src/slirp/slirp.c

#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;
struct ex_list *exec_list;

/* 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)
{
    FIXED_INFO *FixedInfo=NULL;
    ULONG    BufLen;
    DWORD    ret;
    IP_ADDR_STRING *pIPAddr;
    struct in_addr tmp_addr;
    
    FixedInfo = (FIXED_INFO *)GlobalAlloc(GPTR, sizeof(FIXED_INFO));
    BufLen = sizeof(FIXED_INFO);
   
    if (ERROR_BUFFER_OVERFLOW == GetNetworkParams(FixedInfo, &BufLen)) {
        if (FixedInfo) {
            GlobalFree(FixedInfo);
            FixedInfo = NULL;
        }
        FixedInfo = GlobalAlloc(GPTR, BufLen);
    }
        
    if ((ret = GetNetworkParams(FixedInfo, &BufLen)) != ERROR_SUCCESS) {
        printf("GetNetworkParams failed. ret = %08x\n", (u_int)ret );
        if (FixedInfo) {
            GlobalFree(FixedInfo);
            FixedInfo = NULL;
        }
        return -1;
    }
     
    pIPAddr = &(FixedInfo->DnsServerList);
    inet_aton(pIPAddr->IpAddress.String, &tmp_addr);
    *pdns_addr = tmp_addr;
#if 0
    printf( "DNS Servers:\n" );
    printf( "DNS Addr:%s\n", pIPAddr->IpAddress.String );
    
    pIPAddr = FixedInfo -> DnsServerList.Next;
    while ( pIPAddr ) {
            printf( "DNS Addr:%s\n", pIPAddr ->IpAddress.String );
            pIPAddr = pIPAddr ->Next;
    }
#endif
    if (FixedInfo) {
        GlobalFree(FixedInfo);
        FixedInfo = NULL;
    }
    return 0;
}

#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));
        }
    }
    fclose(f);
    if (!found)
        return -1;
    return 0;
}

#endif

#ifdef _WIN32
void slirp_cleanup(void)
{
    WSACleanup();
}
#endif

int slirp_init(void)
{
    //    debug_init("/tmp/slirp.log", DEBUG_DEFAULT);
    
#ifdef _WIN32
    {
        WSADATA Data;
        WSAStartup(MAKEWORD(2,0), &Data);
        atexit(slirp_cleanup);
    }
#endif

    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)
        return -1;

    inet_aton(CTL_SPECIAL, &special_addr);
    return 0;
}

#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
 */
#ifdef _WIN32
static void updtime(void)
{
    struct _timeb tb;

    _ftime(&tb);
    curtime = (u_int)tb.time * (u_int)1000;
    curtime += (u_int)tb.millitm;
}
#else
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++;
}
#endif

int slirp_select_fill(int *pnfds, 
                                          fd_set *readfds, fd_set *writefds, fd_set *xfds)
{
    struct socket *so, *so_next;
    int nfds;
    int timeout, 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
         */

        timeout = -1;

        /*
         * If a slowtimo is needed, set timeout to 5ms from the last
         * slow timeout. If a fast timeout is needed, set timeout within
         * 2ms of when it was requested.
         */
#       define SLOW_TIMO 5
#       define FAST_TIMO 2
        if (do_slowtimo) {
                timeout = (SLOW_TIMO - (curtime - last_slowtimo)) * 1000;
                if (timeout < 0)
                   timeout = 0;
                else if (timeout > (SLOW_TIMO * 1000))
                   timeout = SLOW_TIMO * 1000;
                
                /* Can only fasttimo if we also slowtimo */
                if (time_fasttimo) {
                        tmp_time = (FAST_TIMO - (curtime - time_fasttimo)) * 1000;
                        if (tmp_time < 0)
                                tmp_time = 0;
                        
                        /* Choose the smallest of the 2 */
                        if (tmp_time < timeout)
                           timeout = tmp_time;
                }
        }
        *pnfds = nfds;

