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