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         /* addr is a valid, interesting address, find the domain name... */
  71         client = client_compose(addr);
  72
  73
  74         qword_print(f, "nfsd");
  75         qword_print(f, ipaddr);
  76         qword_printint(f, time(0)+30*60);
  77         if (client)
  78                 qword_print(f, *client?client:"DEFAULT");
  79         qword_eol(f);
  80
  81         if (client) free(client);
  82
  83 }
  84
  85 void nfsd_fh(FILE *f)
  86 {
  87         /* request are:
  88          *  domain fsidtype fsid
  89          * interpret fsid, find export point and options, and write:
  90          *  domain fsidtype fsid expiry path
  91          */
  92         char *cp;
  93         char *dom;
  94         int fsidtype;
  95         int fsidlen;
  96         unsigned int dev, major=0, minor=0;
  97         unsigned int inode=0;
  98         unsigned int fsidnum=0;
  99         char fsid[32];
 100         struct exportent *found = NULL;
 101         nfs_export *exp;
 102         int i;
 103         int dev_missing = 0;
 104
 105         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 106                 return;
 107
 108         cp = lbuf;
 109
 110         dom = malloc(strlen(cp));
 111         if (dom == NULL)
 112                 return;
 113         if (qword_get(&cp, dom, strlen(cp)) <= 0)
 114                 goto out;
 115         if (qword_get_int(&cp, &fsidtype) != 0)
 116                 goto out;
 117         if (fsidtype < 0 || fsidtype > 1)
 118                 goto out; /* unknown type */
 119         if ((fsidlen = qword_get(&cp, fsid, 32)) <= 0)
 120                 goto out;
 121         switch(fsidtype) {
 122         case 0: /* 4 bytes: 2 major, 2 minor, 4 inode */
 123                 if (fsidlen != 8)
 124                         goto out;
 125                 memcpy(&dev, fsid, 4);
 126                 memcpy(&inode, fsid+4, 4);
 127                 major = ntohl(dev)>>16;
 128                 minor = ntohl(dev) & 0xFFFF;
 129                 break;
 130
 131         case 1: /* 4 bytes - fsid */
 132                 if (fsidlen != 4)
 133                         goto out;
 134                 memcpy(&fsidnum, fsid, 4);
 135                 break;
 136         }
 137
 138         /* Now determine export point for this fsid/domain */
 139         for (i=0 ; i < MCL_MAXTYPES; i++) {
 140                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 141                         if (!client_member(dom, exp->m_client->m_hostname))
 142                                 continue;
 143                         if (fsidtype == 1 &&
 144                             ((exp->m_export.e_flags & NFSEXP_FSID) == 0 ||
 145                              exp->m_export.e_fsid != fsidnum))
 146                                 continue;
 147                         if (fsidtype == 0) {
 148                                 struct stat stb;
 149                                 if (exp->m_export.e_mountpoint &&
 150                                     !is_mountpoint(exp->m_export.e_mountpoint[0]?
 151                                                    exp->m_export.e_mountpoint:
 152                                                    exp->m_export.e_path))
 153                                         dev_missing ++;
 154                                 if (stat(exp->m_export.e_path, &stb) != 0)
 155                                         continue;
 156                                 if (stb.st_ino != inode)
 157                                         continue;
 158                                 if (major != major(stb.st_dev) ||
 159                                     minor != minor(stb.st_dev))
 160                                         continue;
 161                         }
 162                         /* It's a match !! */
 163                         if (!found)
 164                                 found = &exp->m_export;
 165                         else if (strcmp(found->e_path, exp->m_export.e_path)!= 0)
 166                         {
 167                                 xlog(L_WARNING, "%s and %s have same filehandle for %s, using first",
 168                                      found->e_path, exp->m_export.e_path, dom);
 169                         }
 170                 }
 171         }
 172         if (found &&
 173             found->e_mountpoint &&
 174             !is_mountpoint(found->e_mountpoint[0]?
 175                            found->e_mountpoint:
 176                            found->e_path)) {
 177                 /* Cannot export this yet
 178                  * should log a warning, but need to rate limit
 179                    xlog(L_WARNING, "%s not exported as %d not a mountpoint",
 180                    found->e_path, found->e_mountpoint);
 181                  */
 182                 /* FIXME we need to make sure we re-visit this later */
 183                 goto out;
 184         }
 185         if (!found && dev_missing) {
 186                 /* The missing dev could be what we want, so just be
 187                  * quite rather than returning stale yet
 188                  */
 189                 goto out;
 190         }
 191
 192         cache_export_ent(dom, found);
 193
 194         qword_print(f, dom);
 195         qword_printint(f, fsidtype);
 196         qword_printhex(f, fsid, fsidlen);
 197         qword_printint(f, time(0)+30*60);
 198         if (found)
 199                 qword_print(f, found->e_path);
 200         qword_eol(f);
 201  out:
 202         free(dom);
 203         return;
 204 }
 205
 206 void nfsd_export(FILE *f)
 207 {
 208         /* requests are:
 209          *  domain path
