| #include "slirp.h" |
| |
| /* host address */ |
| struct in_addr our_addr; |
| /* host dns address */ |
| struct in_addr dns_addr; |
| /* host loopback address */ |
| struct in_addr loopback_addr; |
| |
| /* address for slirp virtual addresses */ |
| struct in_addr special_addr; |
| |
| const uint8_t special_ethaddr[6] = { |
| 0x52, 0x54, 0x00, 0x12, 0x35, 0x00 |
| }; |
| |
| uint8_t client_ethaddr[6]; |
| |
| int do_slowtimo; |
| int link_up; |
| struct timeval tt; |
| FILE *lfd; |
| |
| /* XXX: suppress those select globals */ |
| fd_set *global_readfds, *global_writefds, *global_xfds; |
| |
| #ifdef _WIN32 |
| |
| static int get_dns_addr(struct in_addr *pdns_addr) |
| { |
| /* XXX: add it */ |
| return -1; |
| } |
| |
| #else |
| |
| static int get_dns_addr(struct in_addr *pdns_addr) |
| { |
| char buff[512]; |
| char buff2[256]; |
| FILE *f; |
| int found = 0; |
| struct in_addr tmp_addr; |
| |
| f = fopen("/etc/resolv.conf", "r"); |
| if (!f) |
| return -1; |
| |
| lprint("IP address of your DNS(s): "); |
| while (fgets(buff, 512, f) != NULL) { |
| if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) { |
| if (!inet_aton(buff2, &tmp_addr)) |
| continue; |
| if (tmp_addr.s_addr == loopback_addr.s_addr) |
| tmp_addr = our_addr; |
| /* If it's the first one, set it to dns_addr */ |
| if (!found) |
| *pdns_addr = tmp_addr; |
| else |
| lprint(", "); |
| if (++found > 3) { |
| lprint("(more)"); |
| break; |
| } else |
| lprint("%s", inet_ntoa(tmp_addr)); |
| } |
| } |
| if (!found) |
| return -1; |
| return 0; |
| } |
| |
| #endif |
| |
| void slirp_init(void) |
| { |
| debug_init("/tmp/slirp.log", DEBUG_DEFAULT); |
| |
| link_up = 1; |
| |
| if_init(); |
| ip_init(); |
| |
| /* Initialise mbufs *after* setting the MTU */ |
| m_init(); |
| |
| /* set default addresses */ |
| getouraddr(); |
| inet_aton("127.0.0.1", &loopback_addr); |
| |
| if (get_dns_addr(&dns_addr) < 0) { |
| fprintf(stderr, "Could not get DNS address\n"); |
| exit(1); |
| } |
| |
| inet_aton(CTL_SPECIAL, &special_addr); |
| } |
| |
| #define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED) |
| #define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED) |
| #define UPD_NFDS(x) if (nfds < (x)) nfds = (x) |
| |
| /* |
| * curtime kept to an accuracy of 1ms |
| */ |
| static void updtime(void) |
| { |
| gettimeofday(&tt, 0); |
| |
| curtime = (u_int)tt.tv_sec * (u_int)1000; |
| curtime += (u_int)tt.tv_usec / (u_int)1000; |
| |
| if ((tt.tv_usec % 1000) >= 500) |
| curtime++; |
| } |
| |
| void slirp_select_fill(int *pnfds, |
| fd_set *readfds, fd_set *writefds, fd_set *xfds) |
| { |
| struct socket *so, *so_next; |
| struct timeval timeout; |
| int nfds; |
| int tmp_time; |
| |
| /* fail safe */ |
| global_readfds = NULL; |
| global_writefds = NULL; |
| global_xfds = NULL; |
| |
| nfds = *pnfds; |
| /* |
| * First, TCP sockets |
| */ |
| do_slowtimo = 0; |
| if (link_up) { |
| /* |
| * *_slowtimo needs calling if there are IP fragments |
| * in the fragment queue, or there are TCP connections active |
| */ |
| do_slowtimo = ((tcb.so_next != &tcb) || |
| ((struct ipasfrag *)&ipq != (struct ipasfrag *)ipq.next)); |
| |
| for (so = tcb.so_next; so != &tcb; so = so_next) { |
| so_next = so->so_next; |
| |
| /* |
| * See if we need a tcp_fasttimo |
| */ |
| if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK) |
| time_fasttimo = curtime; /* Flag when we want a fasttimo */ |
