net/ipv4/raw.c

/* */
This source file includes following definitions.
min
raw_err
raw_rcv
raw_getfrag
raw_getrawfrag
raw_sendto
raw_write
raw_close
raw_init
raw_recvfrom
raw_read
   1 /*
   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  *              RAW - implementation of IP "raw" sockets.
   7  *
   8  * Version:     @(#)raw.c       1.0.4   05/25/93
   9  *
  10  * Authors:     Ross Biro, <bir7@leland.Stanford.Edu>
  11  *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
  12  *
  13  * Fixes:
  14  *              Alan Cox        :       verify_area() fixed up
  15  *              Alan Cox        :       ICMP error handling
  16  *              Alan Cox        :       EMSGSIZE if you send too big a packet
  17  *              Alan Cox        :       Now uses generic datagrams and shared skbuff
  18  *                                      library. No more peek crashes, no more backlogs
  19  *              Alan Cox        :       Checks sk->broadcast.
  20  *              Alan Cox        :       Uses skb_free_datagram/skb_copy_datagram
  21  *              Alan Cox        :       Raw passes ip options too
  22  *              Alan Cox        :       Setsocketopt added
  23  *              Alan Cox        :       Fixed error return for broadcasts
  24  *              Alan Cox        :       Removed wake_up calls
  25  *              Alan Cox        :       Use ttl/tos
  26  *              Alan Cox        :       Cleaned up old debugging
  27  *              Alan Cox        :       Use new kernel side addresses
  28  *      Arnt Gulbrandsen        :       Fixed MSG_DONTROUTE in raw sockets.
  29  *              Alan Cox        :       BSD style RAW socket demultiplexing.
  30  *              Alan Cox        :       Beginnings of mrouted support.
  31  *              Alan Cox        :       Added IP_HDRINCL option.
  32  *
  33  *              This program is free software; you can redistribute it and/or
  34  *              modify it under the terms of the GNU General Public License
  35  *              as published by the Free Software Foundation; either version
  36  *              2 of the License, or (at your option) any later version.
  37  */
  38 #include <asm/system.h>
  39 #include <asm/segment.h>
  40 #include <linux/types.h>
  41 #include <linux/sched.h>
  42 #include <linux/errno.h>
  43 #include <linux/timer.h>
  44 #include <linux/mm.h>
  45 #include <linux/kernel.h>
  46 #include <linux/fcntl.h>
  47 #include <linux/socket.h>
  48 #include <linux/in.h>
  49 #include <linux/inet.h>
  50 #include <linux/netdevice.h>
  51 #include <linux/mroute.h>
  52 #include <net/ip.h>
  53 #include <net/protocol.h>
  54 #include <linux/skbuff.h>
  55 #include <net/sock.h>
  56 #include <net/icmp.h>
  57 #include <net/udp.h>
  58 #include <net/checksum.h>
  59 
  60 #ifdef CONFIG_IP_MROUTE
  61 struct sock *mroute_socket=NULL;
  62 #endif
  63 
  64 static inline unsigned long min(unsigned long a, unsigned long b)
     /*  */
  65 {
  66         if (a < b) 
  67                 return(a);
  68         return(b);
  69 }
  70 
  71 
  72 /*
  73  *      Raw_err does not currently get called by the icmp module - FIXME:
  74  */
  75  
  76 void raw_err (int type, int code, unsigned char *header, __u32 daddr,
     /*  */
  77          __u32 saddr, struct inet_protocol *protocol)
  78 {
  79         struct sock *sk;
  80    
  81         if (protocol == NULL) 
  82                 return;
  83         sk = (struct sock *) protocol->data;
  84         if (sk == NULL) 
  85                 return;
  86 
