contrib/ipfilter/mln_ipl.c

   1 /*
   2  * Copyright (C) 1993-2001 by Darren Reed.
   3  *
   4  * See the IPFILTER.LICENCE file for details on licencing.
   5  */
   6 /*
   7  * 29/12/94 Added code from Marc Huber <huber@fzi.de> to allow it to allocate
   8  * its own major char number! Way cool patch!
   9  */
  10
  11
  12 #include <sys/param.h>
  13
  14 /*
  15  * Post NetBSD 1.2 has the PFIL interface for packet filters.  This turns
  16  * on those hooks.  We don't need any special mods with this!
  17  */
  18 #if (defined(NetBSD) && (NetBSD > 199609) && (NetBSD <= 1991011)) || \
  19     (defined(NetBSD1_2) && NetBSD1_2 > 1)
  20 # define NETBSD_PF
  21 #endif
  22
  23 #include <sys/systm.h>
  24 #include <sys/conf.h>
  25 #include <sys/file.h>
  26 #include <sys/stat.h>
  27 #include <sys/proc.h>
  28 #include <sys/uio.h>
  29 #include <sys/kernel.h>
  30 #include <sys/vnode.h>
  31 #include <sys/namei.h>
  32 #include <sys/malloc.h>
  33 #include <sys/mount.h>
  34 #include <sys/exec.h>
  35 #include <sys/mbuf.h>
  36 #include <net/if.h>
  37 #include <netinet/in_systm.h>
  38 #include <netinet/in.h>
  39 #include <netinet/ip.h>
  40 #include <net/route.h>
  41 #include <netinet/ip_var.h>
  42 #include <netinet/tcp.h>
  43 #include <netinet/tcpip.h>
  44 #include <sys/lkm.h>
  45 #include "ipl.h"
  46 #include "ip_compat.h"
  47 #include "ip_fil.h"
  48
  49 #if !defined(__NetBSD_Version__) || __NetBSD_Version__ < 103050000
  50 #define vn_lock(v,f) VOP_LOCK(v)
  51 #endif
  52
  53 #if !defined(VOP_LEASE) && defined(LEASE_CHECK)
  54 #define VOP_LEASE       LEASE_CHECK
  55 #endif
  56
  57 #ifndef MIN
  58 #define MIN(a,b)        (((a)<(b))?(a):(b))
  59 #endif
  60
  61
  62 extern  int     lkmenodev __P((void));
  63
  64 #if (NetBSD >= 199706) || (defined(OpenBSD) && (OpenBSD >= 200211))
  65 int     if_ipl_lkmentry __P((struct lkm_table *, int, int));
  66 #else
  67 #if defined(OpenBSD)
  68 int     if_ipl __P((struct lkm_table *, int, int));
  69 #else
  70 int     xxxinit __P((struct lkm_table *, int, int));
  71 #endif
  72 #endif
  73 static  int     ipl_unload __P((void));
  74 static  int     ipl_load __P((void));
  75 static  int     ipl_remove __P((void));
  76 static  int     iplaction __P((struct lkm_table *, int));
  77 static  char    *ipf_devfiles[] = { IPL_NAME, IPL_NAT, IPL_STATE, IPL_AUTH,
  78                                     NULL };
  79
  80
  81 #if (defined(NetBSD1_0) && (NetBSD1_0 > 1)) || \
  82     (defined(NetBSD) && (NetBSD <= 1991011) && (NetBSD >= 199511))
  83 # if defined(__NetBSD__) && (__NetBSD_Version__ >= 106080000)
  84 extern const struct cdevsw ipl_cdevsw;
  85 # else
  86 struct  cdevsw  ipldevsw =
  87 {
  88         iplopen,                /* open */
  89         iplclose,               /* close */
  90         iplread,                /* read */
  91         0,                      /* write */
  92         iplioctl,               /* ioctl */
  93         0,                      /* stop */
  94         0,                      /* tty */
  95         0,                      /* select */
  96         0,                      /* mmap */
  97         NULL                    /* strategy */
  98 };
  99 # endif
 100 #else
 101 struct  cdevsw  ipldevsw =
 102 {
 103         iplopen,                /* open */
 104         iplclose,               /* close */
 105         iplread,                /* read */
 106         (void *)nullop,         /* write */
 107         iplioctl,               /* ioctl */
 108         (void *)nullop,         /* stop */
 109 #ifndef OpenBSD
 110         (void *)nullop,         /* reset */
 111 #endif
 112         (void *)NULL,           /* tty */
 113         (void *)nullop,         /* select */
 114         (void *)nullop,         /* mmap */
 115         NULL                    /* strategy */
 116 };
 117 #endif
 118 int     ipl_major = 0;
 119
 120 #if defined(__NetBSD__) && (__NetBSD_Version__ >= 106080000)
 121 MOD_DEV(IPL_VERSION, "ipl", NULL, -1, &ipl_cdevsw, -1);
 122 #else
 123 MOD_DEV(IPL_VERSION, LM_DT_CHAR, -1, &ipldevsw);
 124 #endif
 125
 126 extern int vd_unuseddev __P((void));
 127 extern struct cdevsw cdevsw[];
 128 extern int nchrdev;
 129
 130
 131 #if (NetBSD >= 199706) || (defined(OpenBSD) && (OpenBSD >= 200211))
 132 int if_ipl_lkmentry(lkmtp, cmd, ver)
 133 #else
 134 #if defined(OpenBSD)
 135 int if_ipl(lkmtp, cmd, ver)
 136 #else
 137 int xxxinit(lkmtp, cmd, ver)
 138 #endif
 139 #endif
 140 struct lkm_table *lkmtp;
 141 int cmd, ver;
 142 {
 143         DISPATCH(lkmtp, cmd, ver, iplaction, iplaction, iplaction);
 144 }
 145
 146 #ifdef OpenBSD
 147 int lkmexists __P((struct lkm_table *)); /* defined in /sys/kern/kern_lkm.c */
 148 #endif
 149
 150 static int iplaction(lkmtp, cmd)
 151 struct lkm_table *lkmtp;
 152 int cmd;
 153 {
 154         struct lkm_dev *args = lkmtp->private.lkm_dev;
 155         int err = 0;
 156 #if !defined(__NetBSD__) || (__NetBSD_Version__ < 106080000)
 157         int i;
 158 #endif
 159
 160         switch (cmd)