| |
| /* |
| * NOFDREF can include still connecting to local-host, |
| * newly socreated() sockets etc. Don't want to select these. |
| */ |
| if (so->so_state & SS_NOFDREF || so->s == -1) |
| continue; |
| |
| /* |
| * Set for reading sockets which are accepting |
| */ |
| if (so->so_state & SS_FACCEPTCONN) { |
| FD_SET(so->s, readfds); |
| UPD_NFDS(so->s); |
| continue; |
| } |
| |
| /* |
| * Set for writing sockets which are connecting |
| */ |
| if (so->so_state & SS_ISFCONNECTING) { |
| FD_SET(so->s, writefds); |
| UPD_NFDS(so->s); |
| continue; |
| } |
| |
| /* |
| * Set for writing if we are connected, can send more, and |
| * we have something to send |
| */ |
| if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) { |
| FD_SET(so->s, writefds); |
| UPD_NFDS(so->s); |
| } |
| |
| /* |
| * Set for reading (and urgent data) if we are connected, can |
| * receive more, and we have room for it XXX /2 ? |
| */ |
| if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) { |
| FD_SET(so->s, readfds); |
| FD_SET(so->s, xfds); |
| UPD_NFDS(so->s); |
| } |
| } |
| |
| /* |
| * UDP sockets |
| */ |
| for (so = udb.so_next; so != &udb; so = so_next) { |
| so_next = so->so_next; |
| |
| /* |
| * See if it's timed out |
| */ |
| if (so->so_expire) { |
| if (so->so_expire <= curtime) { |
| udp_detach(so); |
| continue; |
| } else |
| do_slowtimo = 1; /* Let socket expire */ |
| } |
| |
| /* |
| * When UDP packets are received from over the |
| * link, they're sendto()'d straight away, so |
| * no need for setting for writing |
| * Limit the number of packets queued by this session |
| * to 4. Note that even though we try and limit this |
| * to 4 packets, the session could have more queued |
| * if the packets needed to be fragmented |
| * (XXX <= 4 ?) |
| */ |
| if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) { |
| FD_SET(so->s, readfds); |
| UPD_NFDS(so->s); |
| } |
| } |
| } |
| |
| /* |
| * Setup timeout to use minimum CPU usage, especially when idle |
| */ |
| |
| /* |
| * First, see the timeout needed by *timo |
| */ |
| timeout.tv_sec = 0; |
| timeout.tv_usec = -1; |
| /* |
| * If a slowtimo is needed, set timeout to 500ms from the last |
| * slow timeout. If a fast timeout is needed, set timeout within |
| * 200ms of when it was requested. |
| */ |
| if (do_slowtimo) { |
| /* XXX + 10000 because some select()'s aren't that accurate */ |
| timeout.tv_usec = ((500 - (curtime - last_slowtimo)) * 1000) + 10000; |
| if (timeout.tv_usec < 0) |
| timeout.tv_usec = 0; |
| else if (timeout.tv_usec > 510000) |
| timeout.tv_usec = 510000; |
| |
| /* Can only fasttimo if we also slowtimo */ |
| if (time_fasttimo) { |
| tmp_time = (200 - (curtime - time_fasttimo)) * 1000; |
| if (tmp_time < 0) |
| tmp_time = 0; |
| |
| /* Choose the smallest of the 2 */ |
| if (tmp_time < timeout.tv_usec) |
| timeout.tv_usec = (u_int)tmp_time; |
| } |
| } |
| *pnfds = nfds; |
| } |
| |
| void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds) |
| { |
| struct socket *so, *so_next; |
| int ret; |
| |
| global_readfds = readfds; |
| global_writefds = writefds; |
| global_xfds = xfds; |
| |
| /* Update time */ |
| updtime(); |
| |
| /* |
| * See if anything has timed out |
| */ |
| if (link_up) { |
| if (time_fasttimo && ((curtime - time_fasttimo) >= 199)) { |
| tcp_fasttimo(); |
| time_fasttimo = 0; |
| } |
| if (do_slowtimo && ((curtime - last_slowtimo) >= 499)) { |
