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#include "lar.h"
int lar_read32( int fd, uint32_t *val )
{
uint8_t buffer[5];
if( read(fd, buffer, 4) < 4 )
LAR_DIE("Unexpected EOF while reading data");
buffer[4] = 0;
*val = ntohl(*((uint32_t *) buffer));
return 0;
}
int lar_read16( int fd, uint16_t *val )
{
uint8_t buffer[3];
if( read(fd, buffer, 2) < 2 )
LAR_DIE("Unexpected EOF while reading data");
buffer[2] = 0;
*val = ntohs(*((uint16_t *) buffer));
return 0;
}
lar_index * lar_get_index( lar_archive *ar )
{
uint32_t i;
uint32_t idx_offset;
uint32_t idx_length;
lar_index *idx_map, *idx_ptr;
if( lseek(ar->fd, -(sizeof(idx_offset)), SEEK_END) == -1 )
LAR_DIE("Unable to seek to end of archive");
lar_read32(ar->fd, &idx_offset);
idx_length = ( ar->length - idx_offset - sizeof(idx_offset) );
if( lseek(ar->fd, idx_offset, SEEK_SET) == -1 )
LAR_DIE("Unable to seek to archive index");
idx_map = NULL;
for( i = 0; i < idx_length; \
i += (sizeof(lar_index) - sizeof(char))
) {
idx_ptr = (lar_index *)malloc(sizeof(lar_index));
lar_read32(ar->fd, &idx_ptr->noffset);
lar_read32(ar->fd, &idx_ptr->nlength);
lar_read32(ar->fd, &idx_ptr->foffset);
lar_read32(ar->fd, &idx_ptr->flength);
lar_read16(ar->fd, &idx_ptr->type);
lar_read16(ar->fd, &idx_ptr->flags);
idx_ptr->next = idx_map;
idx_map = idx_ptr;
}
return idx_map;
}
uint32_t lar_get_filename( lar_archive *ar,
lar_index *idx_ptr, char *filename
) {
if( idx_ptr->nlength >= LAR_FNAME_BUFFER )
LAR_DIE("Filename exceeds maximum allowed length");
if( lseek(ar->fd, idx_ptr->noffset, SEEK_SET) == -1 )
LAR_DIE("Unexpected EOF while seeking filename");
if( read(ar->fd, filename, idx_ptr->nlength) < idx_ptr->nlength )
LAR_DIE("Unexpected EOF while reading filename");
filename[idx_ptr->nlength] = 0;
return idx_ptr->nlength;
}
lar_member * lar_open_member( lar_archive *ar, const char *name )
{
lar_index *idx_ptr = ar->index;
lar_member *member;
char memberfile[LAR_FNAME_BUFFER];
char *memberdata;
size_t pgsz = getpagesize();
while(idx_ptr)
{
lar_get_filename(ar, idx_ptr, memberfile);
if( !strncmp(memberfile, name, idx_ptr->nlength) )
{
memberdata = mmap(
0, idx_ptr->flength + ( idx_ptr->foffset % pgsz ),
PROT_READ, MAP_PRIVATE, ar->fd,
idx_ptr->foffset - ( idx_ptr->foffset % pgsz )
);
if( memberdata == MAP_FAILED )
LAR_DIE("Failed to mmap() member data");
member = (lar_member *)malloc(sizeof(lar_member));
member->type = idx_ptr->type;
member->flags = idx_ptr->flags;
member->length = idx_ptr->flength;
member->data = &memberdata[idx_ptr->foffset % pgsz];
member->mmap = memberdata;
member->mlen = idx_ptr->flength + ( idx_ptr->foffset % pgsz );
return member;
}
idx_ptr = idx_ptr->next;
}
return NULL;
}
int lar_close_member( lar_member *member )
{
int stat = munmap(member->mmap, member->mlen);
free(member);
return stat;
}
lar_archive * lar_open( const char *filename )
{
int fd;
struct stat as;
lar_archive *ar;
if( stat(filename, &as) == -1 )
return NULL;
if( !(as.st_mode & S_IFREG) )
return NULL;
if( (fd = open(filename, O_RDONLY)) != -1 )
{
ar = (lar_archive *)malloc(sizeof(lar_archive));
ar->fd = fd;
ar->length = as.st_size;
ar->index = lar_get_index(ar);
strncpy(ar->filename, filename, sizeof(ar->filename));
return ar;
}
return NULL;
}
int lar_close( lar_archive *ar )
{
lar_index *idx_head;
lar_index *idx_next;
close(ar->fd);
idx_head = ar->index;
do {
idx_next = idx_head->next;
free(idx_head);
} while( (idx_head = idx_next) != NULL );
free(ar);
return 0;
}
lar_archive * lar_find_archive( const char *package )
{
int seg = 1;
int i, j, len;
struct stat s;
LAR_FNAME(buffer);
for( len = 0; package[len] != '\0'; len++ )
{
if( len >= (sizeof(buffer) - 5) )
LAR_DIE("Package name exceeds maximum allowed length");
if( package[len] == '.' ) seg++;
}
while( seg > 0 )
{
for( i = 0, j = 1; (i < len) && (j <= seg); i++ )
{
if( package[i] == '.' ) {
if( j < seg ) j++; else break;
}
buffer[i] = ( package[i] == '.' ) ? LAR_DIRSEP : package[i];
}
buffer[i+0] = '.'; buffer[i+1] = 'l'; buffer[i+2] = 'a';
buffer[i+3] = 'r'; buffer[i+4] = '\0';
if( (stat(buffer, &s) > -1) && (s.st_mode & S_IFREG) )
return lar_open(buffer);
seg--;
}
return NULL;
}
lar_member * lar_find_member( lar_archive *ar, const char *package )
{
int len;
LAR_FNAME(buffer);
for( len = 0; package[len] != '\0'; len++ )
{
if( len >= (sizeof(buffer) - 5) )
LAR_DIE("Package name exceeds maximum allowed length");
buffer[len] = ( package[len] == '.' ) ? '/' : package[len];
}
buffer[len+0] = '.'; buffer[len+1] = 'l'; buffer[len+2] = 'u';
buffer[len+3] = 'a'; buffer[len+4] = '\0';
return lar_open_member(ar, buffer);
}
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