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-rw-r--r--slirp/slirp.c550
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);
+}
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