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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [ipv4/] [ip_options.c] - Blame information for rev 1765

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/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              The options processing module for ip.c
 *
 * Version:     $Id: ip_options.c,v 1.1.1.1 2004-04-15 01:13:55 phoenix Exp $
 *
 * Authors:     A.N.Kuznetsov
 *
 */
 
#include <linux/types.h>
#include <asm/uaccess.h>
#include <linux/skbuff.h>
#include <linux/ip.h>
#include <linux/icmp.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/icmp.h>
 
/*
 * Write options to IP header, record destination address to
 * source route option, address of outgoing interface
 * (we should already know it, so that this  function is allowed be
 * called only after routing decision) and timestamp,
 * if we originate this datagram.
 *
 * daddr is real destination address, next hop is recorded in IP header.
 * saddr is address of outgoing interface.
 */
 
void ip_options_build(struct sk_buff * skb, struct ip_options * opt,
                            u32 daddr, struct rtable *rt, int is_frag)
{
        unsigned char * iph = skb->nh.raw;
 
        memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));
        memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);
        opt = &(IPCB(skb)->opt);
        opt->is_data = 0;
 
        if (opt->srr)
                memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);
 
        if (!is_frag) {
                if (opt->rr_needaddr)
                        ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);
                if (opt->ts_needaddr)
                        ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);
                if (opt->ts_needtime) {
                        struct timeval tv;
                        __u32 midtime;
                        do_gettimeofday(&tv);
                        midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
                        memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);
                }
                return;
        }
        if (opt->rr) {
                memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);
                opt->rr = 0;
                opt->rr_needaddr = 0;
        }
        if (opt->ts) {
                memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);
                opt->ts = 0;
                opt->ts_needaddr = opt->ts_needtime = 0;
        }
}
 
/*
 * Provided (sopt, skb) points to received options,
 * build in dopt compiled option set appropriate for answering.
 * i.e. invert SRR option, copy anothers,
 * and grab room in RR/TS options.
 *
 * NOTE: dopt cannot point to skb.
 */
 
int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)
{
        struct ip_options *sopt;
        unsigned char *sptr, *dptr;
        int soffset, doffset;
        int     optlen;
        u32     daddr;
 
        memset(dopt, 0, sizeof(struct ip_options));
 
        dopt->is_data = 1;
 
        sopt = &(IPCB(skb)->opt);
 
        if (sopt->optlen == 0) {
                dopt->optlen = 0;
                return 0;
        }
 
        sptr = skb->nh.raw;
        dptr = dopt->__data;
 
        if (skb->dst)
                daddr = ((struct rtable*)skb->dst)->rt_spec_dst;
        else
                daddr = skb->nh.iph->daddr;
 
        if (sopt->rr) {
                optlen  = sptr[sopt->rr+1];
                soffset = sptr[sopt->rr+2];
                dopt->rr = dopt->optlen + sizeof(struct iphdr);
                memcpy(dptr, sptr+sopt->rr, optlen);
                if (sopt->rr_needaddr && soffset <= optlen) {
                        if (soffset + 3 > optlen)
                                return -EINVAL;
                        dptr[2] = soffset + 4;
                        dopt->rr_needaddr = 1;
                }
                dptr += optlen;
                dopt->optlen += optlen;
        }
        if (sopt->ts) {
                optlen = sptr[sopt->ts+1];
                soffset = sptr[sopt->ts+2];
                dopt->ts = dopt->optlen + sizeof(struct iphdr);
                memcpy(dptr, sptr+sopt->ts, optlen);
                if (soffset <= optlen) {
                        if (sopt->ts_needaddr) {
                                if (soffset + 3 > optlen)
                                        return -EINVAL;
                                dopt->ts_needaddr = 1;
                                soffset += 4;
                        }
                        if (sopt->ts_needtime) {
                                if (soffset + 3 > optlen)
                                        return -EINVAL;
                                if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {
                                        dopt->ts_needtime = 1;
                                        soffset += 4;
                                } else {
                                        dopt->ts_needtime = 0;
 
                                        if (soffset + 8 <= optlen) {
                                                __u32 addr;
 
                                                memcpy(&addr, sptr+soffset-1, 4);
                                                if (inet_addr_type(addr) != RTN_LOCAL) {
                                                        dopt->ts_needtime = 1;
                                                        soffset += 8;
                                                }
                                        }
                                }
                        }
                        dptr[2] = soffset;
                }
                dptr += optlen;
                dopt->optlen += optlen;
        }
        if (sopt->srr) {
                unsigned char * start = sptr+sopt->srr;
                u32 faddr;
 
                optlen  = start[1];
                soffset = start[2];
                doffset = 0;
                if (soffset > optlen)
                        soffset = optlen + 1;
                soffset -= 4;
                if (soffset > 3) {
                        memcpy(&faddr, &start[soffset-1], 4);
                        for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)
                                memcpy(&dptr[doffset-1], &start[soffset-1], 4);
                        /*
                         * RFC1812 requires to fix illegal source routes.
                         */
                        if (memcmp(&skb->nh.iph->saddr, &start[soffset+3], 4) == 0)
                                doffset -= 4;
                }
                if (doffset > 3) {
                        memcpy(&start[doffset-1], &daddr, 4);
                        dopt->faddr = faddr;
                        dptr[0] = start[0];
                        dptr[1] = doffset+3;
                        dptr[2] = 4;
                        dptr += doffset+3;
                        dopt->srr = dopt->optlen + sizeof(struct iphdr);
                        dopt->optlen += doffset+3;
                        dopt->is_strictroute = sopt->is_strictroute;
                }
        }
        while (dopt->optlen & 3) {
                *dptr++ = IPOPT_END;
                dopt->optlen++;
        }
        return 0;
}
 
