initial user mode network support

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@733 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 384 insertions, 0 deletions

diff --git a/ip_icmp.c b/ip_icmp.c
new file mode 100644
index 0000000..c8aaf4f
--- /dev/null
+++ b/ip_icmp.c
@@ -0,0 +1,384 @@
+/*
+ * Copyright (c) 1982, 1986, 1988, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ *	@(#)ip_icmp.c	8.2 (Berkeley) 1/4/94
+ * ip_icmp.c,v 1.7 1995/05/30 08:09:42 rgrimes Exp
+ */
+
+#include "slirp.h"
+#include "ip_icmp.h"
+
+struct icmpstat icmpstat;
+
+/* The message sent when emulating PING */
+/* Be nice and tell them it's just a psuedo-ping packet */
+char icmp_ping_msg[] = "This is a psuedo-PING packet used by Slirp to emulate "
+                       "ICMP ECHO-REQUEST packets.\n";
+
+/* list of actions for icmp_error() on RX of an icmp message */
+static int icmp_flush[19] = {
+    /*  ECHO REPLY (0)  */ 0,
+    1,
+    1,
+    /* DEST UNREACH (3) */ 1,
+    /* SOURCE QUENCH (4)*/ 1,
+    /* REDIRECT (5) */ 1,
+    1,
+    1,
+    /* ECHO (8) */ 0,
+    /* ROUTERADVERT (9) */ 1,
+    /* ROUTERSOLICIT (10) */ 1,
+    /* TIME EXCEEDED (11) */ 1,
+    /* PARAMETER PROBLEM (12) */ 1,
+    /* TIMESTAMP (13) */ 0,
+    /* TIMESTAMP REPLY (14) */ 0,
+    /* INFO (15) */ 0,
+    /* INFO REPLY (16) */ 0,
+    /* ADDR MASK (17) */ 0,
+    /* ADDR MASK REPLY (18) */ 0
+};
+
+/*
+ * Process a received ICMP message.
+ */
+void icmp_input(m, hlen) 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);
+
+    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 == our_addr.s_addr ||
+            (ip->ip_dst.s_addr == (special_addr.s_addr | htonl(CTL_ALIAS)))) {
+            icmp_reflect(m);
+        } else {
+            struct socket *so;
+            struct sockaddr_in addr;
+            if ((so = socreate()) == NULL)
+                goto freeit;
+            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 & 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((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 == our_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;
+}
+
+
+/*
+ *	Send an ICMP message in response to a situation
+ *
+ *	RFC 1122: 3.2.2	MUST send at least the IP header and 8 bytes of header.
+ *MAY send more (we do). MUST NOT change this header information. MUST NOT reply
+ *to a multicast/broadcast IP address. MUST NOT reply to a multicast/broadcast
+ *MAC address. MUST reply to only the first fragment.
+ */
+/*
+ * Send ICMP_UNREACH back to the source regarding msrc.
+ * mbuf *msrc is used as a template, but is NOT m_free()'d.
+ * It is reported as the bad ip packet.  The header should
+ * be fully correct and in host byte order.
+ * ICMP fragmentation is illegal.  All machines must accept 576 bytes in one
+ * packet.  The maximum payload is 576-20(ip hdr)-8(icmp hdr)=548
+ */
+
+#define ICMP_MAXDATALEN (IP_MSS - 28)
+void icmp_error(msrc, type, code, minsize, message) struct mbuf *msrc;
+u_char type;
+u_char code;
+int minsize;
+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 *);
+#if 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 */
+
+    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 */
+    if (!(m = m_get()))
+        goto end_error; /* get mbuf */
+    {
+        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);
+
+#if 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 = our_addr;
+
+    (void)ip_output((struct socket *)NULL, m);
+
+    icmpstat.icps_reflect++;
+
+end_error:
+    return;
+}
+#undef ICMP_MAXDATALEN
+
+/*
+ * Reflect the ip packet back to the source
+ */
+void icmp_reflect(m) struct mbuf *m;
+{
+    register struct ip *ip = mtod(m, struct ip *);
+    int hlen = ip->ip_hl << 2;
+    int optlen = hlen - sizeof(struct ip);
+    register struct icmp *icp;
+
+    /*
+     * Send an icmp packet back to the ip level,
+     * after supplying a checksum.
+     */
+    m->m_data += hlen;
+    m->m_len -= hlen;
+    icp = mtod(m, struct icmp *);
+
+    icp->icmp_cksum = 0;
+    icp->icmp_cksum = cksum(m, ip->ip_len - hlen);
+
+    m->m_data -= hlen;
+    m->m_len += hlen;
+
+    /* fill in ip */
+    if (optlen > 0) {
+        /*
+         * Strip out original options by copying rest of first
+         * mbuf's data back, and adjust the IP length.
+         */
+        memmove((caddr_t)(ip + 1), (caddr_t)ip + hlen,
+                (unsigned)(m->m_len - hlen));
+        hlen -= optlen;
+        ip->ip_hl = hlen >> 2;
+        ip->ip_len -= optlen;
+        m->m_len -= optlen;
+    }
+
+    ip->ip_ttl = MAXTTL;
+    { /* swap */
+        struct in_addr icmp_dst;
+        icmp_dst = ip->ip_dst;
+        ip->ip_dst = ip->ip_src;
+        ip->ip_src = icmp_dst;
+    }
+
+    (void)ip_output((struct socket *)NULL, m);
+
+    icmpstat.icps_reflect++;
+}