        /*
         * Adjust the timeout to make the minimum timeout
         * 2ms (XXX?) to lessen the CPU load
         */
        if (timeout < (FAST_TIMO * 1000))
                timeout = FAST_TIMO * 1000;

        return timeout;
}       

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) >= FAST_TIMO)) {
                        tcp_fasttimo();
                        time_fasttimo = 0;
                }
                if (do_slowtimo && ((curtime - last_slowtimo) >= SLOW_TIMO)) {
                        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 = send(so->s, &ret, 0, 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 = recv(so->s, (char *)&ret, 0,0);
                          
                          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 = send(so->s, &ret, 0,0);
                            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();

        /* clear global file descriptor sets.
         * these reside on the stack in vl.c
         * so they're unusable if we're not in
         * slirp_select_fill or slirp_select_poll.
         */
         global_readfds = NULL;
         global_writefds = NULL;
         global_xfds = NULL;
}

#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;
    struct ex_list *ex_ptr;

    ar_op = ntohs(ah->ar_op);
    switch(ar_op) {
    case ARPOP_REQUEST:
        if (!memcmp(ah->ar_tip, &special_addr, 3)) {
            if (ah->ar_tip[3] == CTL_DNS || ah->ar_tip[3] == CTL_ALIAS) 
                goto arp_ok;
            for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
                if (ex_ptr->ex_addr == ah->ar_tip[3])
                    goto arp_ok;
            }
            return;
        arp_ok:
            /* 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 = (pkt[12] << 8) | pkt[13];
    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);
    /* XXX: not correct */
    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);
}

int slirp_redir(int is_udp, int host_port, 
                struct in_addr guest_addr, int guest_port)
{
    if (is_udp) {
        if (!udp_listen(htons(host_port), guest_addr.s_addr, 
                        htons(guest_port), 0))
            return -1;
    } else {
        if (!solisten(htons(host_port), guest_addr.s_addr, 
                      htons(guest_port), 0))
            return -1;
    }
    return 0;
}