/*
 *      Options "fragmenting", just fill options not
 *      allowed in fragments with NOOPs.
 *      Simple and stupid 8), but the most efficient way.
 */
 
void ip_options_fragment(struct sk_buff * skb)
{
        unsigned char * optptr = skb->nh.raw;
        struct ip_options * opt = &(IPCB(skb)->opt);
        int  l = opt->optlen;
        int  optlen;
 
        while (l > 0) {
                switch (*optptr) {
                case IPOPT_END:
                        return;
                case IPOPT_NOOP:
                        l--;
                        optptr++;
                        continue;
                }
                optlen = optptr[1];
                if (optlen<2 || optlen>l)
                  return;
                if (!IPOPT_COPIED(*optptr))
                        memset(optptr, IPOPT_NOOP, optlen);
                l -= optlen;
                optptr += optlen;
        }
        opt->ts = 0;
        opt->rr = 0;
        opt->rr_needaddr = 0;
        opt->ts_needaddr = 0;
        opt->ts_needtime = 0;
        return;
}
 
/*
 * Verify options and fill pointers in struct options.
 * Caller should clear *opt, and set opt->data.
 * If opt == NULL, then skb->data should point to IP header.
 */
 
int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)
{
        int l;
        unsigned char * iph;
        unsigned char * optptr;
        int optlen;
        unsigned char * pp_ptr = NULL;
        struct rtable *rt = skb ? (struct rtable*)skb->dst : NULL;
 
        if (!opt) {
                opt = &(IPCB(skb)->opt);
                memset(opt, 0, sizeof(struct ip_options));
                iph = skb->nh.raw;
                opt->optlen = ((struct iphdr *)iph)->ihl*4 - sizeof(struct iphdr);
                optptr = iph + sizeof(struct iphdr);
                opt->is_data = 0;
        } else {
                optptr = opt->is_data ? opt->__data : (unsigned char*)&(skb->nh.iph[1]);
                iph = optptr - sizeof(struct iphdr);
        }
 
        for (l = opt->optlen; l > 0; ) {
                switch (*optptr) {
                      case IPOPT_END:
                        for (optptr++, l--; l>0; optptr++, l--) {
                                if (*optptr != IPOPT_END) {
                                        *optptr = IPOPT_END;
                                        opt->is_changed = 1;
                                }
                        }
                        goto eol;
                      case IPOPT_NOOP:
                        l--;
                        optptr++;
                        continue;
                }
                optlen = optptr[1];
                if (optlen<2 || optlen>l) {
                        pp_ptr = optptr;
                        goto error;
                }
                switch (*optptr) {
                      case IPOPT_SSRR:
                      case IPOPT_LSRR:
                        if (optlen < 3) {
                                pp_ptr = optptr + 1;
                                goto error;
                        }
                        if (optptr[2] < 4) {
                                pp_ptr = optptr + 2;
                                goto error;
                        }
                        /* NB: cf RFC-1812 5.2.4.1 */
                        if (opt->srr) {
                                pp_ptr = optptr;
                                goto error;
                        }
                        if (!skb) {
                                if (optptr[2] != 4 || optlen < 7 || ((optlen-3) & 3)) {
                                        pp_ptr = optptr + 1;
                                        goto error;
                                }
                                memcpy(&opt->faddr, &optptr[3], 4);
                                if (optlen > 7)
                                        memmove(&optptr[3], &optptr[7], optlen-7);
                        }
                        opt->is_strictroute = (optptr[0] == IPOPT_SSRR);
                        opt->srr = optptr - iph;
                        break;
                      case IPOPT_RR:
                        if (opt->rr) {
                                pp_ptr = optptr;
                                goto error;
                        }
                        if (optlen < 3) {
                                pp_ptr = optptr + 1;
                                goto error;
                        }
                        if (optptr[2] < 4) {
                                pp_ptr = optptr + 2;
                                goto error;
                        }
                        if (optptr[2] <= optlen) {
                                if (optptr[2]+3 > optlen) {
                                        pp_ptr = optptr + 2;
                                        goto error;
                                }
                                if (skb) {
                                        memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
                                        opt->is_changed = 1;
                                }
                                optptr[2] += 4;
                                opt->rr_needaddr = 1;
                        }
                        opt->rr = optptr - iph;
                        break;
                      case IPOPT_TIMESTAMP:
                        if (opt->ts) {
                                pp_ptr = optptr;
                                goto error;
                        }
                        if (optlen < 4) {
                                pp_ptr = optptr + 1;
                                goto error;
                        }
                        if (optptr[2] < 5) {
                                pp_ptr = optptr + 2;
                                goto error;
                        }
                        if (optptr[2] <= optlen) {
                                __u32 * timeptr = NULL;
                                if (optptr[2]+3 > optptr[1]) {
                                        pp_ptr = optptr + 2;
                                        goto error;
                                }
                                switch (optptr[3]&0xF) {
                                      case IPOPT_TS_TSONLY:
                                        opt->ts = optptr - iph;
                                        if (skb)
                                                timeptr = (__u32*)&optptr[optptr[2]-1];
                                        opt->ts_needtime = 1;
                                        optptr[2] += 4;
                                        break;
                                      case IPOPT_TS_TSANDADDR:
                                        if (optptr[2]+7 > optptr[1]) {
                                                pp_ptr = optptr + 2;
                                                goto error;
                                        }
                                        opt->ts = optptr - iph;
                                        if (skb) {
                                                memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);
                                                timeptr = (__u32*)&optptr[optptr[2]+3];
                                        }
                                        opt->ts_needaddr = 1;
                                        opt->ts_needtime = 1;
                                        optptr[2] += 8;
                                        break;
                                      case IPOPT_TS_PRESPEC:
                                        if (optptr[2]+7 > optptr[1]) {
                                                pp_ptr = optptr + 2;
                                                goto error;
                                        }
                                        opt->ts = optptr - iph;
                                        {
                                                u32 addr;
                                                memcpy(&addr, &optptr[optptr[2]-1], 4);
                                                if (inet_addr_type(addr) == RTN_UNICAST)
                                                        break;
                                                if (skb)
                                                        timeptr = (__u32*)&optptr[optptr[2]+3];
                                        }
                                        opt->ts_needtime = 1;
                                        optptr[2] += 8;
                                        break;
                                      default:
                                        if (!skb && !capable(CAP_NET_RAW)) {
                                                pp_ptr = optptr + 3;
                                                goto error;
                                        }
                                        break;
                                }
                                if (timeptr) {
                                        struct timeval tv;
                                        __u32  midtime;
                                        do_gettimeofday(&tv);
                                        midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);
                                        memcpy(timeptr, &midtime, sizeof(__u32));
                                        opt->is_changed = 1;
                                }
                        } else {
                                unsigned overflow = optptr[3]>>4;
                                if (overflow == 15) {
                                        pp_ptr = optptr + 3;
                                        goto error;
                                }
                                opt->ts = optptr - iph;
                                if (skb) {
                                        optptr[3] = (optptr[3]&0xF)|((overflow+1)<<4);
                                        opt->is_changed = 1;
                                }
                        }
                        break;
                      case IPOPT_RA:
                        if (optlen < 4) {
                                pp_ptr = optptr + 1;
                                goto error;
                        }
                        if (optptr[2] == 0 && optptr[3] == 0)
                                opt->router_alert = optptr - iph;
                        break;
                      case IPOPT_SEC:
                      case IPOPT_SID:
                      default:
                        if (!skb && !capable(CAP_NET_RAW)) {
                                pp_ptr = optptr;
                                goto error;
                        }
                        break;
                }
                l -= optlen;
                optptr += optlen;
        }
 
