST. * If the segment contains an ACK then it is bad and send a RST. * If it does not contain a SYN then it is not interesting; drop it. * Don't bother responding if the destination was a broadcast. * Otherwise initialize tp->rcv_nxt, and tp->irs, select an initial * tp->iss, and send a segment: * <SEQ=ISS><ACK=RCV_NXT><CTL=SYN,ACK> * Also initialize tp->snd_nxt to tp->iss+1 and tp->snd_una to tp->iss. * Fill in remote peer address fields if not previously specified. * Enter SYN_RECEIVED state, and process any other fields of this * segment in this state. */ case TCPS_LISTEN: { if (tiflags & TH_RST) goto drop; if (tiflags & TH_ACK) goto dropwithreset; if ((tiflags & TH_SYN) == 0) goto drop; /* * This has way too many gotos... * But a bit of spaghetti code never hurt anybody :) */ /* * If this is destined for the control address, then flag to * tcp_ctl once connected, otherwise connect */ if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr && so->so_faddr.s_addr != slirp->vnameserver_addr.s_addr) { /* May be an add exec */ for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) { if(ex_ptr->ex_fport == so->so_fport && so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr) { so->so_state |= SS_CTL; break; } } if (so->so_state & SS_CTL) { goto cont_input; } } /* CTL_ALIAS: Do nothing, tcp_fconnect will be called on it */ } if (so->so_emu & EMU_NOCONNECT) { so->so_emu &= ~EMU_NOCONNECT; goto cont_input; } if ((tcp_fconnect(so) == -1) && #if defined(_WIN32) socket_error() != WSAEWOULDBLOCK #else (errno != EINPROGRESS) && (errno != EWOULDBLOCK) #endif ) { u_char code=ICMP_UNREACH_NET; DEBUG_MISC((dfd, " tcp fconnect errno = %d-%s\n", errno,strerror(errno))); if(errno == ECONNREFUSED) { /* ACK the SYN, send RST to refuse the connection */ tcp_respond(tp, ti, m, ti->ti_seq+1, (tcp_seq)0, TH_RST|TH_ACK); } else { if(errno == EHOSTUNREACH) code=ICMP_UNREACH_HOST; HTONL(ti->ti_seq); /* restore tcp header */ HTONL(ti->ti_ack); HTONS(ti->ti_win); HTONS(ti->ti_urp); m->m_data -= sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr); m->m_len += sizeof(struct tcpiphdr)+off-sizeof(struct tcphdr); *ip=save_ip; icmp_error(m, ICMP_UNREACH,code, 0,strerror(errno)); } tcp_close(tp); m_free(m); } else { /* * Haven't connected yet, save the current mbuf * and ti, and return * XXX Some OS's don't tell us whether the connect() * succeeded or not. So we must time it out. */ so->so_m = m; so->so_ti = ti; tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; tp->t_state = TCPS_SYN_RECEIVED; tcp_template(tp); } return; cont_conn: /* m==NULL * Check if the connect succeeded */ if (so->so_state & SS_NOFDREF) { tp = tcp_close(tp); goto dropwithreset; } cont_input: tcp_template(tp); if (optp) tcp_dooptions(tp, (u_char *)optp, optlen, ti); if (iss) tp->iss = iss; else tp->iss = slirp->tcp_iss; slirp->tcp_iss += TCP_ISSINCR/2; tp->irs = ti->ti_seq; tcp_sendseqinit(tp); tcp_rcvseqinit(tp); tp->t_flags |= TF_ACKNOW; tp->t_state = TCPS_SYN_RECEIVED; tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; goto trimthenstep6; } /* case TCPS_LISTEN */ /* * If the state is SYN_SENT: * if seg contains an ACK, but not for our SYN, drop the input. * if seg contains a RST, then drop the connection. * if seg does not contain SYN, then drop it. * Otherwise this is an acceptable SYN segment * initialize tp->rcv_nxt and tp->irs * if seg contains ack then advance tp->snd_una * if SYN has been acked change to ESTABLISHED else SYN_RCVD state * arrange for segment to be acked (eventually) * continue processing rest of data/controls, beginning with URG */ case TCPS_SYN_SENT: if ((tiflags & TH_ACK) && (SEQ_LEQ(ti->ti_ack, tp->iss) || SEQ_GT(ti->ti_ack, tp->snd_max))) goto dropwithreset; if (tiflags & TH_RST) { if (tiflags & TH_ACK) { tcp_drop(tp, 