int slirp_add_exec(int do_pty, const char *args, int addr_low_byte, 
                  int guest_port)
{
    return add_exec(&exec_list, do_pty, (char *)args, 
                    addr_low_byte, htons(guest_port));
}
Revision:	1.6
Committed:	2006-04-26T06:26:14Z (18 years, 1 month ago) by gbeauche
Content type:	text/plain
Branch:	MAIN
Changes since 1.5:	+2 -2 lines
Log Message:	FAST_TIMO is 2 ms not 2 usec. Noticed on Windows but this obviously can't fix my problem with slirp_select_fill() there as it still doesn't fill in any socket descriptor. :-/ I think I won't bother much for Windows...
#	User	Rev	Content
1	gbeauche	1.1	#include "slirp.h"
2
3			/* host address */
4			struct in_addr our_addr;
5			/* host dns address */
6			struct in_addr dns_addr;
7			/* host loopback address */
8			struct in_addr loopback_addr;
9
10			/* address for slirp virtual addresses */
11			struct in_addr special_addr;
12
13			const uint8_t special_ethaddr[6] = {
14			0x52, 0x54, 0x00, 0x12, 0x35, 0x00
15			};
16
17			uint8_t client_ethaddr[6];
18
19			int do_slowtimo;
20			int link_up;
21			struct timeval tt;
22			FILE *lfd;
23			struct ex_list *exec_list;
24
25			/* XXX: suppress those select globals */
26			fd_set global_readfds, global_writefds, *global_xfds;
27
28			#ifdef _WIN32
29
30			static int get_dns_addr(struct in_addr *pdns_addr)
31			{
32			FIXED_INFO *FixedInfo=NULL;
33			ULONG BufLen;
34			DWORD ret;
35			IP_ADDR_STRING *pIPAddr;
36			struct in_addr tmp_addr;
37
38			FixedInfo = (FIXED_INFO *)GlobalAlloc(GPTR, sizeof(FIXED_INFO));
39			BufLen = sizeof(FIXED_INFO);
40
41			if (ERROR_BUFFER_OVERFLOW == GetNetworkParams(FixedInfo, &BufLen)) {
42			if (FixedInfo) {
43			GlobalFree(FixedInfo);
44			FixedInfo = NULL;
45			}
46			FixedInfo = GlobalAlloc(GPTR, BufLen);
47			}
48
49			if ((ret = GetNetworkParams(FixedInfo, &BufLen)) != ERROR_SUCCESS) {
50			printf("GetNetworkParams failed. ret = %08x\n", (u_int)ret );
51			if (FixedInfo) {
52			GlobalFree(FixedInfo);
53			FixedInfo = NULL;
54			}
55			return -1;
56			}
57
58			pIPAddr = &(FixedInfo->DnsServerList);
59			inet_aton(pIPAddr->IpAddress.String, &tmp_addr);
60			*pdns_addr = tmp_addr;
61			#if 0
62			printf( "DNS Servers:\n" );
63			printf( "DNS Addr:%s\n", pIPAddr->IpAddress.String );
64
65			pIPAddr = FixedInfo -> DnsServerList.Next;
66			while ( pIPAddr ) {
67			printf( "DNS Addr:%s\n", pIPAddr ->IpAddress.String );
68			pIPAddr = pIPAddr ->Next;
69			}
70			#endif
71			if (FixedInfo) {
72			GlobalFree(FixedInfo);
73			FixedInfo = NULL;
74			}
75			return 0;
76			}
77
78			#else
79
80			static int get_dns_addr(struct in_addr *pdns_addr)
81			{
82			char buff[512];
83			char buff2[256];
84			FILE *f;
85			int found = 0;
86			struct in_addr tmp_addr;
87
88			f = fopen("/etc/resolv.conf", "r");
89			if (!f)
90			return -1;
91
92			lprint("IP address of your DNS(s): ");
93			while (fgets(buff, 512, f) != NULL) {
94			if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) {
95			if (!inet_aton(buff2, &tmp_addr))
96			continue;
97			if (tmp_addr.s_addr == loopback_addr.s_addr)
98			tmp_addr = our_addr;
99			/* If it's the first one, set it to dns_addr */
100			if (!found)
101			*pdns_addr = tmp_addr;
102			else
103			lprint(", ");
104			if (++found > 3) {
105			lprint("(more)");
106			break;
107			} else
108			lprint("%s", inet_ntoa(tmp_addr));
109			}
110			}
111			fclose(f);
112			if (!found)
113			return -1;
114			return 0;
115			}
116
117			#endif
118
119			#ifdef _WIN32
120			void slirp_cleanup(void)
121			{
122			WSACleanup();
123			}
124			#endif
125
126	gbeauche	1.2	int slirp_init(void)
127	gbeauche	1.1	{
128			// debug_init("/tmp/slirp.log", DEBUG_DEFAULT);
129
130			#ifdef _WIN32