 210          * determine export options and return:
 211          *  domain path expiry flags anonuid anongid fsid
 212          */
 213
 214         char *cp;
 215         int i;
 216         char *dom, *path;
 217         nfs_export *exp, *found = NULL;
 218
 219
 220         if (readline(fileno(f), &lbuf, &lbuflen) != 1)
 221                 return;
 222
 223         cp = lbuf;
 224         dom = malloc(strlen(cp));
 225         path = malloc(strlen(cp));
 226
 227         if (!dom || !path)
 228                 goto out;
 229
 230         if (qword_get(&cp, dom, strlen(lbuf)) <= 0)
 231                 goto out;
 232         if (qword_get(&cp, path, strlen(lbuf)) <= 0)
 233                 goto out;
 234
 235         /* now find flags for this export point in this domain */
 236         for (i=0 ; i < MCL_MAXTYPES; i++) {
 237                 for (exp = exportlist[i]; exp; exp = exp->m_next) {
 238                         if (!client_member(dom, exp->m_client->m_hostname))
 239                                 continue;
 240                         if (strcmp(path, exp->m_export.e_path))
 241                                 continue;
 242                         if (!found)
 243                                 found = exp;
 244                         else {
 245                                 xlog(L_WARNING, "%s exported to both %s and %s in %s",
 246                                      path, exp->m_client->m_hostname, found->m_client->m_hostname,
 247                                      dom);
 248                         }
 249                 }
 250         }
 251
 252         qword_print(f, dom);
 253         qword_print(f, path);
 254         qword_printint(f, time(0)+30*60);
 255         if (found) {
 256                 qword_printint(f, found->m_export.e_flags);
 257                 qword_printint(f, found->m_export.e_anonuid);
 258                 qword_printint(f, found->m_export.e_anongid);
 259                 qword_printint(f, found->m_export.e_fsid);
 260         }
 261         qword_eol(f);
 262  out:
 263         if (dom) free(dom);
 264         if (path) free(path);
 265 }
 266
 267
 268 struct {
 269         char *cache_name;
 270         void (*cache_handle)(FILE *f);
 271         FILE *f;
 272 } cachelist[] = {
 273         { "auth.unix.ip", auth_unix_ip},
 274         { "nfsd.export", nfsd_export},
 275         { "nfsd.fh", nfsd_fh},
 276         { NULL, NULL }
 277 };
 278
 279 void cache_open(void)
 280 {
 281         int i;
 282         for (i=0; cachelist[i].cache_name; i++ ){
 283                 char path[100];
 284                 sprintf(path, "/proc/net/rpc/%s/channel", cachelist[i].cache_name);
 285                 cachelist[i].f = fopen(path, "r+");
 286         }
 287 }
 288
 289 void cache_set_fds(fd_set *fdset)
 290 {
 291         int i;
 292         for (i=0; cachelist[i].cache_name; i++) {
 293                 if (cachelist[i].f)
 294                         FD_SET(fileno(cachelist[i].f), fdset);
 295         }
 296 }
 297
 298 int cache_process_req(fd_set *readfds)
 299 {
 300         int i;
 301         int cnt = 0;
 302         for (i=0; cachelist[i].cache_name; i++) {
 303                 if (cachelist[i].f != NULL &&
 304                     FD_ISSET(fileno(cachelist[i].f), readfds)) {
 305                         cnt++;
 306                         cachelist[i].cache_handle(cachelist[i].f);
 307                 }
 308         }
 309         return cnt;
 310 }
 311
 312
 313 /*
 314  * Give IP->domain and domain+path->options to kernel
 315  * % echo nfsd $IP  $[now+30*60] $domain > /proc/net/rpc/auth.unix.ip/channel
 316  * % echo $domain $path $[now+30*60] $options $anonuid $anongid $fsid > /proc/net/rpc/nfsd.export/channel
 317  */
 318
 319 void cache_export_ent(char *domain, struct exportent *exp)
 320 {
 321
 322         FILE *f = fopen("/proc/net/rpc/nfsd.export/channel", "r+");
 323         if (!f)
 324                 return;
 325
 326         qword_print(f, domain);
 327         qword_print(f, exp->e_path);
 328         qword_printint(f, time(0)+30*60);
 329         qword_printint(f, exp->e_flags);
 330         qword_printint(f, exp->e_anonuid);
 331         qword_printint(f, exp->e_anongid);
 332         qword_printint(f, exp->e_fsid);
 333         qword_eol(f);
 334
 335         fclose(f);
 336 }
 337
 338 void cache_export(nfs_export *exp)
 339 {
 340         FILE *f;
 341
 342         f = fopen("/proc/net/rpc/auth.unix.ip/channel", "r+");
 343         if (!f)
 344                 return;
 345
 346         qword_print(f, "nfsd");
 347         qword_print(f, inet_ntoa(exp->m_client->m_addrlist[0]));
 348         qword_printint(f, time(0)+30*60);
 349         qword_print(f, exp->m_client->m_hostname);
 350         qword_eol(f);
 351
 352         fclose(f);
 353
 354         cache_export_ent(exp->m_client->m_hostname, &exp->m_export);
 355 }
 356
 357 /* Get a filehandle.
 358  * {
 359  *   echo $domain $path $length
 360  *   read filehandle <&0
 361  * } <> /proc/fs/nfs/filehandle
 362  */
 363 struct nfs_fh_len *
 364 cache_get_filehandle(nfs_export *exp, int len, char *p)
 365 {
 366         FILE *f = fopen("/proc/fs/nfs/filehandle", "r+");
 367         char buf[200];
 368         char *bp = buf;
 369         static struct nfs_fh_len fh;
 370         if (!f)
 371                 return NULL;
 372
 373         qword_print(f, exp->m_client->m_hostname);
 374         qword_print(f, p);
 375         qword_printint(f, len);
 376         qword_eol(f);
 377
 378         if (fgets(buf, sizeof(buf), f) == NULL)
 379                 return NULL;
 380         memset(fh.fh_handle, 0, sizeof(fh.fh_handle));
 381         fh.fh_size = qword_get(&bp, fh.fh_handle, NFS3_FHSIZE);
 382         return &fh;
 383 }
 384