utils/mountd/cache.c

   1
   2 /*
   3  * Handle communication with knfsd internal cache
   4  *
   5  * We open /proc/net/rpc/{auth.unix.ip,nfsd.export,nfsd.fh}/channel
   6  * and listen for requests (using my_svc_run)
   7  *
   8  */
   9
  10 #ifdef HAVE_CONFIG_H
  11 #include <config.h>
  12 #endif
  13
  14 #include <sys/types.h>
  15 #include <sys/select.h>
  16 #include <sys/stat.h>
  17 #include <time.h>
  18 #include <netinet/in.h>
  19 #include <arpa/inet.h>
  20 #include <unistd.h>
  21 #include <fcntl.h>
  22 #include <errno.h>
  23 #include <ctype.h>
  24 #include "misc.h"
  25 #include "nfslib.h"
  26 #include "exportfs.h"
  27 #include "mountd.h"
  28 #include "xmalloc.h"
  29
  30 /*
  31  * Support routines for text-based upcalls.
  32  * Fields are separated by spaces.
  33  * Fields are either mangled to quote space tab newline slosh with slosh
  34  * or a hexified with a leading \x
  35  * Record is terminated with newline.
  36  *
  37  */
  38 int cache_export_ent(char *domain, struct exportent *exp);
  39
  40
  41 char *lbuf  = NULL;
  42 int lbuflen = 0;
  43
  44 void auth_unix_ip(FILE *f)
  45 {
  46         /* requests are
  47          *  class IP-ADDR
  48          * Ignore if class != "nfsd"
  49          * Otherwise find domainname and write back:
  50          *
  51          *  "nfsd" IP-ADDR expiry domainname
  52          */
  53         char *cp;
  54         char class[20];
  55         char ipaddr[20];
  56         char *client;
  57         struct in_addr addr;
  58         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  59                 return;
  60
  61         cp = lbuf;
  62
  63         if (qword_get(&cp, class, 20) <= 0 ||
  64             strcmp(class, "nfsd") != 0)
  65                 return;
  66
  67         if (qword_get(&cp, ipaddr, 20) <= 0)
  68                 return;
  69
  70         if (inet_aton(ipaddr, &addr)==0)
  71                 return;
  72
  73         auth_reload();
  74
  75         /* addr is a valid, interesting address, find the domain name... */
  76         client = client_compose(addr);
  77
  78
  79         qword_print(f, "nfsd");
  80         qword_print(f, ipaddr);
  81         qword_printint(f, time(0)+30*60);
  82         if (client)
  83                 qword_print(f, *client?client:"DEFAULT");
  84         qword_eol(f);
  85
  86         if (client) free(client);
  87
  88 }
  89
  90 void nfsd_fh(FILE *f)
  91 {
  92         /* request are:
  93          *  domain fsidtype fsid
  94          * interpret fsid, find export point and options, and write:
  95          *  domain fsidtype fsid expiry path
  96          */
  97         char *cp;
  98         char *dom;
  99         int fsidtype;
 100         int fsidlen;
 101         unsigned int dev, major=0, minor=0;
 102         unsigned int inode=0;
 103         unsigned int fsidnum=0;
 104         char fsid[32];
 105         struct exportent *found = NULL;
 106         nfs_export *exp;
 107         int i;
 108         int dev_missing = 0;
 109
 110         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 111                 return;
 112
 113         cp = lbuf;
 114
 115         dom = malloc(strlen(cp));
 116         if (dom == NULL)
 117                 return;
 118         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 119                 goto out;
 120         if (qword_get_int(&cp, &fsidtype) != 0)
 121                 goto out;
 122         if (fsidtype < 0 || fsidtype > 3)
 123                 goto out; /* unknown type */
 124         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 125                 goto out;
 126         switch(fsidtype) {
 127         case 0: /* 4 bytes: 2 major, 2 minor, 4 inode */
 128                 if (fsidlen != 8)
 129                         goto out;
 130                 memcpy(&dev, fsid, 4);
 131                 memcpy(&inode, fsid+4, 4);
 132                 major = ntohl(dev)>>16;
 133                 minor = ntohl(dev) & 0xFFFF;
 134                 break;
 135
 136         case 1: /* 4 bytes - fsid */
 137                 if (fsidlen != 4)
 138                         goto out;
 139                 memcpy(&fsidnum, fsid, 4);
 140                 break;
 141
 142         case 2: /* 12 bytes: 4 major, 4 minor, 4 inode
 143                  * This format is never actually used but was
 144                  * an historical accident
 145                  */
 146                 if (fsidlen != 12)
 147                         goto out;
 148                 memcpy(&dev, fsid, 4); major = ntohl(dev);
 149                 memcpy(&dev, fsid+4, 4); minor = ntohl(dev);
 150                 memcpy(&inode, fsid+8, 4);
 151                 break;
 152
 153         case 3: /* 8 bytes: 4 byte packed device number, 4 inode */
 154                 /* This is *host* endian, not net-byte-order, because
 155                  * no-one outside this host has any business interpreting it
 156                  */
 157                 if (fsidlen != 8)
 158                         goto out;
 159                 memcpy(&dev, fsid, 4);
 160                 memcpy(&inode, fsid+4, 4);
 161                 major = (dev & 0xfff00) >> 8;
 162                 minor = (dev & 0xff) | ((dev >> 12) & 0xfff00);
 163                 break;
 164
 165         }
 166
 167         auth_reload();
 168
 169         /* Now determine export point for this fsid/domain */
 170         for (i=0 ; i < MCL_MAXTYPES; i++) {
 171                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 172                         struct stat stb;
 173
 174                         if (!client_member(dom, exp->m_client->m_hostname))
 175                                 continue;
 176                         if (exp->m_export.e_mountpoint &&
 177                             !is_mountpoint(exp->m_export.e_mountpoint[0]?