131			{
132			WSADATA Data;
133			WSAStartup(MAKEWORD(2,0), &Data);
134			atexit(slirp_cleanup);
135			}
136			#endif
137
138			link_up = 1;
139
140			if_init();
141			ip_init();
142
143			/* Initialise mbufs after setting the MTU */
144			m_init();
145
146			/* set default addresses */
147			getouraddr();
148			inet_aton("127.0.0.1", &loopback_addr);
149
150	gbeauche	1.2	if (get_dns_addr(&dns_addr) < 0)
151			return -1;
152	gbeauche	1.1
153			inet_aton(CTL_SPECIAL, &special_addr);
154	gbeauche	1.2	return 0;
155	gbeauche	1.1	}
156
157			#define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE\|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
158			#define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE\|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
159			#define UPD_NFDS(x) if (nfds < (x)) nfds = (x)
160
161			/*
162			* curtime kept to an accuracy of 1ms
163			*/
164			#ifdef _WIN32
165			static void updtime(void)
166			{
167			struct _timeb tb;
168
169			_ftime(&tb);
170			curtime = (u_int)tb.time * (u_int)1000;
171			curtime += (u_int)tb.millitm;
172			}
173			#else
174			static void updtime(void)
175			{
176			gettimeofday(&tt, 0);
177
178			curtime = (u_int)tt.tv_sec * (u_int)1000;
179			curtime += (u_int)tt.tv_usec / (u_int)1000;
180
181			if ((tt.tv_usec % 1000) >= 500)
182			curtime++;
183			}
184			#endif
185
186	gbeauche	1.5	int slirp_select_fill(int *pnfds,
187			fd_set readfds, fd_set writefds, fd_set *xfds)
188	gbeauche	1.1	{
189			struct socket so, so_next;
190			int nfds;
191	gbeauche	1.5	int timeout, tmp_time;
192	gbeauche	1.1
193			/* fail safe */
194			global_readfds = NULL;
195			global_writefds = NULL;
196			global_xfds = NULL;
197
198			nfds = *pnfds;
199			/*
200			* First, TCP sockets
201			*/
202			do_slowtimo = 0;
203			if (link_up) {
204			/*
205			* *_slowtimo needs calling if there are IP fragments
206			* in the fragment queue, or there are TCP connections active
207			*/
208			do_slowtimo = ((tcb.so_next != &tcb) \|\|
209			((struct ipasfrag )&ipq != (struct ipasfrag )ipq.next));
210
211			for (so = tcb.so_next; so != &tcb; so = so_next) {
212			so_next = so->so_next;
213
214			/*
215			* See if we need a tcp_fasttimo
216			*/
217			if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK)
218			time_fasttimo = curtime; /* Flag when we want a fasttimo */
219
220			/*
221			* NOFDREF can include still connecting to local-host,
222			* newly socreated() sockets etc. Don't want to select these.
223			*/
224			if (so->so_state & SS_NOFDREF \|\| so->s == -1)
225			continue;
226
227			/*
228			* Set for reading sockets which are accepting
229			*/
230			if (so->so_state & SS_FACCEPTCONN) {
231			FD_SET(so->s, readfds);
232			UPD_NFDS(so->s);
233			continue;
234			}
235
236			/*
237			* Set for writing sockets which are connecting
238			*/
239			if (so->so_state & SS_ISFCONNECTING) {
240			FD_SET(so->s, writefds);
241			UPD_NFDS(so->s);
242			continue;
243			}
244
245			/*
246			* Set for writing if we are connected, can send more, and
247			* we have something to send
248			*/
249			if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) {
250			FD_SET(so->s, writefds);
251			UPD_NFDS(so->s);
252			}
253
254			/*
255			* Set for reading (and urgent data) if we are connected, can
256			* receive more, and we have room for it XXX /2 ?
257			*/
258			if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) {
259			FD_SET(so->s, readfds);
260			FD_SET(so->s, xfds);
261			UPD_NFDS(so->s);
262			}
263			}
264
265			/*
266			* UDP sockets
267			*/
268			for (so = udb.so_next; so != &udb; so = so_next) {
269			so_next = so->so_next;
270
271			/*
272			* See if it's timed out
273			*/