eol:
        if (!pp_ptr)
                return 0;
 
error:
        if (skb) {
                icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));
        }
        return -EINVAL;
}
 
 
/*
 *      Undo all the changes done by ip_options_compile().
 */
 
void ip_options_undo(struct ip_options * opt)
{
        if (opt->srr) {
                unsigned  char * optptr = opt->__data+opt->srr-sizeof(struct  iphdr);
                memmove(optptr+7, optptr+3, optptr[1]-7);
                memcpy(optptr+3, &opt->faddr, 4);
        }
        if (opt->rr_needaddr) {
                unsigned  char * optptr = opt->__data+opt->rr-sizeof(struct  iphdr);
                optptr[2] -= 4;
                memset(&optptr[optptr[2]-1], 0, 4);
        }
        if (opt->ts) {
                unsigned  char * optptr = opt->__data+opt->ts-sizeof(struct  iphdr);
                if (opt->ts_needtime) {
                        optptr[2] -= 4;
                        memset(&optptr[optptr[2]-1], 0, 4);
                        if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)
                                optptr[2] -= 4;
                }
                if (opt->ts_needaddr) {
                        optptr[2] -= 4;
                        memset(&optptr[optptr[2]-1], 0, 4);
                }
        }
}
 
int ip_options_get(struct ip_options **optp, unsigned char *data, int optlen, int user)
{
        struct ip_options *opt;
 
        opt = kmalloc(sizeof(struct ip_options)+((optlen+3)&~3), GFP_KERNEL);
        if (!opt)
                return -ENOMEM;
        memset(opt, 0, sizeof(struct ip_options));
        if (optlen) {
                if (user) {
                        if (copy_from_user(opt->__data, data, optlen)) {
                                kfree(opt);
                                return -EFAULT;
                        }
                } else
                        memcpy(opt->__data, data, optlen);
        }
        while (optlen & 3)
                opt->__data[optlen++] = IPOPT_END;
        opt->optlen = optlen;
        opt->is_data = 1;
        opt->is_setbyuser = 1;
        if (optlen && ip_options_compile(opt, NULL)) {
                kfree(opt);
                return -EINVAL;
        }
        *optp = opt;
        return 0;
}
 
void ip_forward_options(struct sk_buff *skb)
{
        struct   ip_options * opt       = &(IPCB(skb)->opt);
        unsigned char * optptr;
        struct rtable *rt = (struct rtable*)skb->dst;
        unsigned char *raw = skb->nh.raw;
 
        if (opt->rr_needaddr) {
                optptr = (unsigned char *)raw + opt->rr;
                ip_rt_get_source(&optptr[optptr[2]-5], rt);
                opt->is_changed = 1;
        }
        if (opt->srr_is_hit) {
                int srrptr, srrspace;
 
                optptr = raw + opt->srr;
 