| ip_slowtimo(); |
| tcp_slowtimo(); |
| last_slowtimo = curtime; |
| } |
| } |
| |
| /* |
| * Check sockets |
| */ |
| if (link_up) { |
| /* |
| * Check TCP sockets |
| */ |
| for (so = tcb.so_next; so != &tcb; so = so_next) { |
| so_next = so->so_next; |
| |
| /* |
| * FD_ISSET is meaningless on these sockets |
| * (and they can crash the program) |
| */ |
| if (so->so_state & SS_NOFDREF || so->s == -1) |
| continue; |
| |
| /* |
| * Check for URG data |
| * This will soread as well, so no need to |
| * test for readfds below if this succeeds |
| */ |
| if (FD_ISSET(so->s, xfds)) |
| sorecvoob(so); |
| /* |
| * Check sockets for reading |
| */ |
| else if (FD_ISSET(so->s, readfds)) { |
| /* |
| * Check for incoming connections |
| */ |
| if (so->so_state & SS_FACCEPTCONN) { |
| tcp_connect(so); |
| continue; |
| } /* else */ |
| ret = soread(so); |
| |
| /* Output it if we read something */ |
| if (ret > 0) |
| tcp_output(sototcpcb(so)); |
| } |
| |
| /* |
| * Check sockets for writing |
| */ |
| if (FD_ISSET(so->s, writefds)) { |
| /* |
| * Check for non-blocking, still-connecting sockets |
| */ |
| if (so->so_state & SS_ISFCONNECTING) { |
| /* Connected */ |
| so->so_state &= ~SS_ISFCONNECTING; |
| |
| ret = write(so->s, &ret, 0); |
| if (ret < 0) { |
| /* XXXXX Must fix, zero bytes is a NOP */ |
| if (errno == EAGAIN || errno == EWOULDBLOCK || |
| errno == EINPROGRESS || errno == ENOTCONN) |
| continue; |
| |
| /* else failed */ |
| so->so_state = SS_NOFDREF; |
| } |
| /* else so->so_state &= ~SS_ISFCONNECTING; */ |
| |
| /* |
| * Continue tcp_input |
| */ |
| tcp_input((struct mbuf *)NULL, sizeof(struct ip), so); |
| /* continue; */ |
| } else |
| ret = sowrite(so); |
| /* |
| * XXXXX If we wrote something (a lot), there |
| * could be a need for a window update. |
| * In the worst case, the remote will send |
| * a window probe to get things going again |
| */ |
| } |
| |
| /* |
| * Probe a still-connecting, non-blocking socket |
| * to check if it's still alive |
| */ |
| #ifdef PROBE_CONN |
| if (so->so_state & SS_ISFCONNECTING) { |
| ret = read(so->s, (char *)&ret, 0); |
| |
| if (ret < 0) { |
| /* XXX */ |
| if (errno == EAGAIN || errno == EWOULDBLOCK || |
| errno == EINPROGRESS || errno == ENOTCONN) |
| continue; /* Still connecting, continue */ |
| |
| /* else failed */ |
| so->so_state = SS_NOFDREF; |
| |
| /* tcp_input will take care of it */ |
| } else { |
| ret = write(so->s, &ret, 0); |
| if (ret < 0) { |
| /* XXX */ |
| if (errno == EAGAIN || errno == EWOULDBLOCK || |
| errno == EINPROGRESS || errno == ENOTCONN) |
| continue; |
| /* else failed */ |
| so->so_state = SS_NOFDREF; |
| } else |
| so->so_state &= ~SS_ISFCONNECTING; |
| |
| } |
| tcp_input((struct mbuf *)NULL, sizeof(struct ip),so); |
| } /* SS_ISFCONNECTING */ |
| #endif |
| } |
| |
| /* |
| * Now UDP sockets. |
| * Incoming packets are sent straight away, they're not buffered. |
| * Incoming UDP data isn't buffered either. |
| */ |
| for (so = udb.so_next; so != &udb; so = so_next) { |
| so_next = so->so_next; |
| |
| if (so->s != -1 && FD_ISSET(so->s, readfds)) { |
| sorecvfrom(so); |
| } |
| } |
| } |
| |
| /* |
| * See if we can start outputting |
| */ |
| if (if_queued && link_up) |
| if_start(); |
| } |
| |
| #define ETH_ALEN 6 |
| #define ETH_HLEN 14 |
| |
| #define ETH_P_IP 0x0800 /* Internet Protocol packet */ |
| #define ETH_P_ARP 0x0806 /* Address Resolution packet */ |