  87         /* This is meaningless in raw sockets. */
  88         if (type == ICMP_SOURCE_QUENCH) 
  89         {
  90                 if (sk->cong_window > 1) sk->cong_window = sk->cong_window/2;
  91                 return;
  92         }
  93         
  94         if(type == ICMP_PARAMETERPROB)
  95         {
  96                 sk->err = EPROTO;
  97                 sk->error_report(sk);
  98         }
  99 
 100         if(code<13)
 101         {
 102                 sk->err = icmp_err_convert[code & 0xff].errno;
 103                 sk->error_report(sk);
 104         }
 105         
 106         return;
 107 }
 108 
 109 
 110 /*
 111  *      This should be the easiest of all, all we do is
 112  *      copy it into a buffer. All demultiplexing is done
 113  *      in ip.c
 114  */
 115 
 116 int raw_rcv(struct sock *sk, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr)
     /*  */
 117 {
 118         /* Now we need to copy this into memory. */
 119         skb->sk = sk;
 120         skb_trim(skb,ntohs(skb->ip_hdr->tot_len));
 121         
 122         skb->h.raw = (unsigned char *) skb->ip_hdr;
 123         skb->dev = dev;
 124         skb->saddr = daddr;
 125         skb->daddr = saddr;
 126         
 127         /* Charge it to the socket. */
 128         
 129         if(sock_queue_rcv_skb(sk,skb)<0)
 130         {
 131                 ip_statistics.IpInDiscards++;
 132                 skb->sk=NULL;
 133                 kfree_skb(skb, FREE_READ);
 134                 return(0);
 135         }
 136 
 137         ip_statistics.IpInDelivers++;
 138         release_sock(sk);
 139         return(0);
 140 }
 141 
 142 /*
 143  *      Send a RAW IP packet.
 144  */
 145 
 146 /*
 147  *      Callback support is trivial for SOCK_RAW
 148  */
 149   
 150 static void raw_getfrag(const void *p, __u32 saddr, char *to, unsigned int offset, unsigned int fraglen)
     /*  */
 151 {
 152         memcpy_fromfs(to, (const unsigned char *)p+offset, fraglen);
 153 }
 154 
 155 /*
 156  *      IPPROTO_RAW needs extra work.
 157  */
 158  
 159 static void raw_getrawfrag(const void *p, __u32 saddr, char *to, unsigned int offset, unsigned int fraglen)
     /*  */
 160 {
 161         memcpy_fromfs(to, (const unsigned char *)p+offset, fraglen);
 162         if(offset==0)
 163         {
 164                 struct iphdr *iph=(struct iphdr *)to;
 165                 iph->saddr=saddr;
 166                 iph->check=0;
 167                 iph->tot_len=htons(fraglen);    /* This is right as you cant frag
 168                                            RAW packets */
 169                 /*
 170                  *      Deliberate breach of modularity to keep 
 171                  *      ip_build_xmit clean (well less messy).
 172                  */
 173                 iph->id = htons(ip_id_count++);
 174                 iph->check=ip_fast_csum((unsigned char *)iph, iph->ihl);
 175         }
 176 }
 177 
 178 static int raw_sendto(struct sock *sk, const unsigned char *from, 
     /*  */
 179         int len, int noblock, unsigned flags, struct sockaddr_in *usin, int addr_len)
 180 {
 181         int err;
 182         struct sockaddr_in sin;
 183 
 184         /*
 185          *      Check the flags. Only MSG_DONTROUTE is permitted.
 186          */
 187 
 188         if (flags & MSG_OOB)            /* Mirror BSD error message compatibility */
 189                 return -EOPNOTSUPP;
 190                          
 191         if (flags & ~MSG_DONTROUTE)
 192                 return(-EINVAL);
 193         /*
 194          *      Get and verify the address. 