                for ( srrptr=optptr[2], srrspace = optptr[1];
                     srrptr <= srrspace;
                     srrptr += 4
                     ) {
                        if (srrptr + 3 > srrspace)
                                break;
                        if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)
                                break;
                }
                if (srrptr + 3 <= srrspace) {
                        opt->is_changed = 1;
                        ip_rt_get_source(&optptr[srrptr-1], rt);
                        skb->nh.iph->daddr = rt->rt_dst;
                        optptr[2] = srrptr+4;
                } else if (net_ratelimit())
                        printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");
                if (opt->ts_needaddr) {
                        optptr = raw + opt->ts;
                        ip_rt_get_source(&optptr[optptr[2]-9], rt);
                        opt->is_changed = 1;
                }
        }
        if (opt->is_changed) {
                opt->is_changed = 0;
                ip_send_check(skb->nh.iph);
        }
}
 
int ip_options_rcv_srr(struct sk_buff *skb)
{
        struct ip_options *opt = &(IPCB(skb)->opt);
        int srrspace, srrptr;
        u32 nexthop;
        struct iphdr *iph = skb->nh.iph;
        unsigned char * optptr = skb->nh.raw + opt->srr;
        struct rtable *rt = (struct rtable*)skb->dst;
        struct rtable *rt2;
        int err;
 
        if (!opt->srr)
                return 0;
 
        if (skb->pkt_type != PACKET_HOST)
                return -EINVAL;
        if (rt->rt_type == RTN_UNICAST) {
                if (!opt->is_strictroute)
                        return 0;
                icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));
                return -EINVAL;
        }
        if (rt->rt_type != RTN_LOCAL)
                return -EINVAL;
 
        for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {
                if (srrptr + 3 > srrspace) {
                        icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));
                        return -EINVAL;
                }
                memcpy(&nexthop, &optptr[srrptr-1], 4);
 
                rt = (struct rtable*)skb->dst;
                skb->dst = NULL;
                err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);
                rt2 = (struct rtable*)skb->dst;
                if (err || (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {
                        ip_rt_put(rt2);
                        skb->dst = &rt->u.dst;
                        return -EINVAL;
                }
                ip_rt_put(rt);
                if (rt2->rt_type != RTN_LOCAL)
                        break;
                /* Superfast 8) loopback forward */
                memcpy(&iph->daddr, &optptr[srrptr-1], 4);
                opt->is_changed = 1;
        }
        if (srrptr <= srrspace) {
                opt->srr_is_hit = 1;
                opt->is_changed = 1;
        }
        return 0;
}

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[/] [or1k/] [trunk/] [linux/] [linux-2.4/] [net/] [ipv4/] [ip_options.c] - Blame information for rev 1765