| |
| #define ARPOP_REQUEST 1 /* ARP request */ |
| #define ARPOP_REPLY 2 /* ARP reply */ |
| |
| struct ethhdr |
| { |
| unsigned char h_dest[ETH_ALEN]; /* destination eth addr */ |
| unsigned char h_source[ETH_ALEN]; /* source ether addr */ |
| unsigned short h_proto; /* packet type ID field */ |
| }; |
| |
| struct arphdr |
| { |
| unsigned short ar_hrd; /* format of hardware address */ |
| unsigned short ar_pro; /* format of protocol address */ |
| unsigned char ar_hln; /* length of hardware address */ |
| unsigned char ar_pln; /* length of protocol address */ |
| unsigned short ar_op; /* ARP opcode (command) */ |
| |
| /* |
| * Ethernet looks like this : This bit is variable sized however... |
| */ |
| unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */ |
| unsigned char ar_sip[4]; /* sender IP address */ |
| unsigned char ar_tha[ETH_ALEN]; /* target hardware address */ |
| unsigned char ar_tip[4]; /* target IP address */ |
| }; |
| |
| void arp_input(const uint8_t *pkt, int pkt_len) |
| { |
| struct ethhdr *eh = (struct ethhdr *)pkt; |
| struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN); |
| uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)]; |
| struct ethhdr *reh = (struct ethhdr *)arp_reply; |
| struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN); |
| int ar_op; |
| |
| ar_op = ntohs(ah->ar_op); |
| switch(ar_op) { |
| case ARPOP_REQUEST: |
| if (!memcmp(ah->ar_tip, &special_addr, 3) && |
| (ah->ar_tip[3] == CTL_DNS || ah->ar_tip[3] == CTL_ALIAS)) { |
| |
| /* XXX: make an ARP request to have the client address */ |
| memcpy(client_ethaddr, eh->h_source, ETH_ALEN); |
| |
| /* ARP request for alias/dns mac address */ |
| memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN); |
| memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1); |
| reh->h_source[5] = ah->ar_tip[3]; |
| reh->h_proto = htons(ETH_P_ARP); |
| |
| rah->ar_hrd = htons(1); |
| rah->ar_pro = htons(ETH_P_IP); |
| rah->ar_hln = ETH_ALEN; |
| rah->ar_pln = 4; |
| rah->ar_op = htons(ARPOP_REPLY); |
| memcpy(rah->ar_sha, reh->h_source, ETH_ALEN); |
| memcpy(rah->ar_sip, ah->ar_tip, 4); |
| memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN); |
| memcpy(rah->ar_tip, ah->ar_sip, 4); |
| slirp_output(arp_reply, sizeof(arp_reply)); |
| } |
| break; |
| default: |
| break; |
| } |
| } |
| |
| void slirp_input(const uint8_t *pkt, int pkt_len) |
| { |
| struct mbuf *m; |
| int proto; |
| |
| if (pkt_len < ETH_HLEN) |
| return; |
| |
| proto = ntohs(*(uint16_t *)(pkt + 12)); |
| switch(proto) { |
| case ETH_P_ARP: |
| arp_input(pkt, pkt_len); |
| break; |
| case ETH_P_IP: |
| m = m_get(); |
| if (!m) |
| return; |
| m->m_len = pkt_len; |
| memcpy(m->m_data, pkt, pkt_len); |
| |
| m->m_data += ETH_HLEN; |
| m->m_len -= ETH_HLEN; |
| |
| ip_input(m); |
| break; |
| default: |
| break; |
| } |
| } |
| |
| /* output the IP packet to the ethernet device */ |
| void if_encap(const uint8_t *ip_data, int ip_data_len) |
| { |
| uint8_t buf[1600]; |
| struct ethhdr *eh = (struct ethhdr *)buf; |
| |
| if (ip_data_len + ETH_HLEN > sizeof(buf)) |
| return; |
| |
| memcpy(eh->h_dest, client_ethaddr, ETH_ALEN); |
| memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 1); |
| eh->h_source[5] = CTL_ALIAS; |
| eh->h_proto = htons(ETH_P_IP); |
| memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len); |
| slirp_output(buf, ip_data_len + ETH_HLEN); |
| } |