net/ipv4/raw.c

/* */
This source file includes following definitions.
min
raw_err
raw_rcv
raw_getfrag
raw_getrawfrag
raw_sendto
raw_sendmsg
raw_close
raw_init
raw_recvmsg
   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 #include <linux/config.h>
  61 
  62 #ifdef CONFIG_IP_MROUTE
  63 struct sock *mroute_socket=NULL;
  64 #endif
  65 
  66 static inline unsigned long min(unsigned long a, unsigned long b)
     /*  */
  67 {
  68         if (a < b) 
  69                 return(a);
  70         return(b);
  71 }
  72 
  73 
  74 /*
  75  *      Raw_err does not currently get called by the icmp module - FIXME:
  76  */
  77  
  78 void raw_err (int type, int code, unsigned char *header, __u32 daddr,
     /*  */
  79          __u32 saddr, struct inet_protocol *protocol)
  80 {
  81         struct sock *sk;
  82    
  83         if (protocol == NULL) 
  84                 return;
  85         sk = (struct sock *) protocol->data;
  86         if (sk == NULL) 
  87                 return;
  88 
  89         /* This is meaningless in raw sockets. */
  90         if (type == ICMP_SOURCE_QUENCH) 
  91         {
  92                 if (sk->cong_window > 1) sk->cong_window = sk->cong_window/2;
  93                 return;
  94         }
  95         
  96         if(type == ICMP_PARAMETERPROB)
  97         {
  98                 sk->err = EPROTO;
  99                 sk->error_report(sk);
 100         }
 101 
 102         if(code<13)
 103         {
 104                 sk->err = icmp_err_convert[code & 0xff].errno;
 105                 sk->error_report(sk);
 106         }
 107         
 108         return;
 109 }
 110 
 111 
 112 /*
 113  *      This should be the easiest of all, all we do is
 114  *      copy it into a buffer. All demultiplexing is done
 115  *      in ip.c
 116  */
 117 
 118 int raw_rcv(struct sock *sk, struct sk_buff *skb, struct device *dev, __u32 saddr, __u32 daddr)
     /*  */
 119 {
 120         /* Now we need to copy this into memory. */
 121         skb->sk = sk;
 122         skb_trim(skb,ntohs(skb->ip_hdr->tot_len));
 123         
 124         skb->h.raw = (unsigned char *) skb->ip_hdr;
 125         skb->dev = dev;
 126         skb->saddr = daddr;
 127         skb->daddr = saddr;
 128         
 129         /* Charge it to the socket. */
 130         
 131         if(sock_queue_rcv_skb(sk,skb)<0)
 132         {
 133                 ip_statistics.IpInDiscards++;
 134                 skb->sk=NULL;
 135                 kfree_skb(skb, FREE_READ);
 136                 return(0);
 137         }
 138 
 139         ip_statistics.IpInDelivers++;
 140         release_sock(sk);
 141         return(0);
 142 }
 143 
 144 /*
 145  *      Send a RAW IP packet.
 146  */
 147 
 148 /*
 149  *      Callback support is trivial for SOCK_RAW
 150  */
 151   
 152 static void raw_getfrag(const void *p, __u32 saddr, char *to, unsigned int offset, unsigned int fraglen)
     /*  */
 153 {
 154         memcpy_fromfs(to, (const unsigned char *)p+offset, fraglen);
 155 }
 156 
 157 /*
 158  *      IPPROTO_RAW needs extra work.
 159  */
 160  
 161 static void raw_getrawfrag(const void *p, __u32 saddr, char *to, unsigned int offset, unsigned int fraglen)
     /*  */
 162 {
 163         memcpy_fromfs(to, (const unsigned char *)p+offset, fraglen);
 164         if(offset==0)
 165         {
 166                 struct iphdr *iph=(struct iphdr *)to;
 167                 iph->saddr=saddr;
 168                 iph->check=0;
 169                 iph->tot_len=htons(fraglen);    /* This is right as you cant frag
 170                                            RAW packets */
 171                 /*
 172                  *      Deliberate breach of modularity to keep 
 173                  *      ip_build_xmit clean (well less messy).
 174                  */
 175                 iph->id = htons(ip_id_count++);
 176                 iph->check=ip_fast_csum((unsigned char *)iph, iph->ihl);
 177         }
 178 }
 179 
 180 static int raw_sendto(struct sock *sk, const unsigned char *from, 
     /*  */
 181         int len, int noblock, unsigned flags, struct sockaddr_in *usin, int addr_len)
 182 {
 183         int err;
 184         struct sockaddr_in sin;
 185 
 186         /*
 187          *      Check the flags. Only MSG_DONTROUTE is permitted.
 188          */
 189 
 190         if (flags & MSG_OOB)            /* Mirror BSD error message compatibility */
 191                 return -EOPNOTSUPP;
 192                          
 193         if (flags & ~MSG_DONTROUTE)
 194                 return(-EINVAL);
 195         /*
 196          *      Get and verify the address. 