 161         {
 162         case LKM_E_LOAD :
 163                 if (lkmexists(lkmtp))
 164                         return EEXIST;
 165
 166 #if !defined(__NetBSD__) || (__NetBSD_Version__ < 106080000)
 167                 for (i = 0; i < nchrdev; i++)
 168                         if (cdevsw[i].d_open == (dev_type_open((*)))lkmenodev ||
 169                             cdevsw[i].d_open == iplopen)
 170                                 break;
 171                 if (i == nchrdev) {
 172                         printf("IP Filter: No free cdevsw slots\n");
 173                         return ENODEV;
 174                 }
 175
 176                 ipl_major = i;
 177                 args->lkm_offset = i;   /* slot in cdevsw[] */
 178 #else
 179                 err = devsw_attach(args->lkm_devname,
 180                                    args->lkm_bdev, &args->lkm_bdevmaj,
 181                                    args->lkm_cdev, &args->lkm_cdevmaj);
 182                 if (err != 0)
 183                         return (err);
 184                 ipl_major = args->lkm_cdevmaj;
 185 #endif
 186                 printf("IP Filter: loaded into slot %d\n", ipl_major);
 187                 return ipl_load();
 188         case LKM_E_UNLOAD :
 189 #if defined(__NetBSD__) && (__NetBSD_Version__ >= 106080000)
 190                 devsw_detach(args->lkm_bdev, args->lkm_cdev);
 191                 args->lkm_bdevmaj = -1;
 192                 args->lkm_cdevmaj = -1;
 193 #endif
 194                 err = ipl_unload();
 195                 if (!err)
 196                         printf("IP Filter: unloaded from slot %d\n",
 197                                ipl_major);
 198                 break;
 199         case LKM_E_STAT :
 200                 break;
 201         default:
 202                 err = EIO;
 203                 break;
 204         }
 205         return err;
 206 }
 207
 208
 209 static int ipl_remove()
 210 {
 211         char *name;
 212         struct nameidata nd;
 213         int error, i;
 214
 215         for (i = 0; (name = ipf_devfiles[i]); i++) {
 216                 NDINIT(&nd, DELETE, LOCKPARENT, UIO_SYSSPACE, name, curproc);
 217                 if ((error = namei(&nd)))
 218                         return (error);
 219                 VOP_LEASE(nd.ni_vp, curproc, curproc->p_ucred, LEASE_WRITE);
 220 #ifdef OpenBSD
 221                 VOP_LOCK(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY, curproc);
 222 #else
 223 # if !defined(__NetBSD_Version__) || (__NetBSD_Version__ < 106000000)
 224                 vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
 225 # endif
 226 #endif
 227                 VOP_LEASE(nd.ni_dvp, curproc, curproc->p_ucred, LEASE_WRITE);
 228                 (void) VOP_REMOVE(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
 229         }
 230         return 0;
 231 }
 232
 233
 234 static int ipl_unload()
 235 {
 236         int error = 0;
 237
 238         /*
 239          * Unloading - remove the filter rule check from the IP
 240          * input/output stream.
 241          */
 242 #if defined(__NetBSD__)
 243         error = ipl_disable();
 244 #else
 245         error = ipldetach();
 246 #endif
 247
 248         if (!error)
 249                 error = ipl_remove();
 250         return error;
 251 }
 252
 253
 254 static int ipl_load()
 255 {
 256         struct nameidata nd;
 257         struct vattr vattr;
 258         int error = 0, fmode = S_IFCHR|0600, i;
 259         char *name;
 260
 261         /*
 262          * XXX Remove existing device nodes prior to creating new ones
 263          * XXX using the assigned LKM device slot's major number.  In a
 264          * XXX perfect world we could use the ones specified by cdevsw[].
 265          */
 266         (void)ipl_remove();
 267
 268         error = ipl_enable();
 269         if (error)
 270                 return error;
 271
 272         for (i = 0; (name = ipf_devfiles[i]); i++) {
 273                 NDINIT(&nd, CREATE, LOCKPARENT, UIO_SYSSPACE, name, curproc);
 274                 if ((error = namei(&nd)))
 275                         return error;
 276                 if (nd.ni_vp != NULL) {
 277                         VOP_ABORTOP(nd.ni_dvp, &nd.ni_cnd);
 278                         if (nd.ni_dvp == nd.ni_vp)
 279                                 vrele(nd.ni_dvp);
 280                         else
 281                                 vput(nd.ni_dvp);
 282                         vrele(nd.ni_vp);
 283                         return (EEXIST);
 284                 }
 285                 VATTR_NULL(&vattr);
 286                 vattr.va_type = VCHR;
 287                 vattr.va_mode = (fmode & 07777);
 288                 vattr.va_rdev = (ipl_major << 8) | i;
 289                 VOP_LEASE(nd.ni_dvp, curproc, curproc->p_ucred, LEASE_WRITE);
 290                 error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
 291                 if (error)
 292                         return error;
 293         }
 294         return error;
 295 }