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