nbdsrv.c

   1 #include "config.h"
   2 #include "nbd-debug.h"
   3
   4 #include <nbdsrv.h>
   5
   6 #include <assert.h>
   7 #include <ctype.h>
   8 #include <netdb.h>
   9 #include <stdlib.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <syslog.h>
  13 #include <unistd.h>
  14 #include <pthread.h>
  15
  16 #include <sys/stat.h>
  17 #include <sys/types.h>
  18 #include <sys/socket.h>
  19 #include <treefiles.h>
  20 #include "backend.h"
  21 #ifdef HAVE_SYS_IOCTL_H
  22 #include <sys/ioctl.h>
  23 #endif
  24 #ifdef HAVE_SYS_MOUNT_H
  25 #include <sys/mount.h>
  26 #endif
  27
  28 #define LINELEN 256       /**< Size of static buffer used to read the
  29                                authorization file (yuck) */
  30 #include <cliserv.h>
  31
  32 bool address_matches(const char* mask, const struct sockaddr* addr, GError** err) {
  33         struct addrinfo *res, *aitmp, hints;
  34         char *masksep;
  35         char privmask[strlen(mask)+1];
  36         int masklen;
  37         int addrlen = addr->sa_family == AF_INET ? 4 : 16;
  38 #define IPV4_MAP_PREFIX 12
  39         uint8_t ipv4_mapped[IPV4_MAP_PREFIX+4] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  40                 255, 255, 0, 0, 0, 0};
  41
  42         strcpy(privmask, mask);
  43
  44         memset(&hints, 0, sizeof(hints));
  45         hints.ai_family = AF_UNSPEC;
  46         hints.ai_flags = AI_NUMERICHOST;
  47
  48         if((masksep = strchr(privmask, '/'))) {
  49                 *masksep = '\0';
  50                 masklen = strtol(++masksep, NULL, 10);
  51         } else {
  52                 masklen = addrlen * 8;
  53         }
  54
  55         if (masklen > addrlen * 8 || masklen < 0) {
  56                 g_set_error(err, NBDS_ERR, NBDS_ERR_CFILE_VALUE_INVALID, "could not parse netmask line: invalid mask length");
  57                 return false;
  58         }
  59
  60         int e;
  61         if((e = getaddrinfo(privmask, NULL, &hints, &res))) {
  62                 g_set_error(err, NBDS_ERR, NBDS_ERR_GAI, "could not parse netmask line: %s", gai_strerror(e));
  63                 return false;
  64         }
  65         aitmp = res;
  66         while(res) {
  67                 assert(addr->sa_family == AF_INET || addr->sa_family == AF_INET6);
  68                 const uint8_t* byte_s;
  69                 uint8_t* byte_t;
  70                 uint8_t mask = 0;
  71                 int len_left = masklen;
  72                 if(res->ai_family == addr->sa_family) {
  73                         /* Both addresses are the same address family so do a simple comparison */
  74                         switch(addr->sa_family) {
  75                         case AF_INET:
  76                                 byte_s = (const uint8_t*)(&(((struct sockaddr_in*)addr)->sin_addr));
  77                                 byte_t = (uint8_t*)(&(((struct sockaddr_in*)(res->ai_addr))->sin_addr));
  78                                 break;
  79                         case AF_INET6:
  80                                 byte_s = (const uint8_t*)(&(((struct sockaddr_in6*)addr)->sin6_addr));
  81                                 byte_t = (uint8_t*)(&(((struct sockaddr_in6*)(res->ai_addr))->sin6_addr));
  82                                 break;
  83                         }
  84                 } else {
  85                         /* Addresses are different families, compare IPv4-mapped IPv6 address */
  86                         switch(addr->sa_family) {
  87                         case AF_INET:
  88                                 /* Map client address to IPv6 for comparison */
  89                                 memcpy(&ipv4_mapped[IPV4_MAP_PREFIX], &(((struct sockaddr_in*)addr)->sin_addr), 4);
  90                                 byte_s = (const uint8_t*)&ipv4_mapped;
  91                                 byte_t = (uint8_t*)(&(((struct sockaddr_in6*)(res->ai_addr))->sin6_addr));
  92                                 len_left += IPV4_MAP_PREFIX * 8;
  93                                 break;
  94                         case AF_INET6:
  95                                 byte_s = (const uint8_t*)(&(((struct sockaddr_in6*)addr)->sin6_addr));
  96                                 /* Map res to IPv6 for comparison */
  97                                 memcpy(&ipv4_mapped[IPV4_MAP_PREFIX], &(((struct sockaddr_in*)(res->ai_addr))->sin_addr), 4);
  98                                 byte_t = &ipv4_mapped[0];