Line No.	Rev	Author	Line
1	1275	phoenix	`/*`
2			`* INET An implementation of the TCP/IP protocol suite for the LINUX`
3			`* operating system. INET is implemented using the BSD Socket`
4			`* interface as the means of communication with the user level.`
5			`*`
6			`* The options processing module for ip.c`
7			`*`
8			`* Version: $Id: ip_options.c,v 1.1.1.1 2004-04-15 01:13:55 phoenix Exp $`
9			`*`
10			`* Authors: A.N.Kuznetsov`
11			`*`
12			`*/`
13
14			`#include <linux/types.h>`
15			`#include <asm/uaccess.h>`
16			`#include <linux/skbuff.h>`
17			`#include <linux/ip.h>`
18			`#include <linux/icmp.h>`
19			`#include <linux/netdevice.h>`
20			`#include <linux/rtnetlink.h>`
21			`#include <net/sock.h>`
22			`#include <net/ip.h>`
23			`#include <net/icmp.h>`
24
25			`/*`
26			`* Write options to IP header, record destination address to`
27			`* source route option, address of outgoing interface`
28			`* (we should already know it, so that this function is allowed be`
29			`* called only after routing decision) and timestamp,`
30			`* if we originate this datagram.`
31			`*`
32			`* daddr is real destination address, next hop is recorded in IP header.`
33			`* saddr is address of outgoing interface.`
34			`*/`
35
36			`void ip_options_build(struct sk_buff * skb, struct ip_options * opt,`
37			`u32 daddr, struct rtable *rt, int is_frag)`
38			`{`
39			`unsigned char * iph = skb->nh.raw;`
40
41			`memcpy(&(IPCB(skb)->opt), opt, sizeof(struct ip_options));`
42			`memcpy(iph+sizeof(struct iphdr), opt->__data, opt->optlen);`
43			`opt = &(IPCB(skb)->opt);`
44			`opt->is_data = 0;`
45
46			`if (opt->srr)`
47			`memcpy(iph+opt->srr+iph[opt->srr+1]-4, &daddr, 4);`
48
49			`if (!is_frag) {`
50			`if (opt->rr_needaddr)`
51			`ip_rt_get_source(iph+opt->rr+iph[opt->rr+2]-5, rt);`
52			`if (opt->ts_needaddr)`
53			`ip_rt_get_source(iph+opt->ts+iph[opt->ts+2]-9, rt);`
54			`if (opt->ts_needtime) {`
55			`struct timeval tv;`
56			`__u32 midtime;`
57			`do_gettimeofday(&tv);`
58			`midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);`
59			`memcpy(iph+opt->ts+iph[opt->ts+2]-5, &midtime, 4);`
60			`}`
61			`return;`
62			`}`
63			`if (opt->rr) {`
64			`memset(iph+opt->rr, IPOPT_NOP, iph[opt->rr+1]);`
65			`opt->rr = 0;`
66			`opt->rr_needaddr = 0;`
67			`}`
68			`if (opt->ts) {`
69			`memset(iph+opt->ts, IPOPT_NOP, iph[opt->ts+1]);`
70			`opt->ts = 0;`
71			`opt->ts_needaddr = opt->ts_needtime = 0;`
72			`}`
73			`}`
74
75			`/*`
76			`* Provided (sopt, skb) points to received options,`
77			`* build in dopt compiled option set appropriate for answering.`
78			`* i.e. invert SRR option, copy anothers,`
79			`* and grab room in RR/TS options.`
80			`*`
81			`* NOTE: dopt cannot point to skb.`
82			`*/`
83
84			`int ip_options_echo(struct ip_options * dopt, struct sk_buff * skb)`
85			`{`
86			`struct ip_options *sopt;`
87			`unsigned char sptr, dptr;`
88			`int soffset, doffset;`
89			`int optlen;`
90			`u32 daddr;`
91
92			`memset(dopt, 0, sizeof(struct ip_options));`
93
94			`dopt->is_data = 1;`
95
96			`sopt = &(IPCB(skb)->opt);`
97
98			`if (sopt->optlen == 0) {`
99			`dopt->optlen = 0;`
100			`return 0;`
101			`}`
102
103			`sptr = skb->nh.raw;`
104			`dptr = dopt->__data;`
105
106			`if (skb->dst)`
107			`daddr = ((struct rtable*)skb->dst)->rt_spec_dst;`
108			`else`
109			`daddr = skb->nh.iph->daddr;`
110
111			`if (sopt->rr) {`
112			`optlen = sptr[sopt->rr+1];`
113			`soffset = sptr[sopt->rr+2];`
114			`dopt->rr = dopt->optlen + sizeof(struct iphdr);`
115			`memcpy(dptr, sptr+sopt->rr, optlen);`
116			`if (sopt->rr_needaddr && soffset <= optlen) {`
117			`if (soffset + 3 > optlen)`
118			`return -EINVAL;`
119			`dptr[2] = soffset + 4;`
120			`dopt->rr_needaddr = 1;`
121			`}`
122			`dptr += optlen;`
123			`dopt->optlen += optlen;`
124			`}`
125			`if (sopt->ts) {`
126			`optlen = sptr[sopt->ts+1];`
127			`soffset = sptr[sopt->ts+2];`
128			`dopt->ts = dopt->optlen + sizeof(struct iphdr);`
129			`memcpy(dptr, sptr+sopt->ts, optlen);`
130			`if (soffset <= optlen) {`
131			`if (sopt->ts_needaddr) {`
132			`if (soffset + 3 > optlen)`
133			`return -EINVAL;`
134			`dopt->ts_needaddr = 1;`
135			`soffset += 4;`
136			`}`
137			`if (sopt->ts_needtime) {`
138			`if (soffset + 3 > optlen)`
139			`return -EINVAL;`
140			`if ((dptr[3]&0xF) != IPOPT_TS_PRESPEC) {`
141			`dopt->ts_needtime = 1;`