 178                                            exp->m_export.e_mountpoint:
 179                                            exp->m_export.e_path))
 180                                 dev_missing ++;
 181                         if (stat(exp->m_export.e_path, &stb) != 0)
 182                                 continue;
 183                         if (fsidtype == 1 &&
 184                             ((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 185                              exp->m_export.e_fsid != fsidnum))
 186                                 continue;
 187                         if (fsidtype != 1) {
 188                                 if (stb.st_ino != inode)
 189                                         continue;
 190                                 if (major != major(stb.st_dev) ||
 191                                     minor != minor(stb.st_dev))
 192                                         continue;
 193                         }
 194                         /* It's a match !! */
 195                         if (!found)
 196                                 found = &exp->m_export;
 197                         else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 198                         {
 199                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 200                                      found->e_path, exp->m_export.e_path, dom);
 201                         }
 202                 }
 203         }
 204         if (found &&
 205             found->e_mountpoint &&
 206             !is_mountpoint(found->e_mountpoint[0]?
 207                            found->e_mountpoint:
 208                            found->e_path)) {
 209                 /* Cannot export this yet
 210                  * should log a warning, but need to rate limit
 211                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 212                    found->e_path, found->e_mountpoint);
 213                  */
 214                 /* FIXME we need to make sure we re-visit this later */
 215                 goto out;
 216         }
 217         if (!found && dev_missing) {
 218                 /* The missing dev could be what we want, so just be
 219                  * quite rather than returning stale yet
 220                  */
 221                 goto out;
 222         }
 223
 224         if (found)
 225                 cache_export_ent(dom, found);
 226
 227         qword_print(f, dom);
 228         qword_printint(f, fsidtype);
 229         qword_printhex(f, fsid, fsidlen);
 230         qword_printint(f, time(0)+30*60);
 231         if (found)
 232                 qword_print(f, found->e_path);
 233         qword_eol(f);
 234  out:
 235         free(dom);
 236         return;
 237 }
 238
 239 static int dump_to_cache(FILE *f, char *domain, char *path, struct exportent *exp)
 240 {
 241         qword_print(f, domain);
 242         qword_print(f, path);
 243         qword_printint(f, time(0)+30*60);
 244         if (exp) {
 245                 qword_printint(f, exp->e_flags);
 246                 qword_printint(f, exp->e_anonuid);
 247                 qword_printint(f, exp->e_anongid);
 248                 qword_printint(f, exp->e_fsid);
 249         }
 250         return qword_eol(f);
 251 }
 252
 253 void nfsd_export(FILE *f)
 254 {
 255         /* requests are:
 256          *  domain path
 257          * determine export options and return:
 258          *  domain path expiry flags anonuid anongid fsid
 259          */
 260
 261         char *cp;
 262         int i;
 263         char *dom, *path;
 264         nfs_export *exp, *found = NULL;
 265
 266
 267         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 268                 return;
 269
 270         cp = lbuf;
 271         dom = malloc(strlen(cp));
 272         path = malloc(strlen(cp));
 273
 274         if (!dom || !path)
 275                 goto out;
 276
 277         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 278                 goto out;
 279         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 280                 goto out;
 281
 282         auth_reload();
 283
 284         /* now find flags for this export point in this domain */
 285         for (i=0 ; i < MCL_MAXTYPES; i++) {
 286                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 287                         if (!client_member(dom, exp->m_client->m_hostname))
 288                                 continue;
 289                         if (strcmp(path, exp->m_export.e_path))
 290                                 continue;
 291                         if (!found)
 292                                 found = exp;