  99                                 len_left += IPV4_MAP_PREFIX * 8;
 100                                 break;
 101                         }
 102                 }
 103                 while(len_left >= 8) {
 104                         if(*byte_s != *byte_t) {
 105                                 goto next;
 106                         }
 107                         byte_s++; byte_t++;
 108                         len_left -= 8;
 109                 }
 110                 if(len_left) {
 111                         mask = getmaskbyte(len_left);
 112                         if((*byte_s & mask) != (*byte_t & mask)) {
 113                                 goto  next;
 114                         }
 115                 }
 116                 freeaddrinfo(aitmp);
 117                 return true;
 118         next:
 119                 res = res->ai_next;
 120         }
 121         freeaddrinfo(aitmp);
 122         return false;
 123 }
 124
 125 uint8_t getmaskbyte(int masklen) {
 126         if(masklen >= 8) {
 127                 return 0xFF;
 128         }
 129         uint8_t retval = 0;
 130         for(int i = 7; i + masklen > 7; i--) {
 131                 retval |= 1 << i;
 132         }
 133
 134         return retval;
 135 }
 136
 137 int authorized_client(CLIENT *opts) {
 138         FILE *f ;
 139         char line[LINELEN];
 140
 141         if (opts->server->authname == NULL) {
 142                 msg(LOG_INFO, "No authorization file, granting access.");
 143                 return 1;
 144         }
 145
 146         if ((f=fopen(opts->server->authname,"r"))==NULL) {
 147                 msg(LOG_INFO, "Can't open authorization file %s (%s).",
 148                     opts->server->authname, strerror(errno));
 149                 return 1 ;
 150         }
 151
 152         while (fgets(line,LINELEN,f)!=NULL) {
 153                 char* pos;
 154                 char* endpos;
 155                 /* Drop comments */
 156                 if((pos = strchr(line, '#'))) {
 157                         *pos = '\0';
 158                 }
 159                 /* Skip whitespace */
 160                 pos = line;
 161                 while((*pos) && isspace(*pos)) {
 162                         pos++;
 163                 }
 164                 /* Skip content-free lines */
 165                 if(!(*pos)) {
 166                         continue;
 167                 }
 168                 /* Trim trailing whitespace */
 169                 endpos = pos;
 170                 while ((*endpos) && !isspace(*endpos))
 171                         endpos++;
 172                 *endpos = '\0';
 173                 if(address_matches(pos, (struct sockaddr*)&opts->clientaddr, NULL)) {
 174                         fclose(f);
 175                         return 1;
 176                 }
 177         }
 178         fclose(f);
 179         return 0;
 180 }
 181
 182 /**
 183  * duplicate server
 184  * @param s the old server we want to duplicate
 185  * @return new duplicated server
 186  **/
 187 SERVER* dup_serve(const SERVER *const s) {
 188         SERVER *serve = NULL;
 189
 190         serve=g_new0(SERVER, 1);
 191         if(serve == NULL)
 192                 return NULL;
 193
 194         if(s->exportname)
 195                 serve->exportname = g_strdup(s->exportname);
 196
 197         serve->expected_size = s->expected_size;
 198
 199         if(s->listenaddr)
 200                 serve->listenaddr = g_strdup(s->listenaddr);
 201
 202         if(s->authname)
 203                 serve->authname = g_strdup(s->authname);
 204
 205         serve->flags = s->flags;
 206         serve->virtstyle = s->virtstyle;
 207         serve->cidrlen = s->cidrlen;
 208
 209         if(s->prerun)
 210                 serve->prerun = g_strdup(s->prerun);
 211
 212         if(s->postrun)
 213                 serve->postrun = g_strdup(s->postrun);
 214
 215         if(s->transactionlog)
 216                 serve->transactionlog = g_strdup(s->transactionlog);
 217
 218         if(s->servename)
 219                 serve->servename = g_strdup(s->servename);
 220
 221         if(s->cowdir)
 222                 serve->cowdir = g_strdup(s->cowdir);
 223
 224         serve->max_connections = s->max_connections;
 225
 226         return serve;
 227 }
 228
 229 uint64_t size_autodetect(int fhandle) {
 230         off_t es;
 231         u64 bytes __attribute__((unused));
 232         struct stat stat_buf;
 233         int error;
 234
 235 #ifdef HAVE_SYS_MOUNT_H