274			if (so->so_expire) {
275			if (so->so_expire <= curtime) {
276			udp_detach(so);
277			continue;
278			} else
279			do_slowtimo = 1; /* Let socket expire */
280			}
281
282			/*
283			* When UDP packets are received from over the
284			* link, they're sendto()'d straight away, so
285			* no need for setting for writing
286			* Limit the number of packets queued by this session
287			* to 4. Note that even though we try and limit this
288			* to 4 packets, the session could have more queued
289			* if the packets needed to be fragmented
290			* (XXX <= 4 ?)
291			*/
292			if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) {
293			FD_SET(so->s, readfds);
294			UPD_NFDS(so->s);
295			}
296			}
297			}
298
299			/*
300			* Setup timeout to use minimum CPU usage, especially when idle
301			*/
302	gbeauche	1.5
303			timeout = -1;
304
305	gbeauche	1.1	/*
306	gbeauche	1.5	* If a slowtimo is needed, set timeout to 5ms from the last
307	gbeauche	1.1	* slow timeout. If a fast timeout is needed, set timeout within
308	gbeauche	1.5	* 2ms of when it was requested.
309	gbeauche	1.1	*/
310	gbeauche	1.5	# define SLOW_TIMO 5
311			# define FAST_TIMO 2
312	gbeauche	1.1	if (do_slowtimo) {
313	gbeauche	1.5	timeout = (SLOW_TIMO - (curtime - last_slowtimo)) * 1000;
314			if (timeout < 0)
315			timeout = 0;
316			else if (timeout > (SLOW_TIMO * 1000))
317			timeout = SLOW_TIMO * 1000;
318	gbeauche	1.1
319			/* Can only fasttimo if we also slowtimo */
320			if (time_fasttimo) {
321	gbeauche	1.5	tmp_time = (FAST_TIMO - (curtime - time_fasttimo)) * 1000;
322	gbeauche	1.1	if (tmp_time < 0)
323	gbeauche	1.5	tmp_time = 0;
324	gbeauche	1.1
325			/* Choose the smallest of the 2 */
326	gbeauche	1.5	if (tmp_time < timeout)
327			timeout = tmp_time;
328	gbeauche	1.1	}
329			}
330	gbeauche	1.5	*pnfds = nfds;
331
332			/*
333			* Adjust the timeout to make the minimum timeout
334			* 2ms (XXX?) to lessen the CPU load
335			*/
336	gbeauche	1.6	if (timeout < (FAST_TIMO * 1000))
337			timeout = FAST_TIMO * 1000;
338	gbeauche	1.5
339			return timeout;
340	gbeauche	1.1	}
341
342			void slirp_select_poll(fd_set readfds, fd_set writefds, fd_set *xfds)
343			{
344			struct socket so, so_next;
345			int ret;
346
347			global_readfds = readfds;
348			global_writefds = writefds;
349			global_xfds = xfds;
350
351			/* Update time */
352			updtime();
353
354			/*
355			* See if anything has timed out
356			*/
357			if (link_up) {
358	gbeauche	1.5	if (time_fasttimo && ((curtime - time_fasttimo) >= FAST_TIMO)) {
359	gbeauche	1.1	tcp_fasttimo();
360			time_fasttimo = 0;
361			}
362	gbeauche	1.5	if (do_slowtimo && ((curtime - last_slowtimo) >= SLOW_TIMO)) {
363	gbeauche	1.1	ip_slowtimo();
364			tcp_slowtimo();
365			last_slowtimo = curtime;
366			}
367			}
368
369			/*
370			* Check sockets
371			*/
372			if (link_up) {
373			/*
374			* Check TCP sockets
375			*/
376			for (so = tcb.so_next; so != &tcb; so = so_next) {
377			so_next = so->so_next;
378
379			/*
380			* FD_ISSET is meaningless on these sockets
381			* (and they can crash the program)
382			*/
383			if (so->so_state & SS_NOFDREF \|\| so->s == -1)
384			continue;
385
386			/*
387			* Check for URG data
388			* This will soread as well, so no need to
389			* test for readfds below if this succeeds
390			*/
391			if (FD_ISSET(so->s, xfds))
392			sorecvoob(so);
393			/*
394			* Check sockets for reading
395			*/
396			else if (FD_ISSET(so->s, readfds)) {
397			/*
398			* Check for incoming connections
399			*/
400			if (so->so_state & SS_FACCEPTCONN) {
401			tcp_connect(so);
402			continue;
403			} /* else */
404			ret = soread(so);
405
406			/* Output it if we read something */
407			if (ret > 0)
408			tcp_output(sototcpcb(so));
