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 #include "config.h"
  10
  11 #include <sys/types.h>
  12 #include <sys/select.h>
  13 #include <sys/stat.h>
  14 #include <time.h>
  15 #include <netinet/in.h>
  16 #include <arpa/inet.h>
  17 #include <unistd.h>
  18 #include <fcntl.h>
  19 #include <errno.h>
  20 #include <ctype.h>
  21 #include "misc.h"
  22 #include "nfslib.h"
  23 #include "exportfs.h"
  24 #include "mountd.h"
  25 #include "xmalloc.h"
  26
  27 /*
  28  * Support routines for text-based upcalls.
  29  * Fields are separated by spaces.
  30  * Fields are either mangled to quote space tab newline slosh with slosh
  31  * or a hexified with a leading \x
  32  * Record is terminated with newline.
  33  *
  34  */
  35 void cache_export_ent(char *domain, struct exportent *exp);
  36
  37
  38 char *lbuf  = NULL;
  39 int lbuflen = 0;
  40
  41 void auth_unix_ip(FILE *f)
  42 {
  43         /* requests are
  44          *  class IP-ADDR
  45          * Ignore if class != "nfsd"
  46          * Otherwise find domainname and write back:
  47          *
  48          *  "nfsd" IP-ADDR expiry domainname
  49          */
  50         char *cp;
  51         char class[20];
  52         char ipaddr[20];
  53         char *client;
  54         struct in_addr addr;
  55         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
  56                 return;
  57
  58         cp = lbuf;
  59
  60         if (qword_get(&cp, class, 20) <= 0 ||
  61             strcmp(class, "nfsd") != 0)
  62                 return;
  63
  64         if (qword_get(&cp, ipaddr, 20) <= 0)
  65                 return;
  66
  67         if (inet_aton(ipaddr, &addr)==0)
  68                 return;
  69
  70         auth_reload();
  71
  72         /* addr is a valid, interesting address, find the domain name... */
  73         client = client_compose(addr);
  74
  75
  76         qword_print(f, "nfsd");
  77         qword_print(f, ipaddr);
  78         qword_printint(f, time(0)+30*60);
  79         if (client)
  80                 qword_print(f, *client?client:"DEFAULT");
  81         qword_eol(f);
  82
  83         if (client && strcmp(ipaddr, client))
  84                 mountlist_add(ipaddr, *client?client:"DEFAULT");
  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 > 1)
 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
 143         auth_reload();
 144
 145         /* Now determine export point for this fsid/domain */
 146         for (i=0 ; i < MCL_MAXTYPES; i++) {
 147                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 148                         if (!client_member(dom, exp->m_client->m_hostname))
 149                                 continue;
 150                         if (fsidtype == 1 &&
 151                             ((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 152                              exp->m_export.e_fsid != fsidnum))
 153                                 continue;
 154                         if (fsidtype == 0) {
 155                                 struct stat stb;
 156                                 if (exp->m_export.e_mountpoint &&
 157                                     !is_mountpoint(exp->m_export.e_mountpoint[0]?
 158                                                    exp->m_export.e_mountpoint:
 159                                                    exp->m_export.e_path))
 160                                         dev_missing ++;
 161                                 if (stat(exp->m_export.e_path, &stb) != 0)
 162                                         continue;
 163                                 if (stb.st_ino != inode)
 164                                         continue;
 165                                 if (major != major(stb.st_dev) ||
 166                                     minor != minor(stb.st_dev))
 167                                         continue;
 168                         }
 169                         /* It's a match !! */
 170                         if (!found)
 171                                 found = &exp->m_export;
 172                         else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 173                         {
 174                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 175                                      found->e_path, exp->m_export.e_path, dom);
 176                         }
 177                 }
 178         }
 179         if (found &&
 180             found->e_mountpoint &&
 181             !is_mountpoint(found->e_mountpoint[0]?