 195          */
 196 
 197         if (usin) 
 198         {
 199                 if (addr_len < sizeof(sin)) 
 200                         return(-EINVAL);
 201                 memcpy(&sin, usin, sizeof(sin));
 202                 if (sin.sin_family && sin.sin_family != AF_INET) 
 203                         return(-EINVAL);
 204         }
 205         else 
 206         {
 207                 if (sk->state != TCP_ESTABLISHED) 
 208                         return(-EINVAL);
 209                 sin.sin_family = AF_INET;
 210                 sin.sin_port = sk->protocol;
 211                 sin.sin_addr.s_addr = sk->daddr;
 212         }
 213         if (sin.sin_port == 0) 
 214                 sin.sin_port = sk->protocol;
 215   
 216         if (sin.sin_addr.s_addr == INADDR_ANY)
 217                 sin.sin_addr.s_addr = ip_my_addr();
 218 
 219         if (sk->broadcast == 0 && ip_chk_addr(sin.sin_addr.s_addr)==IS_BROADCAST)
 220                 return -EACCES;
 221 
 222         if(sk->ip_hdrincl)
 223                 err=ip_build_xmit(sk, raw_getrawfrag, from, len, sin.sin_addr.s_addr, flags, sin.sin_port);
 224         else
 225                 err=ip_build_xmit(sk, raw_getfrag, from, len, sin.sin_addr.s_addr, flags, sin.sin_port);
 226         return err<0?err:len;
 227 }
 228 
 229 
 230 static int raw_write(struct sock *sk, const unsigned char *buff, int len, int noblock,
     /*  */
 231            unsigned flags)
 232 {
 233         return(raw_sendto(sk, buff, len, noblock, flags, NULL, 0));
 234 }
 235 
 236 
 237 static void raw_close(struct sock *sk, int timeout)
     /*  */
 238 {
 239         sk->state = TCP_CLOSE;
 240 #ifdef CONFIG_IP_MROUTE 
 241         if(sk==mroute_socket)
 242         {
 243                 mroute_close(sk);
 244                 mroute_socket=NULL;
 245         }
 246 #endif  
 247 }
 248 
 249 
 250 static int raw_init(struct sock *sk)
     /*  */
 251 {
 252         return(0);
 253 }
 254 
 255 
 256 /*
 257  *      This should be easy, if there is something there
 258  *      we return it, otherwise we block.
 259  */
 260 
 261 int raw_recvfrom(struct sock *sk, unsigned char *to, int len,
     /*  */
 262      int noblock, unsigned flags, struct sockaddr_in *sin,
 263              int *addr_len)
 264 {
 265         int copied=0;
 266         struct sk_buff *skb;
 267         int err;
 268 
 269         if (flags & MSG_OOB)
 270                 return -EOPNOTSUPP;
 271                 
 272         if (sk->shutdown & RCV_SHUTDOWN) 
 273                 return(0);
 274 
 275         if (addr_len) 
 276                 *addr_len=sizeof(*sin);
 277 
 278         skb=skb_recv_datagram(sk,flags,noblock,&err);
 279         if(skb==NULL)
 280                 return err;
 281 
 282         copied = min(len, skb->len);
 283         
 284         skb_copy_datagram(skb, 0, to, copied);
 285         sk->stamp=skb->stamp;
 286 
 287         /* Copy the address. */
 288         if (sin) 
 289         {
 290                 sin->sin_family = AF_INET;
 291                 sin->sin_addr.s_addr = skb->daddr;
 292         }
 293         skb_free_datagram(skb);
 294         release_sock(sk);
 295         return (copied);
 296 }
 297 
 298 
 299 int raw_read (struct sock *sk, unsigned char *buff, int len, int noblock,unsigned flags)
     /*  */
 300 {
 301         return(raw_recvfrom(sk, buff, len, noblock, flags, NULL, NULL));
 302 }
 303 
 304 
 305 struct proto raw_prot = {
 306         sock_wmalloc,
 307         sock_rmalloc,
 308         sock_wfree,
 309         sock_rfree,
 310         sock_rspace,
 311         sock_wspace,
 312         raw_close,
 313         raw_read,
 314         raw_write,
 315         raw_sendto,
 316         raw_recvfrom,
 317         ip_build_header,
 318         udp_connect,
 319         NULL,
 320         ip_queue_xmit,
 321         NULL,
 322         NULL,
 323         NULL,
 324         NULL,
 325         datagram_select,
 326 #ifdef CONFIG_IP_MROUTE 
 327         ipmr_ioctl,
 328 #else
 329         NULL,
 330 #endif          
 331         raw_init,
 332         NULL,
 333         ip_setsockopt,
 334         ip_getsockopt,
 335         128,
 336         0,
 337         "RAW",
 338         0, 0,
 339         {NULL,}
 340 };
/* */
root/net/ipv4/raw.c

DEFINITIONS