0); /* XXX Check t_softerror! */ } goto drop; } if ((tiflags & TH_SYN) == 0) goto drop; if (tiflags & TH_ACK) { tp->snd_una = ti->ti_ack; if (SEQ_LT(tp->snd_nxt, tp->snd_una)) tp->snd_nxt = tp->snd_una; } tp->t_timer[TCPT_REXMT] = 0; tp->irs = ti->ti_seq; tcp_rcvseqinit(tp); tp->t_flags |= TF_ACKNOW; if (tiflags & TH_ACK && SEQ_GT(tp->snd_una, tp->iss)) { soisfconnected(so); tp->t_state = TCPS_ESTABLISHED; (void) tcp_reass(tp, (struct tcpiphdr *)0, (struct mbuf *)0); /* * if we didn't have to retransmit the SYN, * use its rtt as our initial srtt & rtt var. */ if (tp->t_rtt) tcp_xmit_timer(tp, tp->t_rtt); } else tp->t_state = TCPS_SYN_RECEIVED; trimthenstep6: /* * Advance ti->ti_seq to correspond to first data byte. * If data, trim to stay within window, * dropping FIN if necessary. */ ti->ti_seq++; if (ti->ti_len > tp->rcv_wnd) { todrop = ti->ti_len - tp->rcv_wnd; m_adj(m, -todrop); ti->ti_len = tp->rcv_wnd; tiflags &= ~TH_FIN; } tp->snd_wl1 = ti->ti_seq - 1; tp->rcv_up = ti->ti_seq; goto step6; } /* switch tp->t_state */ /* * States other than LISTEN or SYN_SENT. * Check that at least some bytes of segment are within * receive window. If segment begins before rcv_nxt, * drop leading data (and SYN); if nothing left, just ack. */ todrop = tp->rcv_nxt - ti->ti_seq; if (todrop > 0) { if (tiflags & TH_SYN) { tiflags &= ~TH_SYN; ti->ti_seq++; if (ti->ti_urp > 1) ti->ti_urp--; else tiflags &= ~TH_URG; todrop--; } /* * Following if statement from Stevens, vol. 2, p. 960. */ if (todrop > ti->ti_len || (todrop == ti->ti_len && (tiflags & TH_FIN) == 0)) { /* * Any valid FIN must be to the left of the window. * At this point the FIN must be a duplicate or out * of sequence; drop it. */ tiflags &= ~TH_FIN; /* * Send an ACK to resynchronize and drop any data. * But keep on processing for RST or ACK. */ tp->t_flags |= TF_ACKNOW; todrop = ti->ti_len; } m_adj(m, todrop); ti->ti_seq += todrop; ti->ti_len -= todrop; if (ti->ti_urp > todrop) ti->ti_urp -= todrop; else { tiflags &= ~TH_URG; ti->ti_urp = 0; } } /* * If new data are received on a connection after the * user processes are gone, then RST the other end. */ if ((so->so_state & SS_NOFDREF) && tp->t_state > TCPS_CLOSE_WAIT && ti->ti_len) { tp = tcp_close(tp); goto dropwithreset; } /* * If segment ends after window, drop trailing data * (and PUSH and FIN); if nothing left, just ACK. */ todrop = (ti->ti_seq+ti->ti_len) - (tp->rcv_nxt+tp->rcv_wnd); if (todrop > 0) { if (todrop >= ti->ti_len) { /* * If a new connection request is received * while in TIME_WAIT, drop the old connection * and start over if the sequence numbers * are above the previous ones. */ if (tiflags & TH_SYN && tp->t_state == TCPS_TIME_WAIT && SEQ_GT(ti->ti_seq, tp->rcv_nxt)) { iss = tp->rcv_nxt + TCP_ISSINCR; tp = tcp_close(tp); goto findso; } /* * If window is closed can only take segments at * window edge, and have to drop data and PUSH from * incoming segments. Continue processing, but * remember to ack. Otherwise, drop segment * and ack. */ if (tp->rcv_wnd == 0 && ti->ti_seq == tp->rcv_nxt) { tp->t_flags |= TF_ACKNOW; } else { goto dropafterack; } } m_adj(m, -todrop); ti->ti_len -= todrop; tiflags &= ~(TH_PUSH|TH_FIN); } /* * If the RST bit is set examine the state: * SYN_RECEIVED STATE: * If passive open, return to LISTEN state. * If active open, inform user that connection was refused. * ESTABLISHED, FIN_WAIT_1, FIN_WAIT2, CLOSE_WAIT STATES: * Inform user that connection was reset, and close tcb. * CLOSING, LAST_ACK, TIME_WAIT STATES * Close the tcb. */ if (tiflags&TH_RST) switch (tp->t_state) { case TCPS_SYN_RECEIVED: case TCPS_ESTABLISHED: case TCPS_FIN_WAIT_1: case TCPS_FIN_WAIT_2: case TCPS_CLOSE_WAIT: tp->t_state = TCPS_CLOSED; tcp_close(tp); goto drop; case TCPS_CLOSING: case TCPS_LAST_ACK: case TCPS_TIME_WAIT: tcp_close(tp); goto drop; } /* * If a SYN is in the window, then this is an * error and we send an RST and drop the connection. */ if (tiflags & TH_SYN) { tp = tcp_drop(tp,0); goto dropwithreset; } /* * If the ACK bit is off we drop the segment and return. */ if ((tiflags & TH_ACK) == 0) goto drop; /* * Ack processing. */ switch (tp->t_state) { /* * In SYN_RECEIVED state if the ack ACKs our SYN then enter * ESTABLISHED state and continue processing, otherwise * send an RST. una<=ack<=max */ case TCPS_SYN_RECEIVED: if (SEQ_GT(tp->snd_una, ti->ti_ack) || SEQ_GT(ti->ti_ack, tp->snd_max)) goto dropwithreset; tp->t_state = TCPS_ESTABLISHED; /* * The sent SYN is ack'ed with our sequence number +1 * The first data byte already in the buffer will get * lost if no correction is made. This is only needed for * SS_CTL since the buffer is empty otherwise. * tp->snd_una++; or: */ tp->snd_una=ti->ti_ack; if (so->so_state & SS_CTL) { /* So tcp_ctl reports the right state */ ret = tcp_ctl(so); if (ret == 1) { soisfconnected(so); so->so_state &= ~SS_CTL; /* success XXX */ } else if (ret == 2) { so->so_state &= SS_PERSISTENT_MASK; so->so_state |= SS_NOFDREF; /* CTL_CMD */ } else { needoutput = 1; tp->t_state = TCPS_FIN_WAIT_1; } } else { soisfconnected(so); } (void) tcp_reass(tp, (struct tcpiphdr *)0, (struct mbuf *)0); tp->snd_wl1 = ti->ti_seq - 1; /* Avoid ack processing; snd_una==ti_ack => dup ack */ goto synrx_to_est; /* fall into ... */ /* * In ESTABLISHED state: drop duplicate ACKs; ACK out of range * ACKs. If the ack is in the range * tp->snd_una < ti->ti_ack <= tp->snd_max * then advance tp->snd_una to ti->ti_ack and drop * data from the retransmission queue. If this ACK reflects * more up to date window information we update our window information. */ case TCPS_ESTABLISHED: case TCPS_FIN_WAIT_1: case TCPS_FIN_WAIT_2: case TCPS_CLOSE_WAIT: case TCPS_CLOSING: case TCPS_LAST_ACK: case TCPS_TIME_WAIT: if (SEQ_LEQ(ti->ti_ack, tp->snd_una)) { if (ti->ti_len == 0 && tiwin == tp->snd_wnd) { DEBUG_MISC((dfd, " dup ack m = %lx so = %lx\n", (long )m, (long )so)); /* * If we have outstanding data (other than * a window probe), this is a completely * duplicate ack (ie, window info didn't * change), the ack is the biggest we've * seen and we've seen exactly our rexmt * threshold of them, assume a packet * has been dropped and retransmit it. * Kludge snd_nxt & the congestion * window so we send only this one * packet. * * We know we're losing at the current * window size so do congestion avoidance * (set ssthresh to half the current window * and pull our congestion window back to * the new ssthresh). * * Dup acks mean that packets have left the * network (they're now cached at the receiver) * so bump cwnd by the amount in the receiver * to keep a constant cwnd packets in the * network. */ if (tp->t_timer[TCPT_REXMT] == 0 || ti->ti_ack != tp->snd_una) tp->t_dupacks = 0; else if (++tp->t_dupacks == TCPREXMTTHRESH) { tcp_seq onxt = tp->snd_nxt; u_int win = min(tp->snd_wnd, tp->snd_cwnd) / 2 / tp->t_maxseg; if (win < 2) win = 2; tp->snd_ssthresh = win * tp->t_maxseg; tp->t_timer[TCPT_REXMT] = 0; tp->t_rtt = 0; tp->snd_nxt = ti->ti_ack; tp->snd_cwnd = tp->t_maxseg; (void) tcp_output(tp); tp->snd_cwnd = tp->snd_ssthresh + tp->t_maxseg * tp->t_dupacks; if (SEQ_GT(onxt, tp->snd_nxt)) tp->snd_nxt = onxt; goto drop; } else if (tp->t_dupacks > TCPREXMTTHRESH) { tp->snd_cwnd += tp->t_maxseg; (void) tcp_output(tp); goto drop; } } else tp->t_dupacks = 0; break; } synrx_to_est: /* * If the congestion window was inflated to account * for the other side's cached packets, retract it. */ if (tp->t_dupacks > TCPREXMTTHRESH && tp->snd_cwnd > tp->snd_ssthresh) tp->snd_cwnd = tp->snd_ssthresh; tp->t_dupacks = 0; if (SEQ_GT(ti->ti_ack, tp->snd_max)) { goto dropafterack; } acked = ti->ti_ack - tp->snd_una; /* * If transmit timer is running and timed sequence * number was acked, update smoothed round trip time. * Since we now have an rtt measurement, cancel the * timer backoff (cf., Phil Karn's retransmit alg.). * Recompute the initial retransmit timer. */ if (tp->t_rtt && SEQ_GT(ti->ti_ack, tp->t_rtseq)) tcp_xmit_timer(tp,tp->t_rtt); /* * If all outstanding data is acked, stop retransmit * timer and remember to restart (more output or persist). * If there is more data to be acked, restart retransmit * timer, using current (possibly backed-off) value. */ if (ti->ti_ack == tp->snd_max) { tp->t_timer[TCPT_REXMT] = 0; needoutput = 1; } else if (tp->t_timer[TCPT_PERSIST] == 0) tp->t_timer[TCPT_REXMT] = tp->t_rxtcur; /* * When new data is acked, open the congestion window. * If the window gives us less than ssthresh packets * in flight, open exponentially (maxseg per packet). * Otherwise open linearly: maxseg per window * (maxseg^2 / cwnd per packet). */ { register u_int cw = tp->snd_cwnd; register u_int incr = tp->t_maxseg; if (cw > tp->snd_ssthresh) incr = incr * incr / cw; tp->snd_cwnd = min(cw + incr, TCP_MAXWIN<<tp->snd_scale); } if (acked > so->so_snd.sb_cc) { tp->snd_wnd -= so->so_snd.sb_cc; sbdrop(&so->so_snd, (int )so->so_snd.sb_cc); ourfinisacked = 1; } else { sbdrop(&so->so_snd, acked); tp->snd_wnd -= acked; ourfinisacked = 0; } tp->snd_una = ti->ti_ack; if (SEQ_LT(tp->snd_nxt, tp->snd_una)) tp->snd_nxt = tp->snd_una; switch (tp->t_state) { /* * In FIN_WAIT_1 STATE in addition to the processing * for the ESTABLISHED state if our FIN is now acknowledged * then enter FIN_WAIT_2. */ case TCPS_FIN_WAIT_1: if (ourfinisacked) { /* * If we can't receive any more * data, then closing user can proceed. * Starting the timer is contrary to the * specification, but if we don't get a FIN * we'll hang forever. */ if (so->so_state & SS_FCANTRCVMORE) { tp->t_timer[TCPT_2MSL] = TCP_MAXIDLE; } tp->t_state = TCPS_FIN_WAIT_2; } break; /* * In CLOSING STATE in addition to the processing for * the ESTABLISHED state if the ACK acknowledges our FIN * then enter the TIME-WAIT state, otherwise ignore * the segment. */ case TCPS_CLOSING: if (ourfinisacked) { tp->t_state = TCPS_TIME_WAIT; tcp_canceltimers(tp); tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; } break; /* * In LAST_ACK, we may still be waiting for data to drain * and/or to be acked, as well as for the ack of our FIN. * If our FIN is now acknowledged, delete the TCB, * enter the closed state and return. */ case TCPS_LAST_ACK: if (ourfinisacked) { tcp_close(tp); goto drop; } break; /* * In TIME_WAIT state the only thing that should arrive * is a retransmission of the remote FIN. Acknowledge * it and restart the finack timer. */ case TCPS_TIME_WAIT: tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; goto dropafterack; } } /* switch(tp->t_state) */ step6: /* * Update window information. * Don't look at window if no ACK: TAC's send garbage on first SYN. */ if ((tiflags & TH_ACK) && (SEQ_LT(tp->snd_wl1, ti->ti_seq) || (tp->snd_wl1 == ti->ti_seq && (SEQ_LT(tp->snd_wl2, ti->ti_ack) || (tp->snd_wl2 == ti->ti_ack && tiwin > tp->snd_wnd))))) { tp->snd_wnd = tiwin; tp->snd_wl1 = ti->ti_seq; tp->snd_wl2 = ti->ti_ack; if (tp->snd_wnd > tp->max_sndwnd) tp->max_sndwnd = tp->snd_wnd; needoutput = 1; } /* * Process segments with URG. */ if ((tiflags & TH_URG) && ti->ti_urp && TCPS_HAVERCVDFIN(tp->t_state) == 0) { /* * This is a kludge, but if we receive and accept * random urgent pointers, we'll crash in * soreceive. It's hard to imagine someone * actually wanting to send this much urgent data. */ if (ti->ti_urp + so->so_rcv.sb_cc > so->so_rcv.sb_datalen) { ti->ti_urp = 0; tiflags &= ~TH_URG; goto