409			}
410
411			/*
412			* Check sockets for writing
413			*/
414			if (FD_ISSET(so->s, writefds)) {
415			/*
416			* Check for non-blocking, still-connecting sockets
417			*/
418			if (so->so_state & SS_ISFCONNECTING) {
419			/* Connected */
420			so->so_state &= ~SS_ISFCONNECTING;
421
422			ret = send(so->s, &ret, 0, 0);
423			if (ret < 0) {
424			/* XXXXX Must fix, zero bytes is a NOP */
425			if (errno == EAGAIN \|\| errno == EWOULDBLOCK \|\|
426			errno == EINPROGRESS \|\| errno == ENOTCONN)
427			continue;
428
429			/* else failed */
430			so->so_state = SS_NOFDREF;
431			}
432			/* else so->so_state &= ~SS_ISFCONNECTING; */
433
434			/*
435			* Continue tcp_input
436			*/
437			tcp_input((struct mbuf *)NULL, sizeof(struct ip), so);
438			/* continue; */
439			} else
440			ret = sowrite(so);
441			/*
442			* XXXXX If we wrote something (a lot), there
443			* could be a need for a window update.
444			* In the worst case, the remote will send
445			* a window probe to get things going again
446			*/
447			}
448
449			/*
450			* Probe a still-connecting, non-blocking socket
451			* to check if it's still alive
452			*/
453			#ifdef PROBE_CONN
454			if (so->so_state & SS_ISFCONNECTING) {
455			ret = recv(so->s, (char *)&ret, 0,0);
456
457			if (ret < 0) {
458			/* XXX */
459			if (errno == EAGAIN \|\| errno == EWOULDBLOCK \|\|
460			errno == EINPROGRESS \|\| errno == ENOTCONN)
461			continue; /* Still connecting, continue */
462
463			/* else failed */
464			so->so_state = SS_NOFDREF;
465
466			/* tcp_input will take care of it */
467			} else {
468			ret = send(so->s, &ret, 0,0);
469			if (ret < 0) {
470			/* XXX */
471			if (errno == EAGAIN \|\| errno == EWOULDBLOCK \|\|
472			errno == EINPROGRESS \|\| errno == ENOTCONN)
473			continue;
474			/* else failed */
475			so->so_state = SS_NOFDREF;
476			} else
477			so->so_state &= ~SS_ISFCONNECTING;
478
479			}
480			tcp_input((struct mbuf *)NULL, sizeof(struct ip),so);
481			} /* SS_ISFCONNECTING */
482			#endif
483			}
484
485			/*
486			* Now UDP sockets.
487			* Incoming packets are sent straight away, they're not buffered.
488			* Incoming UDP data isn't buffered either.
489			*/
490			for (so = udb.so_next; so != &udb; so = so_next) {
491			so_next = so->so_next;
492
493			if (so->s != -1 && FD_ISSET(so->s, readfds)) {
494			sorecvfrom(so);
495			}
496			}
497			}
498
499			/*
500			* See if we can start outputting
501			*/
502			if (if_queued && link_up)
503			if_start();
504
505			/* clear global file descriptor sets.
506			* these reside on the stack in vl.c
507			* so they're unusable if we're not in
508			* slirp_select_fill or slirp_select_poll.
509			*/
510			global_readfds = NULL;
511			global_writefds = NULL;
512			global_xfds = NULL;
513			}
514
515			#define ETH_ALEN 6
516			#define ETH_HLEN 14
517
518			#define ETH_P_IP 0x0800 /* Internet Protocol packet */
519			#define ETH_P_ARP 0x0806 /* Address Resolution packet */
520
521			#define ARPOP_REQUEST 1 /* ARP request */
522			#define ARPOP_REPLY 2 /* ARP reply */
523
524			struct ethhdr
525			{
526			unsigned char h_dest[ETH_ALEN]; /* destination eth addr */
527			unsigned char h_source[ETH_ALEN]; /* source ether addr */
528			unsigned short h_proto; /* packet type ID field */
529			};
530
531			struct arphdr
532			{
533			unsigned short ar_hrd; /* format of hardware address */
534			unsigned short ar_pro; /* format of protocol address */
535			unsigned char ar_hln; /* length of hardware address */
536			unsigned char ar_pln; /* length of protocol address */
537			unsigned short ar_op; /* ARP opcode (command) */
538
539			/*
540			* Ethernet looks like this : This bit is variable sized however...
541			*/
