check for null mbuf ptr before freeing (4.3BSD/sys/{130,131,133})

[unix-history] / usr / src / sys / netinet / ip_output.c

diff --git a/usr/src/sys/netinet/ip_output.c b/usr/src/sys/netinet/ip_output.c
index dd508ce..0e18353 100644 (file)
--- a/usr/src/sys/netinet/ip_output.c
+++ b/usr/src/sys/netinet/ip_output.c
@@ -1,46 +1,65 @@
-/*     ip_output.c     6.2     83/10/22        */
+/*
+ * Copyright (c) 1982, 1986 Regents of the University of California.
+ * All rights reserved.  The Berkeley software License Agreement
+ * specifies the terms and conditions for redistribution.
+ *
+ *     @(#)ip_output.c 7.6 (Berkeley) %G%
+ */

 
 

-#include "../h/param.h"
-#include "../h/mbuf.h"
-#include "../h/errno.h"
-#include "../h/socket.h"
-#include "../h/socketvar.h"
+#include "param.h"
+#include "mbuf.h"
+#include "errno.h"
+#include "protosw.h"
+#include "socket.h"
+#include "socketvar.h"

 
 #include "../net/if.h"
 #include "../net/route.h"
 
 
 #include "../net/if.h"
 #include "../net/route.h"
 

-#include "../netinet/in.h"
-#include "../netinet/in_systm.h"
-#include "../netinet/ip.h"
-#include "../netinet/ip_var.h"
+#include "in.h"
+#include "in_pcb.h"
+#include "in_systm.h"
+#include "in_var.h"
+#include "ip.h"
+#include "ip_var.h"

 
 #ifdef vax
 
 #ifdef vax

-#include "../vax/mtpr.h"
+#include "../machine/mtpr.h"

 #endif
 
 #endif
 

+struct mbuf *ip_insertoptions();
+
+/*
+ * IP output.  The packet in mbuf chain m contains a skeletal IP
+ * header (with len, off, ttl, proto, tos, src, dst).
+ * The mbuf chain containing the packet will be freed.
+ * The mbuf opt, if present, will not be freed.
+ */

 ip_output(m, opt, ro, flags)
        struct mbuf *m;
        struct mbuf *opt;
        struct route *ro;
        int flags;
 {
 ip_output(m, opt, ro, flags)
        struct mbuf *m;
        struct mbuf *opt;
        struct route *ro;
        int flags;
 {

-       register struct ip *ip = mtod(m, struct ip *);
+       register struct ip *ip;

        register struct ifnet *ifp;
        int len, hlen = sizeof (struct ip), off, error = 0;
        struct route iproute;
        register struct ifnet *ifp;
        int len, hlen = sizeof (struct ip), off, error = 0;
        struct route iproute;

-       struct sockaddr *dst;
+       struct sockaddr_in *dst;

 
 

-       if (opt)                                /* XXX */
-               (void) m_free(opt);             /* XXX */
+       if (opt)
+               m = ip_insertoptions(m, opt, &hlen);
+       ip = mtod(m, struct ip *);

        /*
         * Fill in IP header.
         */
        /*
         * Fill in IP header.
         */

-       ip->ip_hl = hlen >> 2;

        if ((flags & IP_FORWARDING) == 0) {
                ip->ip_v = IPVERSION;
                ip->ip_off &= IP_DF;
                ip->ip_id = htons(ip_id++);
        if ((flags & IP_FORWARDING) == 0) {
                ip->ip_v = IPVERSION;
                ip->ip_off &= IP_DF;
                ip->ip_id = htons(ip_id++);

-       }
+               ip->ip_hl = hlen >> 2;
+       } else
+               hlen = ip->ip_hl << 2;

 
        /*
         * Route packet.
 
        /*
         * Route packet.


@@ -49,48 +68,71 @@ ip_output(m, opt, ro, flags)
                ro = &iproute;
                bzero((caddr_t)ro, sizeof (*ro));
        }
                ro = &iproute;
                bzero((caddr_t)ro, sizeof (*ro));
        }