dodata; } /* * If this segment advances the known urgent pointer, * then mark the data stream. This should not happen * in CLOSE_WAIT, CLOSING, LAST_ACK or TIME_WAIT STATES since * a FIN has been received from the remote side. * In these states we ignore the URG. * * According to RFC961 (Assigned Protocols), * the urgent pointer points to the last octet * of urgent data. We continue, however, * to consider it to indicate the first octet * of data past the urgent section as the original * spec states (in one of two places). */ if (SEQ_GT(ti->ti_seq+ti->ti_urp, tp->rcv_up)) { tp->rcv_up = ti->ti_seq + ti->ti_urp; so->so_urgc = so->so_rcv.sb_cc + (tp->rcv_up - tp->rcv_nxt); /* -1; */ tp->rcv_up = ti->ti_seq + ti->ti_urp; } } else /* * If no out of band data is expected, * pull receive urgent pointer along * with the receive window. */ if (SEQ_GT(tp->rcv_nxt, tp->rcv_up)) tp->rcv_up = tp->rcv_nxt; dodata: /* * If this is a small packet, then ACK now - with Nagel * congestion avoidance sender won't send more until * he gets an ACK. */ if (ti->ti_len && (unsigned)ti->ti_len <= 5 && ((struct tcpiphdr_2 *)ti)->first_char == (char)27) { tp->t_flags |= TF_ACKNOW; } /* * Process the segment text, merging it into the TCP sequencing queue, * and arranging for acknowledgment of receipt if necessary. * This process logically involves adjusting tp->rcv_wnd as data * is presented to the user (this happens in tcp_usrreq.c, * case PRU_RCVD). If a FIN has already been received on this * connection then we just ignore the text. */ if ((ti->ti_len || (tiflags&TH_FIN)) && TCPS_HAVERCVDFIN(tp->t_state) == 0) { TCP_REASS(tp, ti, m, so, tiflags); } else { m_free(m); tiflags &= ~TH_FIN; } /* * If FIN is received ACK the FIN and let the user know * that the connection is closing. */ if (tiflags & TH_FIN) { if (TCPS_HAVERCVDFIN(tp->t_state) == 0) { /* * If we receive a FIN we can't send more data, * set it SS_FDRAIN * Shutdown the socket if there is no rx data in the * buffer. * soread() is called on completion of shutdown() and * will got to TCPS_LAST_ACK, and use tcp_output() * to send the FIN. */ sofwdrain(so); tp->t_flags |= TF_ACKNOW; tp->rcv_nxt++; } switch (tp->t_state) { /* * In SYN_RECEIVED and ESTABLISHED STATES * enter the CLOSE_WAIT state. */ case TCPS_SYN_RECEIVED: case TCPS_ESTABLISHED: if(so->so_emu == EMU_CTL) /* no shutdown on socket */ tp->t_state = TCPS_LAST_ACK; else tp->t_state = TCPS_CLOSE_WAIT; break; /* * If still in FIN_WAIT_1 STATE FIN has not been acked so * enter the CLOSING state. */ case TCPS_FIN_WAIT_1: tp->t_state = TCPS_CLOSING; break; /* * In FIN_WAIT_2 state enter the TIME_WAIT state, * starting the time-wait timer, turning off the other * standard timers. */ case TCPS_FIN_WAIT_2: tp->t_state = TCPS_TIME_WAIT; tcp_canceltimers(tp); tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; break; /* * In TIME_WAIT state restart the 2 MSL time_wait timer. */ case TCPS_TIME_WAIT: tp->t_timer[TCPT_2MSL] = 2 * TCPTV_MSL; break; } } /* * Return any desired output. */ if (needoutput || (tp->t_flags & TF_ACKNOW)) { (void) tcp_output(tp); } return; dropafterack: /* * Generate an ACK dropping incoming segment if it occupies * sequence space, where the ACK reflects our state. */ if (tiflags & TH_RST) goto drop; m_free(m); tp->t_flags |= TF_ACKNOW; (void) tcp_output(tp); return; dropwithreset: /* reuses m if m!=NULL, m_free() unnecessary */ if (tiflags & TH_ACK) tcp_respond(tp, ti, m, (tcp_seq)0, ti->ti_ack, TH_RST); else { if (tiflags & TH_SYN) ti->ti_len++; tcp_respond(tp, ti, m, ti->ti_seq+ti->ti_len, (tcp_seq)0, TH_RST|TH_ACK); } return; drop: /* * Drop space held by incoming segment and return. */ m_free(m); }