 182                            found->e_mountpoint:
 183                            found->e_path)) {
 184                 /* Cannot export this yet
 185                  * should log a warning, but need to rate limit
 186                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 187                    found->e_path, found->e_mountpoint);
 188                  */
 189                 /* FIXME we need to make sure we re-visit this later */
 190                 goto out;
 191         }
 192         if (!found && dev_missing) {
 193                 /* The missing dev could be what we want, so just be
 194                  * quite rather than returning stale yet
 195                  */
 196                 goto out;
 197         }
 198
 199         if (found)
 200                 cache_export_ent(dom, found);
 201
 202         qword_print(f, dom);
 203         qword_printint(f, fsidtype);
 204         qword_printhex(f, fsid, fsidlen);
 205         qword_printint(f, time(0)+30*60);
 206         if (found)
 207                 qword_print(f, found->e_path);
 208         qword_eol(f);
 209  out:
 210         free(dom);
 211         return;
 212 }
 213
 214 void nfsd_export(FILE *f)
 215 {
 216         /* requests are:
 217          *  domain path
 218          * determine export options and return:
 219          *  domain path expiry flags anonuid anongid fsid
 220          */
 221
 222         char *cp;
 223         int i;
 224         char *dom, *path;
 225         nfs_export *exp, *found = NULL;
 226
 227
 228         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 229                 return;
 230
 231         cp = lbuf;
 232         dom = malloc(strlen(cp));
 233         path = malloc(strlen(cp));
 234
 235         if (!dom || !path)
 236                 goto out;
 237
 238         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 239                 goto out;
 240         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 241                 goto out;
 242
 243         auth_reload();
 244
 245         /* now find flags for this export point in this domain */
 246         for (i=0 ; i < MCL_MAXTYPES; i++) {
 247                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 248                         if (!client_member(dom, exp->m_client->m_hostname))
 249                                 continue;
 250                         if (strcmp(path, exp->m_export.e_path))
 251                                 continue;
 252                         if (!found)
 253                                 found = exp;
 254                         else {
 255                                 xlog(L_WARNING, "%s exported to both %s and %s in %s",
 256                                      path, exp->m_client->m_hostname, found->m_client->m_hostname,
 257                                      dom);
 258                         }
 259                 }
 260         }
 261
 262         qword_print(f, dom);
 263         qword_print(f, path);
 264         qword_printint(f, time(0)+30*60);
 265         if (found) {
 266                 qword_printint(f, found->m_export.e_flags);
 267                 qword_printint(f, found->m_export.e_anonuid);
 268                 qword_printint(f, found->m_export.e_anongid);
 269                 qword_printint(f, found->m_export.e_fsid);
 270                 mountlist_add(dom, path);
 271         }
 272         qword_eol(f);
 273  out:
 274         if (dom) free(dom);
 275         if (path) free(path);
 276 }
 277
 278
 279 struct {
 280         char *cache_name;
 281         void (*cache_handle)(FILE *f);
 282         FILE *f;
 283 } cachelist[] = {
 284         { "auth.unix.ip", auth_unix_ip},
 285         { "nfsd.export", nfsd_export},
 286         { "nfsd.fh", nfsd_fh},
 287         { NULL, NULL }
 288 };
 289
 290 void cache_open(void)
 291 {
 292         int i;
 293         for (i=0; cachelist[i].cache_name; i++ ){
 294                 char path[100];
 295                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 296                 cachelist[i].f = fopen(path, "r+");
 297         }
 298 }
 299
 300 void cache_set_fds(fd_set *fdset)
 301 {
 302         int i;
 303         for (i=0; cachelist[i].cache_name; i++) {
 304                 if (cachelist[i].f)
 305                         FD_SET(fileno(cachelist[i].f), fdset);
 306         }
 307 }
 308
 309 int cache_process_req(fd_set *readfds)
 310 {
 311         int i;
 312         int cnt = 0;
 313         for (i=0; cachelist[i].cache_name; i++) {
 314                 if (cachelist[i].f != NULL &&
 315                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 316                         cnt++;
 317                         cachelist[i].cache_handle(cachelist[i].f);
 318                         FD_CLR(fileno(cachelist[i].f), readfds);
 319                 }
 320         }
 321         return cnt;
 322 }
 323
 324
 325 /*
 326  * Give IP->domain and domain+path->options to kernel
 327  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 328  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 329  */
 330
 331 void cache_export_ent(char *domain, struct exportent *exp)
 332 {
 333
 334         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "w");
 335         if (!f)
 336                 return;
 337
 338         qword_print(f, domain);
 339         qword_print(f, exp->e_path);
 340         qword_printint(f, time(0)+30*60);
 341         qword_printint(f, exp->e_flags);
 342         qword_printint(f, exp->e_anonuid);
 343         qword_printint(f, exp->e_anongid);
 344         qword_printint(f, exp->e_fsid);
 345         qword_eol(f);
 346
 347         fclose(f);
 348
 349         mountlist_add(domain, exp->e_path);
 350 }
 351
 352 void cache_export(nfs_export *exp)
 353 {
 354         FILE *f;
 355
 356         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "w");
 357         if (!f)
 358                 return;
 359
 360         qword_print(f, "nfsd");
 361         qword_print(f, inet_ntoa(exp->m_client->m_addrlist[0]));
 362         qword_printint(f, time(0)+30*60);
 363         qword_print(f, exp->m_client->m_hostname);
 364         qword_eol(f);
 365
 366         fclose(f);
 367
 368         if (strcmp(inet_ntoa(exp->m_client->m_addrlist[0]), exp->m_client->m_hostname))
 369                 mountlist_add(inet_ntoa(exp->m_client->m_addrlist[0]), exp->m_client->m_hostname);
 370
 371         cache_export_ent(exp->m_client->m_hostname, &exp->m_export);
 372 }
 373
 374 /* Get a filehandle.
 375  * {
 376  *   echo $domain $path $length
 377  *   read filehandle <&0
 378  * } <> /proc/fs/nfsd/filehandle
 379  */
 380 struct nfs_fh_len *
 381 cache_get_filehandle(nfs_export *exp, int len, char *p)
 382 {
 383         FILE *f = fopen("/proc/fs/nfsd/filehandle", "r+");
 384         char buf[200];
 385         char *bp = buf;
 386         int failed;
 387         static struct nfs_fh_len fh;
 388
 389         if (!f)
 390                 f = fopen("/proc/fs/nfs/filehandle", "r+");
 391         if (!f)
 392                 return NULL;
 393
 394         qword_print(f, exp->m_client->m_hostname);
 395         qword_print(f, p);
 396         qword_printint(f, len);
 397         qword_eol(f);
 398
 399         failed = (fgets(buf, sizeof(buf), f) == NULL);
 400         fclose(f);
 401         if (failed)
 402                 return NULL;
 403         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 404         fh.fh_size = qword_get(&bp, fh.fh_handle, NFS3_FHSIZE);
 405         return &fh;
 406 }
 407