-       dst = &ro->ro_dst;
+       dst = (struct sockaddr_in *)&ro->ro_dst;
+       /*
+        * If there is a cached route,
+        * check that it is to the same destination
+        * and is still up.  If not, free it and try again.
+        */
+       if (ro->ro_rt && ((ro->ro_rt->rt_flags & RTF_UP) == 0 ||
+          dst->sin_addr.s_addr != ip->ip_dst.s_addr)) {
+               RTFREE(ro->ro_rt);
+               ro->ro_rt = (struct rtentry *)0;
+       }

        if (ro->ro_rt == 0) {
        if (ro->ro_rt == 0) {

-               ro->ro_dst.sa_family = AF_INET;
-               ((struct sockaddr_in *)&ro->ro_dst)->sin_addr = ip->ip_dst;
-               /*
-                * If routing to interface only,
-                * short circuit routing lookup.
-                */
-               if (flags & IP_ROUTETOIF) {
-                       ifp = if_ifonnetof(in_netof(ip->ip_dst));
-                       if (ifp == 0) {
+               dst->sin_family = AF_INET;
+               dst->sin_addr = ip->ip_dst;
+       }
+       /*
+        * If routing to interface only,
+        * short circuit routing lookup.
+        */
+       if (flags & IP_ROUTETOIF) {
+               struct in_ifaddr *ia;
+
+               ia = (struct in_ifaddr *)ifa_ifwithdstaddr(dst);
+               if (ia == 0)
+                       ia = in_iaonnetof(in_netof(ip->ip_dst));
+               if (ia == 0) {
+                       error = ENETUNREACH;
+                       goto bad;
+               }
+               ifp = ia->ia_ifp;
+       } else {
+               if (ro->ro_rt == 0)
+                       rtalloc(ro);
+               if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) {
+                       if (in_localaddr(ip->ip_dst))
+                               error = EHOSTUNREACH;
+                       else

                                error = ENETUNREACH;
                                error = ENETUNREACH;

-                               goto bad;
-                       }
-                       goto gotif;
+                       goto bad;

                }
                }

-               rtalloc(ro);
-       }
-       if (ro->ro_rt == 0 || (ifp = ro->ro_rt->rt_ifp) == 0) {
-               error = ENETUNREACH;
-               goto bad;
+               ro->ro_rt->rt_use++;
+               if (ro->ro_rt->rt_flags & RTF_GATEWAY)
+                       dst = (struct sockaddr_in *)&ro->ro_rt->rt_gateway;

        }
        }

-       ro->ro_rt->rt_use++;
-       if (ro->ro_rt->rt_flags & (RTF_GATEWAY|RTF_HOST))
-               dst = &ro->ro_rt->rt_gateway;
-gotif:

 #ifndef notdef
        /*
         * If source address not specified yet, use address
         * of outgoing interface.
         */
 #ifndef notdef
        /*
         * If source address not specified yet, use address
         * of outgoing interface.
         */

-       if (in_lnaof(ip->ip_src) == INADDR_ANY)
-               ip->ip_src.s_addr =
-                   ((struct sockaddr_in *)&ifp->if_addr)->sin_addr.s_addr;
-#endif
+       if (ip->ip_src.s_addr == INADDR_ANY) {
+               register struct in_ifaddr *ia;

 
 

+               for (ia = in_ifaddr; ia; ia = ia->ia_next)
+                       if (ia->ia_ifp == ifp) {
+                               ip->ip_src = IA_SIN(ia)->sin_addr;
+                               break;
+                       }
+       }
+#endif

        /*
         * Look for broadcast address and
         * and verify user is allowed to send
         * such a packet.
         */
        /*
         * Look for broadcast address and
         * and verify user is allowed to send
         * such a packet.
         */

-       if (in_lnaof(((struct sockaddr_in *)dst)->sin_addr) == INADDR_ANY) {
+       if (in_broadcast(dst->sin_addr)) {

                if ((ifp->if_flags & IFF_BROADCAST) == 0) {
                        error = EADDRNOTAVAIL;
                        goto bad;
                if ((ifp->if_flags & IFF_BROADCAST) == 0) {
                        error = EADDRNOTAVAIL;
                        goto bad;


@@ -114,7 +156,7 @@ gotif:
                ip->ip_off = htons((u_short)ip->ip_off);
                ip->ip_sum = 0;
                ip->ip_sum = in_cksum(m, hlen);
                ip->ip_off = htons((u_short)ip->ip_off);
                ip->ip_sum = 0;
                ip->ip_sum = in_cksum(m, hlen);

-               error = (*ifp->if_output)(ifp, m, dst);
+               error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst);

                goto done;
        }
 
                goto done;
        }
 


@@ -155,7 +197,9 @@ gotif:
                        mh->m_len = sizeof (struct ip) + olen;
                } else
                        mh->m_len = sizeof (struct ip);
                        mh->m_len = sizeof (struct ip) + olen;
                } else
                        mh->m_len = sizeof (struct ip);