void udp_input(register struct mbuf *m, int iphlen) { register struct ip *ip; register struct udphdr *uh; /* struct 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); STAT(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, (struct mbuf *)0); iphlen = sizeof(struct ip); } /* * Get IP and UDP header together in first mbuf. */ ip = mtod(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) { STAT(udpstat.udps_badlen++); 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 (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))) { STAT(udpstat.udps_badsum++); goto bad; } } /* * handle DHCP/BOOTP */ if (ntohs(uh->uh_dport) == BOOTP_SERVER) { bootp_input(m); goto bad; } if (slirp_restrict) goto bad; /* * handle TFTP */ if (ntohs(uh->uh_dport) == TFTP_SERVER) { tftp_input(m); goto bad; } /* * Locate pcb for datagram. */ so = udp_last_so; if (so->so_lport != uh->uh_sport || so->so_laddr.s_addr != ip->ip_src.s_addr) { struct socket *tmp; for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next) { if (tmp->so_lport == uh->uh_sport && tmp->so_laddr.s_addr == ip->ip_src.s_addr) { tmp->so_faddr.s_addr = ip->ip_dst.s_addr; tmp->so_fport = uh->uh_dport; so = tmp; break; } } if (tmp == &udb) { so = NULL; } else { STAT(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,strerror(errno))); sofree(so); goto bad; } /* * Setup fields */ /* udp_last_so = so; */ 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_faddr = ip->ip_dst; /* XXX */ so->so_fport = 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,strerror(errno))); icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno)); } 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_freem(m); /* if (opts) m_freem(opts); */ return; }
/* * sendto() a socket */ int sosendto(struct socket *so, struct mbuf *m) { int ret; SockAddress addr; uint32_t addr_ip; uint16_t addr_port; DEBUG_CALL("sosendto"); DEBUG_ARG("so = %lx", (long)so); DEBUG_ARG("m = %lx", (long)m); if ((so->so_faddr_ip & 0xffffff00) == special_addr_ip) { /* It's an alias */ int low = so->so_faddr_ip & 0xff; if ( CTL_IS_DNS(low) ) addr_ip = dns_addr[low - CTL_DNS]; else addr_ip = loopback_addr_ip; } else addr_ip = so->so_faddr_ip; addr_port = so->so_faddr_port; /* * test for generic forwarding; this function replaces the arguments * only on success */ unsigned long faddr = addr_ip; int fport = addr_port; if (slirp_should_net_forward(faddr, fport, &faddr, &fport)) { time_t timestamp = time(NULL); slirp_drop_log( "Redirected UDP: src: 0x%08lx:0x%04x org dst: 0x%08lx:0x%04x " "new dst: 0x%08lx:0x%04x %ld\n", so->so_laddr_ip, so->so_laddr_port, addr_ip, addr_port, faddr, fport, timestamp ); } addr_ip = faddr; addr_port = fport; sock_address_init_inet(&addr, addr_ip, addr_port); DEBUG_MISC((dfd, " sendto()ing, addr.sin_port=%d, addr.sin_addr.s_addr=%08x\n", addr_port, addr_ip)); /* Don't care what port we get */ ret = socket_sendto(so->s, m->m_data, m->m_len,&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_ISFCONNECTED; /* So that it gets select()ed */ return 0; }
void icmp_input(struct mbuf *m, int hlen) { register struct icmp *icp; register struct ip *ip=mtod(m, struct ip *); int icmplen=ip->ip_len; /* int code; */ DEBUG_CALL("icmp_input"); DEBUG_ARG("m = %lx", (long )m); DEBUG_ARG("m_len = %d", m->m_len); STAT(icmpstat.icps_received++); /* * Locate icmp structure in mbuf, and check * that its not corrupted and of at least minimum length. */ if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */ STAT(icmpstat.icps_tooshort++); freeit: m_freem(m); goto end_error; } m->m_len -= hlen; m->m_data += hlen; icp = mtod(m, struct icmp *); if (cksum(m, icmplen)) { STAT(icmpstat.icps_checksum++); goto freeit; } m->m_len += hlen; m->m_data -= hlen; /* icmpstat.icps_inhist[icp->icmp_type]++; */ /* code = icp->icmp_code; */ DEBUG_ARG("icmp_type = %d", icp->icmp_type); switch (icp->icmp_type) { case