142			`soffset += 4;`
143			`} else {`
144			`dopt->ts_needtime = 0;`
145
146			`if (soffset + 8 <= optlen) {`
147			`__u32 addr;`
148
149			`memcpy(&addr, sptr+soffset-1, 4);`
150			`if (inet_addr_type(addr) != RTN_LOCAL) {`
151			`dopt->ts_needtime = 1;`
152			`soffset += 8;`
153			`}`
154			`}`
155			`}`
156			`}`
157			`dptr[2] = soffset;`
158			`}`
159			`dptr += optlen;`
160			`dopt->optlen += optlen;`
161			`}`
162			`if (sopt->srr) {`
163			`unsigned char * start = sptr+sopt->srr;`
164			`u32 faddr;`
165
166			`optlen = start[1];`
167			`soffset = start[2];`
168			`doffset = 0;`
169			`if (soffset > optlen)`
170			`soffset = optlen + 1;`
171			`soffset -= 4;`
172			`if (soffset > 3) {`
173			`memcpy(&faddr, &start[soffset-1], 4);`
174			`for (soffset-=4, doffset=4; soffset > 3; soffset-=4, doffset+=4)`
175			`memcpy(&dptr[doffset-1], &start[soffset-1], 4);`
176			`/*`
177			`* RFC1812 requires to fix illegal source routes.`
178			`*/`
179			`if (memcmp(&skb->nh.iph->saddr, &start[soffset+3], 4) == 0)`
180			`doffset -= 4;`
181			`}`
182			`if (doffset > 3) {`
183			`memcpy(&start[doffset-1], &daddr, 4);`
184			`dopt->faddr = faddr;`
185			`dptr[0] = start[0];`
186			`dptr[1] = doffset+3;`
187			`dptr[2] = 4;`
188			`dptr += doffset+3;`
189			`dopt->srr = dopt->optlen + sizeof(struct iphdr);`
190			`dopt->optlen += doffset+3;`
191			`dopt->is_strictroute = sopt->is_strictroute;`
192			`}`
193			`}`
194			`while (dopt->optlen & 3) {`
195			`*dptr++ = IPOPT_END;`
196			`dopt->optlen++;`
197			`}`
198			`return 0;`
199			`}`
200
201			`/*`
202			`* Options "fragmenting", just fill options not`
203			`* allowed in fragments with NOOPs.`
204			`* Simple and stupid 8), but the most efficient way.`
205			`*/`
206
207			`void ip_options_fragment(struct sk_buff * skb)`
208			`{`
209			`unsigned char * optptr = skb->nh.raw;`
210			`struct ip_options * opt = &(IPCB(skb)->opt);`
211			`int l = opt->optlen;`
212			`int optlen;`
213
214			`while (l > 0) {`
215			`switch (*optptr) {`
216			`case IPOPT_END:`
217			`return;`
218			`case IPOPT_NOOP:`
219			`l--;`
220			`optptr++;`
221			`continue;`
222			`}`
223			`optlen = optptr[1];`
224			`if (optlen<2 \|\| optlen>l)`
225			`return;`
226			`if (!IPOPT_COPIED(*optptr))`
227			`memset(optptr, IPOPT_NOOP, optlen);`
228			`l -= optlen;`
229			`optptr += optlen;`
230			`}`
231			`opt->ts = 0;`
232			`opt->rr = 0;`
233			`opt->rr_needaddr = 0;`
234			`opt->ts_needaddr = 0;`
235			`opt->ts_needtime = 0;`
236			`return;`
237			`}`
238
239			`/*`
240			`* Verify options and fill pointers in struct options.`
241			`* Caller should clear *opt, and set opt->data.`
242			`* If opt == NULL, then skb->data should point to IP header.`
243			`*/`
244
245			`int ip_options_compile(struct ip_options * opt, struct sk_buff * skb)`
246			`{`
247			`int l;`
248			`unsigned char * iph;`
249			`unsigned char * optptr;`
250			`int optlen;`
251			`unsigned char * pp_ptr = NULL;`
252			`struct rtable rt = skb ? (struct rtable)skb->dst : NULL;`
253
254			`if (!opt) {`
255			`opt = &(IPCB(skb)->opt);`
256			`memset(opt, 0, sizeof(struct ip_options));`
257			`iph = skb->nh.raw;`
258			`opt->optlen = ((struct iphdr )iph)->ihl4 - sizeof(struct iphdr);`
259			`optptr = iph + sizeof(struct iphdr);`
260			`opt->is_data = 0;`
261			`} else {`
262			`optptr = opt->is_data ? opt->__data : (unsigned char*)&(skb->nh.iph[1]);`
263			`iph = optptr - sizeof(struct iphdr);`
264			`}`
265
266			`for (l = opt->optlen; l > 0; ) {`
267			`switch (*optptr) {`
268			`case IPOPT_END:`
269			`for (optptr++, l--; l>0; optptr++, l--) {`
270			`if (*optptr != IPOPT_END) {`
271			`*optptr = IPOPT_END;`
272			`opt->is_changed = 1;`
273			`}`
274			`}`
275			`goto eol;`
276			`case IPOPT_NOOP:`
277			`l--;`
278			`optptr++;`
279			`continue;`
280			`}`
281			`optlen = optptr[1];`
282			`if (optlen<2 \|\| optlen>l) {`
283			`pp_ptr = optptr;`
284			`goto error;`
285			`}`
286			`switch (*optptr) {`
287			`case IPOPT_SSRR:`
288			`case IPOPT_LSRR:`
289			`if (optlen < 3) {`
290			`pp_ptr = optptr + 1;`
291			`goto error;`
292			`}`
293			`if (optptr[2] < 4) {`
294			`pp_ptr = optptr + 2;`
295			`goto error;`
296			`}`
297			`/* NB: cf RFC-1812 5.2.4.1 */`
298			`if (opt->srr) {`
299			`pp_ptr = optptr;`
300			`goto error;`
301			`}`
302			`if (!skb) {`
303			`if (optptr[2] != 4 \|\| optlen < 7 \|\| ((optlen-3) & 3)) {`