-               mhip->ip_off = off >> 3;
+               mhip->ip_off = (off >> 3) + (ip->ip_off & ~IP_MF);
+               if (ip->ip_off & IP_MF)
+                       mhip->ip_off |= IP_MF;

                if (off + len >= ip->ip_len-hlen)
                        len = mhip->ip_len = ip->ip_len - hlen - off;
                else {
                if (off + len >= ip->ip_len-hlen)
                        len = mhip->ip_len = ip->ip_len - hlen - off;
                else {


@@ -173,12 +217,9 @@ gotif:
                mhip->ip_off = htons((u_short)mhip->ip_off);
                mhip->ip_sum = 0;
                mhip->ip_sum = in_cksum(mh, hlen);
                mhip->ip_off = htons((u_short)mhip->ip_off);
                mhip->ip_sum = 0;
                mhip->ip_sum = in_cksum(mh, hlen);

-               if (error = (*ifp->if_output)(ifp, mh, dst))
+               if (error = (*ifp->if_output)(ifp, mh, (struct sockaddr *)dst))

                        break;
        }
                        break;
        }

-       m_freem(m);
-       goto done;
-

 bad:
        m_freem(m);
 done:
 bad:
        m_freem(m);
 done:


@@ -187,6 +228,48 @@ done:
        return (error);
 }
 
        return (error);
 }
 

+/*
+ * Insert IP options into preformed packet.
+ * Adjust IP destination as required for IP source routing,
+ * as indicated by a non-zero in_addr at the start of the options.
+ */
+struct mbuf *
+ip_insertoptions(m, opt, phlen)
+       register struct mbuf *m;
+       struct mbuf *opt;
+       int *phlen;
+{
+       register struct ipoption *p = mtod(opt, struct ipoption *);
+       struct mbuf *n;
+       register struct ip *ip = mtod(m, struct ip *);
+       unsigned optlen;
+
+       optlen = opt->m_len - sizeof(p->ipopt_dst);
+       if (p->ipopt_dst.s_addr)
+               ip->ip_dst = p->ipopt_dst;
+       if (m->m_off >= MMAXOFF || MMINOFF + optlen > m->m_off) {
+               MGET(n, M_DONTWAIT, MT_HEADER);
+               if (n == 0)
+                       return (m);
+               m->m_len -= sizeof(struct ip);
+               m->m_off += sizeof(struct ip);
+               n->m_next = m;
+               m = n;
+               m->m_off = MMAXOFF - sizeof(struct ip) - optlen;
+               m->m_len = optlen + sizeof(struct ip);
+               bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
+       } else {
+               m->m_off -= optlen;
+               m->m_len += optlen;
+               ovbcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
+       }
+       ip = mtod(m, struct ip *);
+       bcopy((caddr_t)p->ipopt_list, (caddr_t)(ip + 1), (unsigned)optlen);
+       *phlen = sizeof(struct ip) + optlen;
+       ip->ip_len += optlen;
+       return (m);
+}
+

 /*
  * Copy options from ip to jp.
  * If off is 0 all options are copied
 /*
  * Copy options from ip to jp.
  * If off is 0 all options are copied


@@ -209,7 +292,7 @@ ip_optcopy(ip, jp, off)
                if (opt == IPOPT_NOP)
                        optlen = 1;
                else
                if (opt == IPOPT_NOP)
                        optlen = 1;
                else

-                       optlen = cp[1];
+                       optlen = cp[IPOPT_OLEN];

                if (optlen > cnt)                       /* XXX */
                        optlen = cnt;                   /* XXX */
                if (off == 0 || IPOPT_COPIED(opt)) {
                if (optlen > cnt)                       /* XXX */
                        optlen = cnt;                   /* XXX */
                if (off == 0 || IPOPT_COPIED(opt)) {


@@ -221,3 +304,157 @@ ip_optcopy(ip, jp, off)
                *dp++ = IPOPT_EOL;
        return (optlen);
 }
                *dp++ = IPOPT_EOL;
        return (optlen);
 }