ICMP_ECHO: icp->icmp_type = ICMP_ECHOREPLY; ip->ip_len += hlen; /* since ip_input subtracts this */ if (ip_geth(ip->ip_dst) == alias_addr_ip) { icmp_reflect(m); } else { struct socket *so; SockAddress addr; uint32_t addr_ip; uint16_t addr_port; if ((so = socreate()) == NULL) goto freeit; if(udp_attach(so) == -1) { DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n", errno,errno_str)); sofree(so); m_free(m); goto end_error; } so->so_m = m; so->so_faddr_ip = ip_geth(ip->ip_dst); so->so_faddr_port = 7; so->so_laddr_ip = ip_geth(ip->ip_src); so->so_laddr_port = 9; so->so_iptos = ip->ip_tos; so->so_type = IPPROTO_ICMP; so->so_state = SS_ISFCONNECTED; /* Send the packet */ if ((so->so_faddr_ip & 0xffffff00) == special_addr_ip) { /* It's an alias */ int low = so->so_faddr_ip & 0xff; if (low >= CTL_DNS && low < CTL_DNS + dns_addr_count) addr_ip = dns_addr[low - CTL_DNS]; else addr_ip = loopback_addr_ip; } else { addr_ip = so->so_faddr_ip; } addr_port = so->so_faddr_port; sock_address_init_inet( &addr, addr_ip, addr_port ); if(socket_sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), &addr) < 0) { DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n", errno,errno_str)); icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,errno_str); udp_detach(so); } } /* if ip->ip_dst.s_addr == alias_addr.s_addr */ break; case ICMP_UNREACH: /* XXX? report error? close socket? */ case ICMP_TIMXCEED: case ICMP_PARAMPROB: case ICMP_SOURCEQUENCH: case ICMP_TSTAMP: case ICMP_MASKREQ: case ICMP_REDIRECT: STAT(icmpstat.icps_notsupp++); m_freem(m); break; default: STAT(icmpstat.icps_badtype++); m_freem(m); } /* swith */ end_error: /* m is m_free()'d xor put in a socket xor or given to ip_send */ return; }
void icmp_error(struct mbuf *msrc, u_char type, u_char code, int minsize, const char *message) { unsigned hlen, shlen, s_ip_len; register struct ip *ip; register struct icmp *icp; register struct mbuf *m; DEBUG_CALL("icmp_error"); DEBUG_ARG("msrc = %lx", (long )msrc); DEBUG_ARG("msrc_len = %d", msrc->m_len); if(type!=ICMP_UNREACH && type!=ICMP_TIMXCEED) goto end_error; /* check msrc */ if(!msrc) goto end_error; ip = mtod(msrc, struct ip *); #ifdef DEBUG { char bufa[20], bufb[20]; strcpy(bufa, inet_ntoa(ip->ip_src)); strcpy(bufb, inet_ntoa(ip->ip_dst)); DEBUG_MISC((dfd, " %.16s to %.16s\n", bufa, bufb)); } #endif if(ip->ip_off & IP_OFFMASK) goto end_error; /* Only reply to fragment 0 */ /* Do not reply to source-only IPs */ if ((ip->ip_src.s_addr & htonl(~(0xf << 28))) == 0) { goto end_error; } shlen=ip->ip_hl << 2; s_ip_len=ip->ip_len; if(ip->ip_p == IPPROTO_ICMP) { icp = (struct icmp *)((char *)ip + shlen); /* * Assume any unknown ICMP type is an error. This isn't * specified by the RFC, but think about it.. */ if(icp->icmp_type>18 || icmp_flush[icp->icmp_type]) goto end_error; } /* make a copy */ m = m_get(msrc->slirp); if (!m) { goto end_error; } { int new_m_size; new_m_size=sizeof(struct ip )+ICMP_MINLEN+msrc->m_len+ICMP_MAXDATALEN; if(new_m_size>m->m_size) m_inc(m, new_m_size); } memcpy(m->m_data, msrc->m_data, msrc->m_len); m->m_len = msrc->m_len; /* copy msrc to m */ /* make the header of the reply packet */ ip = mtod(m, struct ip *); hlen= sizeof(struct ip ); /* no options in reply */ /* fill in icmp */ m->m_data += hlen; m->m_len -= hlen; icp = mtod(m, struct icmp *); if(minsize) s_ip_len=shlen+ICMP_MINLEN; /* return header+8b only */ else if(s_ip_len>ICMP_MAXDATALEN) /* maximum size */ s_ip_len=ICMP_MAXDATALEN; m->m_len=ICMP_MINLEN+s_ip_len; /* 8 bytes ICMP header */ /* min. size = 8+sizeof(struct ip)+8 */ icp->icmp_type = type; icp->icmp_code = code; icp->icmp_id = 0; icp->icmp_seq = 0; memcpy(&icp->icmp_ip, msrc->m_data, s_ip_len); /* report the ip packet */ HTONS(icp->icmp_ip.ip_len); HTONS(icp->icmp_ip.ip_id); HTONS(icp->icmp_ip.ip_off); #ifdef