304			`pp_ptr = optptr + 1;`
305			`goto error;`
306			`}`
307			`memcpy(&opt->faddr, &optptr[3], 4);`
308			`if (optlen > 7)`
309			`memmove(&optptr[3], &optptr[7], optlen-7);`
310			`}`
311			`opt->is_strictroute = (optptr[0] == IPOPT_SSRR);`
312			`opt->srr = optptr - iph;`
313			`break;`
314			`case IPOPT_RR:`
315			`if (opt->rr) {`
316			`pp_ptr = optptr;`
317			`goto error;`
318			`}`
319			`if (optlen < 3) {`
320			`pp_ptr = optptr + 1;`
321			`goto error;`
322			`}`
323			`if (optptr[2] < 4) {`
324			`pp_ptr = optptr + 2;`
325			`goto error;`
326			`}`
327			`if (optptr[2] <= optlen) {`
328			`if (optptr[2]+3 > optlen) {`
329			`pp_ptr = optptr + 2;`
330			`goto error;`
331			`}`
332			`if (skb) {`
333			`memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);`
334			`opt->is_changed = 1;`
335			`}`
336			`optptr[2] += 4;`
337			`opt->rr_needaddr = 1;`
338			`}`
339			`opt->rr = optptr - iph;`
340			`break;`
341			`case IPOPT_TIMESTAMP:`
342			`if (opt->ts) {`
343			`pp_ptr = optptr;`
344			`goto error;`
345			`}`
346			`if (optlen < 4) {`
347			`pp_ptr = optptr + 1;`
348			`goto error;`
349			`}`
350			`if (optptr[2] < 5) {`
351			`pp_ptr = optptr + 2;`
352			`goto error;`
353			`}`
354			`if (optptr[2] <= optlen) {`
355			`__u32 * timeptr = NULL;`
356			`if (optptr[2]+3 > optptr[1]) {`
357			`pp_ptr = optptr + 2;`
358			`goto error;`
359			`}`
360			`switch (optptr[3]&0xF) {`
361			`case IPOPT_TS_TSONLY:`
362			`opt->ts = optptr - iph;`
363			`if (skb)`
364			`timeptr = (__u32*)&optptr[optptr[2]-1];`
365			`opt->ts_needtime = 1;`
366			`optptr[2] += 4;`
367			`break;`
368			`case IPOPT_TS_TSANDADDR:`
369			`if (optptr[2]+7 > optptr[1]) {`
370			`pp_ptr = optptr + 2;`
371			`goto error;`
372			`}`
373			`opt->ts = optptr - iph;`
374			`if (skb) {`
375			`memcpy(&optptr[optptr[2]-1], &rt->rt_spec_dst, 4);`
376			`timeptr = (__u32*)&optptr[optptr[2]+3];`
377			`}`
378			`opt->ts_needaddr = 1;`
379			`opt->ts_needtime = 1;`
380			`optptr[2] += 8;`
381			`break;`
382			`case IPOPT_TS_PRESPEC:`
383			`if (optptr[2]+7 > optptr[1]) {`
384			`pp_ptr = optptr + 2;`
385			`goto error;`
386			`}`
387			`opt->ts = optptr - iph;`
388			`{`
389			`u32 addr;`
390			`memcpy(&addr, &optptr[optptr[2]-1], 4);`
391			`if (inet_addr_type(addr) == RTN_UNICAST)`
392			`break;`
393			`if (skb)`
394			`timeptr = (__u32*)&optptr[optptr[2]+3];`
395			`}`
396			`opt->ts_needtime = 1;`
397			`optptr[2] += 8;`
398			`break;`
399			`default:`
400			`if (!skb && !capable(CAP_NET_RAW)) {`
401			`pp_ptr = optptr + 3;`
402			`goto error;`
403			`}`
404			`break;`
405			`}`
406			`if (timeptr) {`
407			`struct timeval tv;`
408			`__u32 midtime;`
409			`do_gettimeofday(&tv);`
410			`midtime = htonl((tv.tv_sec % 86400) * 1000 + tv.tv_usec / 1000);`
411			`memcpy(timeptr, &midtime, sizeof(__u32));`
412			`opt->is_changed = 1;`
413			`}`
414			`} else {`
415			`unsigned overflow = optptr[3]>>4;`
416			`if (overflow == 15) {`
417			`pp_ptr = optptr + 3;`
418			`goto error;`
419			`}`
420			`opt->ts = optptr - iph;`
421			`if (skb) {`
422			`optptr[3] = (optptr[3]&0xF)\|((overflow+1)<<4);`
423			`opt->is_changed = 1;`
424			`}`
425			`}`
426			`break;`
427			`case IPOPT_RA:`
428			`if (optlen < 4) {`
429			`pp_ptr = optptr + 1;`
430			`goto error;`
431			`}`
432			`if (optptr[2] == 0 && optptr[3] == 0)`
433			`opt->router_alert = optptr - iph;`
434			`break;`
435			`case IPOPT_SEC:`
436			`case IPOPT_SID:`
437			`default:`
438			`if (!skb && !capable(CAP_NET_RAW)) {`
439			`pp_ptr = optptr;`
440			`goto error;`
441			`}`
442			`break;`
443			`}`
444			`l -= optlen;`
445			`optptr += optlen;`
446			`}`
447
448			`eol:`
449			`if (!pp_ptr)`
450			`return 0;`
451
452			`error:`
453			`if (skb) {`
454			`icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((pp_ptr-iph)<<24));`
455			`}`
456			`return -EINVAL;`
457			`}`
458
459
460			`/*`
461			`* Undo all the changes done by ip_options_compile().`
462			`*/`
463
464			`void ip_options_undo(struct ip_options * opt)`
465			`{`
466			`if (opt->srr) {`
467			`unsigned char * optptr = opt->__data+opt->srr-sizeof(struct iphdr);`
468			`memmove(optptr+7, optptr+3, optptr[1]-7);`
469			`memcpy(optptr+3, &opt->faddr, 4);`
470			`}`
471			`if (opt->rr_needaddr) {`
472			`unsigned char * optptr = opt->__data+opt->rr-sizeof(struct iphdr);`
473			`optptr[2] -= 4;`
