diff options
Diffstat (limited to 'slirp/slirp.c')
| -rw-r--r-- | slirp/slirp.c | 550 |
1 files changed, 550 insertions, 0 deletions
diff --git a/slirp/slirp.c b/slirp/slirp.c new file mode 100644 index 0000000000..48b45a39cd --- /dev/null +++ b/slirp/slirp.c @@ -0,0 +1,550 @@ +#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); +} |