 293                         else {
 294                                 xlog(L_WARNING, "%s exported to both %s and %s in %s",
 295                                      path, exp->m_client->m_hostname, found->m_client->m_hostname,
 296                                      dom);
 297                         }
 298                 }
 299         }
 300
 301         if (found) {
 302                 dump_to_cache(f, dom, path, &found->m_export);
 303                 mountlist_add(dom, path);
 304         } else {
 305                 dump_to_cache(f, dom, path, NULL);
 306         }
 307  out:
 308         if (dom) free(dom);
 309         if (path) free(path);
 310 }
 311
 312
 313 struct {
 314         char *cache_name;
 315         void (*cache_handle)(FILE *f);
 316         FILE *f;
 317 } cachelist[] = {
 318         { "auth.unix.ip", auth_unix_ip},
 319         { "nfsd.export", nfsd_export},
 320         { "nfsd.fh", nfsd_fh},
 321         { NULL, NULL }
 322 };
 323
 324 void cache_open(void)
 325 {
 326         int i;
 327         for (i=0; cachelist[i].cache_name; i++ ){
 328                 char path[100];
 329                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 330                 cachelist[i].f = fopen(path, "r+");
 331         }
 332 }
 333
 334 void cache_set_fds(fd_set *fdset)
 335 {
 336         int i;
 337         for (i=0; cachelist[i].cache_name; i++) {
 338                 if (cachelist[i].f)
 339                         FD_SET(fileno(cachelist[i].f), fdset);
 340         }
 341 }
 342
 343 int cache_process_req(fd_set *readfds)
 344 {
 345         int i;
 346         int cnt = 0;
 347         for (i=0; cachelist[i].cache_name; i++) {
 348                 if (cachelist[i].f != NULL &&
 349                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 350                         cnt++;
 351                         cachelist[i].cache_handle(cachelist[i].f);
 352                         FD_CLR(fileno(cachelist[i].f), readfds);
 353                 }
 354         }
 355         return cnt;
 356 }
 357
 358
 359 /*
 360  * Give IP->domain and domain+path->options to kernel
 361  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 362  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 363  */
 364
 365 int cache_export_ent(char *domain, struct exportent *exp)
 366 {
 367         int err;
 368         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 369         if (!f)
 370                 return -1;
 371
 372         err = dump_to_cache(f, domain, exp->e_path, exp);
 373         fclose(f);
 374         mountlist_add(domain, exp->e_path);
 375         return err;
 376 }
 377
 378 int cache_export(nfs_export *exp)
 379 {
 380         int err;
 381         FILE *f;
 382
 383         if (exp->m_export.e_maptype != CLE_MAP_IDENT) {
 384                 xlog(L_ERROR, "%s: unsupported mapping; kernel supports only 'identity' (default)",
 385                     exp->m_export.m_path);
 386                 return;
 387         }
 388
 389         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 390         if (!f)
 391                 return -1;
 392
 393         qword_print(f, "nfsd");
 394         qword_print(f, inet_ntoa(exp->m_client->m_addrlist[0]));
 395         qword_printint(f, time(0)+30*60);
 396         qword_print(f, exp->m_client->m_hostname);
 397         err = qword_eol(f);
 398
 399         fclose(f);
 400
 401         err = cache_export_ent(exp->m_client->m_hostname, &exp->m_export)
 402                 || err;
 403         return err;
 404 }
 405
 406 /* Get a filehandle.
 407  * {
 408  *   echo $domain $path $length
 409  *   read filehandle <&0
 410  * } <> /proc/fs/nfsd/filehandle
 411  */
 412 struct nfs_fh_len *
 413 cache_get_filehandle(nfs_export *exp, int len, char *p)
 414 {
 415         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 416         char buf[200];
 417         char *bp = buf;
 418         int failed;
 419         static struct nfs_fh_len fh;
 420
 421         if (!f)
 422                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 423         if (!f)
 424                 return NULL;
 425
 426         qword_print(f, exp->m_client->m_hostname);
 427         qword_print(f, p);
 428         qword_printint(f, len);
 429         failed = qword_eol(f);
 430
 431         if (!failed)
 432                 failed = (fgets(buf, sizeof(buf), f) == NULL);
 433         fclose(f);
 434         if (failed)
 435                 return NULL;
 436         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 437         fh.fh_size = qword_get(&bp, (char *)fh.fh_handle, NFS3_FHSIZE);
 438         return &fh;
 439 }
 440