474			`memset(&optptr[optptr[2]-1], 0, 4);`
475			`}`
476			`if (opt->ts) {`
477			`unsigned char * optptr = opt->__data+opt->ts-sizeof(struct iphdr);`
478			`if (opt->ts_needtime) {`
479			`optptr[2] -= 4;`
480			`memset(&optptr[optptr[2]-1], 0, 4);`
481			`if ((optptr[3]&0xF) == IPOPT_TS_PRESPEC)`
482			`optptr[2] -= 4;`
483			`}`
484			`if (opt->ts_needaddr) {`
485			`optptr[2] -= 4;`
486			`memset(&optptr[optptr[2]-1], 0, 4);`
487			`}`
488			`}`
489			`}`
490
491			`int ip_options_get(struct ip_options *optp, unsigned char data, int optlen, int user)`
492			`{`
493			`struct ip_options *opt;`
494
495			`opt = kmalloc(sizeof(struct ip_options)+((optlen+3)&~3), GFP_KERNEL);`
496			`if (!opt)`
497			`return -ENOMEM;`
498			`memset(opt, 0, sizeof(struct ip_options));`
499			`if (optlen) {`
500			`if (user) {`
501			`if (copy_from_user(opt->__data, data, optlen)) {`
502			`kfree(opt);`
503			`return -EFAULT;`
504			`}`
505			`} else`
506			`memcpy(opt->__data, data, optlen);`
507			`}`
508			`while (optlen & 3)`
509			`opt->__data[optlen++] = IPOPT_END;`
510			`opt->optlen = optlen;`
511			`opt->is_data = 1;`
512			`opt->is_setbyuser = 1;`
513			`if (optlen && ip_options_compile(opt, NULL)) {`
514			`kfree(opt);`
515			`return -EINVAL;`
516			`}`
517			`*optp = opt;`
518			`return 0;`
519			`}`
520
521			`void ip_forward_options(struct sk_buff *skb)`
522			`{`
523			`struct ip_options * opt = &(IPCB(skb)->opt);`
524			`unsigned char * optptr;`
525			`struct rtable rt = (struct rtable)skb->dst;`
526			`unsigned char *raw = skb->nh.raw;`
527
528			`if (opt->rr_needaddr) {`
529			`optptr = (unsigned char *)raw + opt->rr;`
530			`ip_rt_get_source(&optptr[optptr[2]-5], rt);`
531			`opt->is_changed = 1;`
532			`}`
533			`if (opt->srr_is_hit) {`
534			`int srrptr, srrspace;`
535
536			`optptr = raw + opt->srr;`
537
538			`for ( srrptr=optptr[2], srrspace = optptr[1];`
539			`srrptr <= srrspace;`
540			`srrptr += 4`
541			`) {`
542			`if (srrptr + 3 > srrspace)`
543			`break;`
544			`if (memcmp(&rt->rt_dst, &optptr[srrptr-1], 4) == 0)`
545			`break;`
546			`}`
547			`if (srrptr + 3 <= srrspace) {`
548			`opt->is_changed = 1;`
549			`ip_rt_get_source(&optptr[srrptr-1], rt);`
550			`skb->nh.iph->daddr = rt->rt_dst;`
551			`optptr[2] = srrptr+4;`
552			`} else if (net_ratelimit())`
553			`printk(KERN_CRIT "ip_forward(): Argh! Destination lost!\n");`
554			`if (opt->ts_needaddr) {`
555			`optptr = raw + opt->ts;`
556			`ip_rt_get_source(&optptr[optptr[2]-9], rt);`
557			`opt->is_changed = 1;`
558			`}`
559			`}`
560			`if (opt->is_changed) {`
561			`opt->is_changed = 0;`
562			`ip_send_check(skb->nh.iph);`
563			`}`
564			`}`
565
566			`int ip_options_rcv_srr(struct sk_buff *skb)`
567			`{`
568			`struct ip_options *opt = &(IPCB(skb)->opt);`
569			`int srrspace, srrptr;`
570			`u32 nexthop;`
571			`struct iphdr *iph = skb->nh.iph;`
572			`unsigned char * optptr = skb->nh.raw + opt->srr;`
573			`struct rtable rt = (struct rtable)skb->dst;`
574			`struct rtable *rt2;`
575			`int err;`
576
577			`if (!opt->srr)`
578			`return 0;`
579
580			`if (skb->pkt_type != PACKET_HOST)`
581			`return -EINVAL;`
582			`if (rt->rt_type == RTN_UNICAST) {`
583			`if (!opt->is_strictroute)`
584			`return 0;`
585			`icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl(16<<24));`
586			`return -EINVAL;`
587			`}`
588			`if (rt->rt_type != RTN_LOCAL)`
589			`return -EINVAL;`
590
591			`for (srrptr=optptr[2], srrspace = optptr[1]; srrptr <= srrspace; srrptr += 4) {`
592			`if (srrptr + 3 > srrspace) {`
593			`icmp_send(skb, ICMP_PARAMETERPROB, 0, htonl((opt->srr+2)<<24));`
594			`return -EINVAL;`
595			`}`
596			`memcpy(&nexthop, &optptr[srrptr-1], 4);`
597
598			`rt = (struct rtable*)skb->dst;`
599			`skb->dst = NULL;`
600			`err = ip_route_input(skb, nexthop, iph->saddr, iph->tos, skb->dev);`
601			`rt2 = (struct rtable*)skb->dst;`
602			`if (err \|\| (rt2->rt_type != RTN_UNICAST && rt2->rt_type != RTN_LOCAL)) {`
603			`ip_rt_put(rt2);`
604			`skb->dst = &rt->u.dst;`
605			`return -EINVAL;`
606			`}`
607			`ip_rt_put(rt);`
608			`if (rt2->rt_type != RTN_LOCAL)`
609			`break;`
610			`/* Superfast 8) loopback forward */`
611			`memcpy(&iph->daddr, &optptr[srrptr-1], 4);`
612			`opt->is_changed = 1;`
613			`}`
614			`if (srrptr <= srrspace) {`
615			`opt->srr_is_hit = 1;`
616			`opt->is_changed = 1;`
617			`}`
618			`return 0;`
619			`}`