 236 #ifdef HAVE_SYS_IOCTL_H
 237 #ifdef BLKGETSIZE64
 238         DEBUG("looking for export size with ioctl BLKGETSIZE64\n");
 239         if (!ioctl(fhandle, BLKGETSIZE64, &bytes) && bytes) {
 240                 return bytes;
 241         }
 242 #endif /* BLKGETSIZE64 */
 243 #endif /* HAVE_SYS_IOCTL_H */
 244 #endif /* HAVE_SYS_MOUNT_H */
 245
 246         DEBUG("looking for fhandle size with fstat\n");
 247         stat_buf.st_size = 0;
 248         error = fstat(fhandle, &stat_buf);
 249         if (!error) {
 250                 /* always believe stat if a regular file as it might really
 251                  * be zero length */
 252                 if (S_ISREG(stat_buf.st_mode) || (stat_buf.st_size > 0))
 253                         return (uint64_t)stat_buf.st_size;
 254         } else {
 255                 DEBUG("fstat failed: %s", strerror(errno));
 256         }
 257
 258         DEBUG("looking for fhandle size with lseek SEEK_END\n");
 259         es = lseek(fhandle, (off_t)0, SEEK_END);
 260         if (es > ((off_t)0)) {
 261                 return (uint64_t)es;
 262         } else {
 263                 DEBUG("lseek failed: %d", errno==EBADF?1:(errno==ESPIPE?2:(errno==EINVAL?3:4)));
 264         }
 265
 266         DEBUG("Could not find size of exported block device: %s", strerror(errno));
 267         return UINT64_MAX;
 268 }
 269
 270 int exptrim(struct nbd_request* req, CLIENT* client) {
 271         /* Caller did range checking */
 272         assert(!(client->server->flags & F_READONLY));
 273         assert(req->from + req->len <= client->exportsize);
 274         /* For copy-on-write, we should trim on the diff file. Not yet
 275          * implemented. */
 276         if(client->server->flags & F_COPYONWRITE) {
 277                 DEBUG("TRIM not supported yet on copy-on-write exports");
 278                 return 0;
 279         }
 280         if (client->server->flags & F_TREEFILES) {
 281                 /* start address of first block to be trimmed */
 282                 off_t min = ( ( req->from + TREEPAGESIZE - 1 ) / TREEPAGESIZE) * TREEPAGESIZE;
 283                 /* start address of first block NOT to be trimmed */
 284                 off_t max = ( ( req->from + req->len ) / TREEPAGESIZE) * TREEPAGESIZE;
 285                 while (min<max) {
 286                         delete_treefile(client->exportname,client->exportsize,min);
 287                         min+=TREEPAGESIZE;
 288                 }
 289                 DEBUG("Performed TRIM request on TREE structure from %llu to %llu", (unsigned long long) req->from, (unsigned long long) req->len);
 290                 return 0;
 291         }
 292         FILE_INFO cur = g_array_index(client->export, FILE_INFO, 0);
 293         FILE_INFO next;
 294         int i = 1;
 295         do {
 296                 if(i<client->export->len) {
 297                         next = g_array_index(client->export, FILE_INFO, i);
 298                 } else {
 299                         next.fhandle = -1;
 300                         next.startoff = client->exportsize;
 301                 }
 302                 if(cur.startoff <= req->from && next.startoff - cur.startoff >= req->len) {
 303                         off_t reqoff = req->from - cur.startoff;
 304                         off_t curlen = next.startoff - reqoff;
 305                         off_t reqlen = curlen - reqoff > req->len ? req->len : curlen - reqoff;
 306                         punch_hole(cur.fhandle, reqoff, reqlen);
 307                 }
 308                 cur = next;
 309                 i++;
 310         } while(i < client->export->len && cur.startoff < (req->from + req->len));
 311         DEBUG("Performed TRIM request from %llu to %llu", (unsigned long long) req->from, (unsigned long long) req->len);
 312         return 0;
 313 }
 314
 315 pthread_mutex_t cntmutex = PTHREAD_MUTEX_INITIALIZER;
 316
 317 SERVER* serve_inc_ref(SERVER *s) {
 318         pthread_mutex_lock(&cntmutex);
 319         s->refcnt++;
 320         pthread_mutex_unlock(&cntmutex);
 321         return s;
 322 }
 323
 324 SERVER* serve_dec_ref(SERVER *s) {
 325         pthread_mutex_lock(&cntmutex);
 326         if(--(s->refcnt) == 0) {
 327                 g_free(s);
 328                 s = NULL;
 329         }
 330         pthread_mutex_unlock(&cntmutex);
 331         return s;
 332 }
 333
 334 void serve_clear_element(SERVER **server) {
 335         serve_dec_ref(*server);
 336 }