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