DEBUG if(message) { /* DEBUG : append message to ICMP packet */ int message_len; char *cpnt; message_len=strlen(message); if(message_len>ICMP_MAXDATALEN) message_len=ICMP_MAXDATALEN; cpnt=(char *)m->m_data+m->m_len; memcpy(cpnt, message, message_len); m->m_len+=message_len; } #endif icp->icmp_cksum = 0; icp->icmp_cksum = cksum(m, m->m_len); m->m_data -= hlen; m->m_len += hlen; /* fill in ip */ ip->ip_hl = hlen >> 2; ip->ip_len = m->m_len; ip->ip_tos=((ip->ip_tos & 0x1E) | 0xC0); /* high priority for errors */ ip->ip_ttl = MAXTTL; ip->ip_p = IPPROTO_ICMP; ip->ip_dst = ip->ip_src; /* ip adresses */ ip->ip_src = m->slirp->vhost_addr; (void ) ip_output((struct socket *)NULL, m); end_error: return; }
/* * recvfrom() a UDP socket */ void sorecvfrom(struct socket *so) { struct sockaddr_in addr; socklen_t addrlen = sizeof(struct sockaddr_in); DEBUG_CALL("sorecvfrom"); DEBUG_ARG("so = %lx", (long)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_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; } m->m_data += IF_MAXLINKHDR; /* * 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) { u_char 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_error(so->so_m, ICMP_UNREACH,code, 0,strerror(errno)); 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, done by udp_output */ udp_output(so, m, &addr); } /* rx error */ } /* if ping packet */ }
/* * Process a received ICMP message. */ void icmp_input(struct mbuf *m, int hlen) { register struct icmp *icp; register struct ip *ip=mtod(m, struct ip *); int icmplen=ip->ip_len; Slirp *slirp = m->slirp; DEBUG_CALL("icmp_input"); DEBUG_ARG("m = %lx", (long )m); DEBUG_ARG("m_len = %d", m->m_len); /* * Locate icmp structure in mbuf, and check * that its not corrupted and of at least minimum length. */ if (icmplen < ICMP_MINLEN) { /* min 8 bytes payload */ freeit: m_free(m); goto end_error; } m->m_len -= hlen; m->m_data += hlen; icp = mtod(m, struct icmp *); if (cksum(m, icmplen)) { goto freeit; } m->m_len += hlen; m->m_data -= hlen; DEBUG_ARG("icmp_type = %d", icp->icmp_type); switch (icp->icmp_type) { case ICMP_ECHO: ip->ip_len += hlen; /* since ip_input subtracts this */ if (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) { icmp_reflect(m); } else if (slirp->restricted) { goto freeit; } else { struct socket *so; struct sockaddr_in addr; if ((so = socreate(slirp)) == NULL) goto freeit; if (icmp_send(so, m, hlen) == 0) { return; } if(udp_attach(so) == -1) { DEBUG_MISC((dfd,"icmp_input udp_attach errno = %d-%s\n", errno,strerror(errno))); sofree(so); m_free(m); goto end_error; } so->so_m = m; so->so_faddr = ip->ip_dst; so->so_fport = htons(7); so->so_laddr = ip->ip_src; so->so_lport = htons(9); so->so_iptos = ip->ip_tos; so->so_type = IPPROTO_ICMP; so->so_state = SS_ISFCONNECTED; /* Send the packet */ addr.sin_family = 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(&addr.sin_addr) < 0) addr.sin_addr = loopback_addr; } else { addr.sin_addr = loopback_addr; } } else { addr.sin_addr = so->so_faddr; } addr.sin_port = so->so_fport; if(sendto(so->s, icmp_ping_msg, strlen(icmp_ping_msg), 0, (struct sockaddr *)&addr, sizeof(addr)) == -1) { DEBUG_MISC((dfd,"icmp_input udp sendto tx errno = %d-%s\n", errno,strerror(errno))); icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno)); udp_detach(so); } } /* if ip->ip_dst.s_addr == alias_addr.s_addr */ break; case ICMP_UNREACH: /* XXX? report error? close socket? */ case ICMP_TIMXCEED: case ICMP_PARAMPROB: case ICMP_SOURCEQUENCH: case ICMP_TSTAMP: case ICMP_MASKREQ: case ICMP_REDIRECT: m_free(m); break; default: m_free(m); } /* swith */ end_error: /* m is m_free()'d xor put in a socket xor or given to ip_send */ return; }
/* * 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 */ }