542			unsigned char ar_sha[ETH_ALEN]; /* sender hardware address */
543			unsigned char ar_sip[4]; /* sender IP address */
544			unsigned char ar_tha[ETH_ALEN]; /* target hardware address */
545			unsigned char ar_tip[4]; /* target IP address */
546			};
547
548			void arp_input(const uint8_t *pkt, int pkt_len)
549			{
550			struct ethhdr eh = (struct ethhdr )pkt;
551			struct arphdr ah = (struct arphdr )(pkt + ETH_HLEN);
552			uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)];
553			struct ethhdr reh = (struct ethhdr )arp_reply;
554			struct arphdr rah = (struct arphdr )(arp_reply + ETH_HLEN);
555			int ar_op;
556			struct ex_list *ex_ptr;
557
558			ar_op = ntohs(ah->ar_op);
559			switch(ar_op) {
560			case ARPOP_REQUEST:
561			if (!memcmp(ah->ar_tip, &special_addr, 3)) {
562			if (ah->ar_tip[3] == CTL_DNS \|\| ah->ar_tip[3] == CTL_ALIAS)
563			goto arp_ok;
564			for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
565			if (ex_ptr->ex_addr == ah->ar_tip[3])
566			goto arp_ok;
567			}
568			return;
569			arp_ok:
570			/* XXX: make an ARP request to have the client address */
571			memcpy(client_ethaddr, eh->h_source, ETH_ALEN);
572
573			/* ARP request for alias/dns mac address */
574			memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
575			memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1);
576			reh->h_source[5] = ah->ar_tip[3];
577			reh->h_proto = htons(ETH_P_ARP);
578
579			rah->ar_hrd = htons(1);
580			rah->ar_pro = htons(ETH_P_IP);
581			rah->ar_hln = ETH_ALEN;
582			rah->ar_pln = 4;
583			rah->ar_op = htons(ARPOP_REPLY);
584			memcpy(rah->ar_sha, reh->h_source, ETH_ALEN);
585			memcpy(rah->ar_sip, ah->ar_tip, 4);
586			memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN);
587			memcpy(rah->ar_tip, ah->ar_sip, 4);
588			slirp_output(arp_reply, sizeof(arp_reply));
589			}
590			break;
591			default:
592			break;
593			}
594			}
595
596			void slirp_input(const uint8_t *pkt, int pkt_len)
597			{
598			struct mbuf *m;
599			int proto;
600
601			if (pkt_len < ETH_HLEN)
602			return;
603
604	gbeauche	1.3	proto = (pkt[12] << 8) \| pkt[13];
605	gbeauche	1.1	switch(proto) {
606			case ETH_P_ARP:
607			arp_input(pkt, pkt_len);
608			break;
609			case ETH_P_IP:
610			m = m_get();
611			if (!m)
612			return;
613			m->m_len = pkt_len;
614			memcpy(m->m_data, pkt, pkt_len);
615
616			m->m_data += ETH_HLEN;
617			m->m_len -= ETH_HLEN;
618
619			ip_input(m);
620			break;
621			default:
622			break;
623			}
624			}
625
626			/* output the IP packet to the ethernet device */
627			void if_encap(const uint8_t *ip_data, int ip_data_len)
628			{
629			uint8_t buf[1600];
630			struct ethhdr eh = (struct ethhdr )buf;
631
632			if (ip_data_len + ETH_HLEN > sizeof(buf))
633			return;
634
635			memcpy(eh->h_dest, client_ethaddr, ETH_ALEN);
636			memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 1);
637			/* XXX: not correct */
638			eh->h_source[5] = CTL_ALIAS;
639			eh->h_proto = htons(ETH_P_IP);
640			memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len);
641			slirp_output(buf, ip_data_len + ETH_HLEN);
642			}
643
644			int slirp_redir(int is_udp, int host_port,
645			struct in_addr guest_addr, int guest_port)
646			{
647			if (is_udp) {
648			if (!udp_listen(htons(host_port), guest_addr.s_addr,
649			htons(guest_port), 0))
650			return -1;
651			} else {
652			if (!solisten(htons(host_port), guest_addr.s_addr,
653			htons(guest_port), 0))
654			return -1;
655			}
656			return 0;
657			}
658
659			int slirp_add_exec(int do_pty, const char *args, int addr_low_byte,
660			int guest_port)
661			{
662			return add_exec(&exec_list, do_pty, (char *)args,
663			addr_low_byte, htons(guest_port));
664			}