static direntry_t *direntry_from_listing (CALLER_DECL listing_t *li)
{
/* TODO: stop being lazy and have listing_init */
direntry_t *de = realloc(li, sizeof(direntry_t));
bzero(de + sizeof(listing_t), sizeof(direntry_t) - sizeof(listing_t));
de->inode = inode_next();
inode_map_add(de);
direntry_trace(
"[direntry %p inode %lu] new (" CALLER_FORMAT ") ref %u\n",
de, de->inode, CALLER_PASS 1
);
return de;
}
/*
* Read a container with the provided key
* Read all files and place them into the provided list
* Returns:
* >0 Number of read files
* -1 File error during reading
* -2 Wrong password in input
*/
int memfile_readfiles(char * filename, char * password, memfile * root)
{
char * buf ;
char * cur ;
int fd ;
int i ;
struct stat fileinfo ;
uint8_t nonce[NONCE_SZ];
uint8_t key[KEY_SZ];
uint64_t u1, u2, u3 ;
size_t header_sz ;
size_t payload_sz ;
char fname[MAXNAMESZ];
header_sz = MAGIC_SZ + 2 + NONCE_SZ + CANARI_SZ ;
/* Find out file size in bytes */
if (stat(filename, &fileinfo)!=0) {
logger("no such file: %s", filename);
return 1 ;
}
if (fileinfo.st_size < header_sz) {
logger("not a container: ", filename);
return -1 ;
}
/* Map input file */
if ((fd=open(filename, O_RDONLY))==-1) {
logger("cannot open: %s", filename);
return -1 ;
}
buf = (char*)mmap(0,
fileinfo.st_size,
PROT_READ | PROT_WRITE,
MAP_PRIVATE,
fd,
0);
close(fd);
if (buf==(char*)-1) {
logger("cannot map: %s", filename);
return -1;
}
cur = buf ;
payload_sz = fileinfo.st_size - header_sz ;
/*
* A container header is composed of:
* A magic number of MAGIC_SZ bytes
* A version number on 2 bytes: major.minor
* A nonce of size NONCE_SZ bytes
* A canari of size CANARI_SZ bytes
*/
/* Check magic number */
for (i=0 ; i<MAGIC_SZ ; i++) {
if (cur[i]!=mefs_magic[i]) {
logger("not a container: ", filename);
munmap(buf, fileinfo.st_size);
return -1 ;
}
}
cur += MAGIC_SZ ;
/* Read version number */
if (cur[0]!=mefs_version[0] ||
cur[1]!=mefs_version[1]) {
logger("unsupported version for: ", filename);
munmap(buf, fileinfo.st_size);
return -1 ;
}
cur+=2 ;
/* Copy nonce for later use */
memcpy(nonce, cur, NONCE_SZ);
cur += NONCE_SZ ;
/* Derive key from password */
derive_key(password,
strlen(password),
nonce,
NONCE_SZ,
key,
KEY_SZ,
20000);
/* Decrypt everything starting from CANARI, using nonce and key */
stream_cipher(cur,
fileinfo.st_size-(MAGIC_SZ+2+NONCE_SZ),
0,
key,
nonce);
/* Test canari has expected pattern: 0xaaaa...aa */
for (i=0 ; i<CANARI_SZ ; i++) {
if ((unsigned char)cur[i]!=0xaa) {
logger("wrong password for container: %s", filename);
munmap(buf, fileinfo.st_size);
return -2 ;
}
}
cur+=CANARI_SZ ;
/* Read files one by one */
/*
* filename is a zero-padded string of size MAXNAMESZ
* filesize on a 64 big-endian unsigned int
* ctime on a 64-big-endian unsigned int
* mtime on a 64-big-endian unsigned int
*/
i=0 ;
while (1) {
memcpy(fname, cur, MAXNAMESZ);
cur+=MAXNAMESZ;
memcpy(&u1, cur, sizeof(uint64_t));
cur+=sizeof(uint64_t);
memcpy(&u2, cur, sizeof(uint64_t));
cur+=sizeof(uint64_t);
memcpy(&u3, cur, sizeof(uint64_t));
cur+=sizeof(uint64_t);
root[i].name = strdup(fname);
root[i].sta.st_ino = inode_next();
root[i].sta.st_size = u1 ;
root[i].sta.st_ctime = u2 ;
root[i].sta.st_mtime = u3 ;
root[i].data = malloc(u1);
memcpy(root[i].data, cur, u1);
cur+=u1 ;
if ((cur-buf) >= fileinfo.st_size)
break ;
i++ ;
}
munmap(buf, fileinfo.st_size);
return 0 ;
}