+
+/*
+ * IP socket option processing.
+ */
+ip_ctloutput(op, so, level, optname, m)
+       int op;
+       struct socket *so;
+       int level, optname;
+       struct mbuf **m;
+{
+       int error = 0;
+       struct inpcb *inp = sotoinpcb(so);
+
+       if (level != IPPROTO_IP)
+               error = EINVAL;
+       else switch (op) {
+
+       case PRCO_SETOPT:
+               switch (optname) {
+               case IP_OPTIONS:
+                       return (ip_pcbopts(&inp->inp_options, *m));
+
+               default:
+                       error = EINVAL;
+                       break;
+               }
+               break;
+
+       case PRCO_GETOPT:
+               switch (optname) {
+               case IP_OPTIONS:
+                       *m = m_get(M_WAIT, MT_SOOPTS);
+                       if (inp->inp_options) {
+                               (*m)->m_off = inp->inp_options->m_off;
+                               (*m)->m_len = inp->inp_options->m_len;
+                               bcopy(mtod(inp->inp_options, caddr_t),
+                                   mtod(*m, caddr_t), (unsigned)(*m)->m_len);
+                       } else
+                               (*m)->m_len = 0;
+                       break;
+               default:
+                       error = EINVAL;
+                       break;
+               }
+               break;
+       }
+       if (op == PRCO_SETOPT && *m)
+               (void)m_free(*m);
+       return (error);
+}
+
+/*
+ * Set up IP options in pcb for insertion in output packets.
+ * Store in mbuf with pointer in pcbopt, adding pseudo-option
+ * with destination address if source routed.
+ */
+ip_pcbopts(pcbopt, m)
+       struct mbuf **pcbopt;
+       register struct mbuf *m;
+{
+       register cnt, optlen;
+       register u_char *cp;
+       u_char opt;
+
+       /* turn off any old options */
+       if (*pcbopt)
+               (void)m_free(*pcbopt);
+       *pcbopt = 0;
+       if (m == (struct mbuf *)0 || m->m_len == 0) {
+               /*
+                * Only turning off any previous options.
+                */
+               if (m)
+                       (void)m_free(m);
+               return (0);
+       }
+
+#ifndef        vax
+       if (m->m_len % sizeof(long))
+               goto bad;
+#endif
+       /*
+        * IP first-hop destination address will be stored before
+        * actual options; move other options back
+        * and clear it when none present.
+        */
+#if    MAX_IPOPTLEN >= MMAXOFF - MMINOFF
+       if (m->m_off + m->m_len + sizeof(struct in_addr) > MAX_IPOPTLEN)
+               goto bad;
+#else
+       if (m->m_off + m->m_len + sizeof(struct in_addr) > MMAXOFF)
+               goto bad;
+#endif
+       cnt = m->m_len;
+       m->m_len += sizeof(struct in_addr);
+       cp = mtod(m, u_char *) + sizeof(struct in_addr);
+       ovbcopy(mtod(m, caddr_t), (caddr_t)cp, (unsigned)cnt);
+       bzero(mtod(m, caddr_t), sizeof(struct in_addr));
+
+       for (; cnt > 0; cnt -= optlen, cp += optlen) {
+               opt = cp[IPOPT_OPTVAL];
+               if (opt == IPOPT_EOL)
+                       break;
+               if (opt == IPOPT_NOP)
+                       optlen = 1;
+               else {
+                       optlen = cp[IPOPT_OLEN];
+                       if (optlen <= IPOPT_OLEN || optlen > cnt)
+                               goto bad;
+               }
+               switch (opt) {
+
+               default:
+                       break;
+
+               case IPOPT_LSRR:
+               case IPOPT_SSRR:
+                       /*
+                        * user process specifies route as:
+                        *      ->A->B->C->D
+                        * D must be our final destination (but we can't
+                        * check that since we may not have connected yet).
+                        * A is first hop destination, which doesn't appear in
+                        * actual IP option, but is stored before the options.
+                        */
+                       if (optlen < IPOPT_MINOFF - 1 + sizeof(struct in_addr))
+                               goto bad;
+                       m->m_len -= sizeof(struct in_addr);
+                       cnt -= sizeof(struct in_addr);
+                       optlen -= sizeof(struct in_addr);
+                       cp[IPOPT_OLEN] = optlen;
+                       /*
+                        * Move first hop before start of options.
+                        */
+                       bcopy((caddr_t)&cp[IPOPT_OFFSET+1], mtod(m, caddr_t),
+                           sizeof(struct in_addr));
+                       /*
+                        * Then copy rest of options back
+                        * to close up the deleted entry.
+                        */
+                       ovbcopy((caddr_t)(&cp[IPOPT_OFFSET+1] +
+                           sizeof(struct in_addr)),
+                           (caddr_t)&cp[IPOPT_OFFSET+1],
+                           (unsigned)cnt + sizeof(struct in_addr));
+                       break;
+               }
+       }
+       *pcbopt = m;
+       return (0);
+
+bad:
+       (void)m_free(m);
+       return (EINVAL);
+}