 197          */
 198 
 199         if (usin) 
 200         {
 201                 if (addr_len < sizeof(sin)) 
 202                         return(-EINVAL);
 203                 memcpy(&sin, usin, sizeof(sin));
 204                 if (sin.sin_family && sin.sin_family != AF_INET) 
 205                         return(-EINVAL);
 206         }
 207         else 
 208         {
 209                 if (sk->state != TCP_ESTABLISHED) 
 210                         return(-EINVAL);
 211                 sin.sin_family = AF_INET;
 212                 sin.sin_port = sk->protocol;
 213                 sin.sin_addr.s_addr = sk->daddr;
 214         }
 215         if (sin.sin_port == 0) 
 216                 sin.sin_port = sk->protocol;
 217   
 218         if (sin.sin_addr.s_addr == INADDR_ANY)
 219                 sin.sin_addr.s_addr = ip_my_addr();
 220 
 221         if (sk->broadcast == 0 && ip_chk_addr(sin.sin_addr.s_addr)==IS_BROADCAST)
 222                 return -EACCES;
 223 
 224         if(sk->ip_hdrincl)
 225         {
 226                 if(len>65535)
 227                         return -EMSGSIZE;
 228                 err=ip_build_xmit(sk, raw_getrawfrag, from, len, sin.sin_addr.s_addr, 0, sk->opt, flags, sin.sin_port, noblock);
 229         }
 230         else
 231         {
 232                 if(len>65535-sizeof(struct iphdr))
 233                         return -EMSGSIZE;
 234                 err=ip_build_xmit(sk, raw_getfrag, from, len, sin.sin_addr.s_addr, 0, sk->opt, flags, sin.sin_port, noblock);
 235         }
 236         return err<0?err:len;
 237 }
 238 
 239 /*
 240  *      Temporary
 241  */
 242  
 243 static int raw_sendmsg(struct sock *sk, struct msghdr *msg,
     /*  */
 244         int len, int noblock, int flags)
 245 {
 246         if(msg->msg_iovlen==1)
 247                 return raw_sendto(sk,msg->msg_iov[0].iov_base,len, noblock, flags, msg->msg_name, msg->msg_namelen);
 248         else
 249         {
 250                 /*
 251                  *      For awkward cases we linearise the buffer first. In theory this is only frames
 252                  *      whose iovec's don't split on 4 byte boundaries, and soon encrypted stuff (to keep
 253                  *      skip happy). We are a bit more general about it.
 254                  */
 255                  
 256                 unsigned char *buf;
 257                 int fs;
 258                 int err;
 259                 if(len>65515)
 260                         return -EMSGSIZE;
 261                 buf=kmalloc(len, GFP_KERNEL);
 262                 if(buf==NULL)
 263                         return -ENOBUFS;
 264                 memcpy_fromiovec(buf, msg->msg_iov, len);
 265                 fs=get_fs();
 266                 set_fs(get_fs());
 267                 err=raw_sendto(sk,buf,len, noblock, flags, msg->msg_name, msg->msg_namelen);
 268                 set_fs(fs);
 269                 kfree_s(buf,len);
 270                 return err;
 271         }
 272 }
 273 
 274 static void raw_close(struct sock *sk, int timeout)
     /*  */
 275 {
 276         sk->state = TCP_CLOSE;
 277 #ifdef CONFIG_IP_MROUTE 
 278         if(sk==mroute_socket)
 279         {
 280                 mroute_close(sk);
 281                 mroute_socket=NULL;
 282         }
 283 #endif  
 284 }
 285 
 286 
 287 static int raw_init(struct sock *sk)
     /*  */
 288 {
 289         return(0);
 290 }
 291 
 292 
 293 /*
 294  *      This should be easy, if there is something there
 295  *      we return it, otherwise we block.
 296  */
 297 
 298 int raw_recvmsg(struct sock *sk, struct msghdr *msg, int len,
     /*  */
 299      int noblock, int flags,int *addr_len)
 300 {
 301         int copied=0;
 302         struct sk_buff *skb;
 303         int err;
 304         struct sockaddr_in *sin=(struct sockaddr_in *)msg->msg_name;
 305 
 306         if (flags & MSG_OOB)
 307                 return -EOPNOTSUPP;
 308                 
 309         if (sk->shutdown & RCV_SHUTDOWN) 
 310                 return(0);
 311 
 312         if (addr_len) 
 313                 *addr_len=sizeof(*sin);
 314 
 315         skb=skb_recv_datagram(sk,flags,noblock,&err);
 316         if(skb==NULL)
 317                 return err;
 318 
 319         copied = min(len, skb->len);
 320         
 321         skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 322         sk->stamp=skb->stamp;
 323 
 324         /* Copy the address. */
 325         if (sin) 
 326         {
 327                 sin->sin_family = AF_INET;
 328                 sin->sin_addr.s_addr = skb->daddr;
 329         }
 330         skb_free_datagram(skb);
 331         release_sock(sk);
 332         return (copied);
 333 }
 334 
 335 
 336 struct proto raw_prot = {
 337         raw_close,
 338         ip_build_header,
 339         udp_connect,
 340         NULL,
 341         ip_queue_xmit,
 342         NULL,
 343         NULL,
 344         NULL,
 345         NULL,
 346         datagram_select,
 347 #ifdef CONFIG_IP_MROUTE 
 348         ipmr_ioctl,
 349 #else
 350         NULL,
 351 #endif          
 352         raw_init,
 353         NULL,
 354         ip_setsockopt,
 355         ip_getsockopt,
 356         raw_sendmsg,
 357         raw_recvmsg,
 358         NULL,           /* No special bind */
 359         128,
 360         0,
 361         "RAW",
 362         0, 0,
 363         {NULL,}
 364 };
/* */
root/net/ipv4/raw.c

DEFINITIONS
