diff options
Diffstat (limited to 'perl-install/resize_fat/c_rewritten.xs')
| -rw-r--r-- | perl-install/resize_fat/c_rewritten.xs | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/perl-install/resize_fat/c_rewritten.xs b/perl-install/resize_fat/c_rewritten.xs new file mode 100644 index 000000000..2bca483c0 --- /dev/null +++ b/perl-install/resize_fat/c_rewritten.xs @@ -0,0 +1,265 @@ +#include "EXTERN.h" +#include "perl.h" +#include "XSUB.h" + +/* set by scan_fat, used by next */ +short *fat = NULL; +char *fat_flag_map = NULL; +unsigned int *fat_remap = NULL; +int fat_remap_size; +int type_size, nb_clusters, bad_cluster_value; + +void free_all() { +#define FREE(p) if (p) free(p), p = NULL; + FREE(fat); + FREE(fat_flag_map); + FREE(fat_remap); +#undef FREE +} + +unsigned int next(unsigned int cluster) { + short *p = fat + type_size * cluster; + if (!fat) { + free_all(); + croak("fat::next: trying to use null pointer"); + } + if (cluster >= nb_clusters + 2) { + free_all(); + croak("fat::next: cluster %d outside filesystem", cluster); + } + return type_size == 1 ? *p : *((unsigned int *) p); +} + +void set_next(unsigned int cluster, unsigned int val) { + short *p = fat + type_size * cluster; + if (!fat) { + free_all(); + croak("fat::set_next: trying to use null pointer"); + } + if (cluster >= nb_clusters + 2) { + free_all(); + croak("fat::set_next: cluster %d outside filesystem", cluster); + } + if (type_size == 1) + *p = val; + else + *((unsigned int *) p) = val; +} + +MODULE = resize_fat::c_rewritten PACKAGE = resize_fat::c_rewritten + +PROTOTYPES: DISABLE + + +void +read_fat(fd, offset, size, magic) + int fd + int offset + int size + unsigned char magic + PPCODE: +{ + fat = (short *) malloc(size); + if (!fat) { + free_all(); + croak("read_fat: not enough memory"); + } + if (lseek(fd, offset, SEEK_SET) != offset || + read(fd, fat, size) != size) { + free_all(); + croak("read_fat: reading FAT failed"); + } + if (magic != *(unsigned char *) fat) { + free_all(); + croak("read_fat: FAT has invalid signature"); + } +} + +void +write_fat(fd, size) + int fd + int size + PPCODE: +{ + if (write(fd, fat, size) != size) { + free_all(); + croak("write_fat: write failed"); + } +} + +void +free_all() + PPCODE: + free_all(); + +void +scan_fat(nb_clusters_, type_size_) + int nb_clusters_ + int type_size_ + PPCODE: +{ + unsigned int v; + int free = 0, bad = 0, used = 0; + short *p; + + type_size = type_size_; nb_clusters = nb_clusters_; + bad_cluster_value = type_size == 32 ? 0x0ffffff7 : 0xfff7; + + if (type_size % 16) { + free_all(); + croak("scan_fat: unable to handle FAT%d", type_size); + } + type_size /= 16; + + for (p = fat + 2 * type_size; p < fat + type_size * (nb_clusters + 2); p += type_size) { + v = type_size == 1 ? *p : *((unsigned int *) p); + + if (v == 0) free++; + else if (v == bad_cluster_value) bad++; + } + used = nb_clusters - free - bad; + EXTEND(SP, 3); + PUSHs(sv_2mortal(newSViv(free))); + PUSHs(sv_2mortal(newSViv(bad))); + PUSHs(sv_2mortal(newSViv(used))); +} + +unsigned int +next(unused, cluster) + void *unused + unsigned int cluster + CODE: + RETVAL = next(cluster); + OUTPUT: + RETVAL + +void +set_next(unused, cluster, val) + void *unused + unsigned int cluster + unsigned int val + CODE: + set_next(cluster, val); + +void +allocate_fat_flag(size) + int size + CODE: + fat_flag_map = calloc(size, 1); + if (!fat_flag_map) { + free_all(); + croak("allocate_fat_flag: not enough memory"); + } + +int +checkFat(cluster, type, name) + unsigned int cluster + int type + char *name + CODE: + int nb = 0; + + if (!fat_flag_map) { + free_all(); + croak("Bad FAT: trying to use null pointer"); + } + for (; cluster < bad_cluster_value; cluster = next(cluster)) { + if (cluster == 0) { + free_all(); + croak("Bad FAT: unterminated chain for %s\n", name); + } + if (cluster >= nb_clusters + 2) { + free_all(); + croak("Bad FAT: chain outside filesystem for %s\n", name); + } + if (fat_flag_map[cluster]) { + free_all(); + croak("Bad FAT: cluster %d is cross-linked for %s\n", cluster, name); + } + fat_flag_map[cluster] = type; + nb++; + } + RETVAL = nb; + OUTPUT: + RETVAL + +unsigned int +flag(cluster) + unsigned int cluster + CODE: + if (!fat_flag_map) { + free_all(); + croak("Bad FAT: trying to use null pointer"); + } + if (cluster >= nb_clusters + 2) { + free_all(); + croak("Bad FAT: going outside filesystem"); + } + RETVAL = fat_flag_map[cluster]; + OUTPUT: + RETVAL + +void +set_flag(cluster, flag) + unsigned int cluster + int flag + CODE: + if (!fat_flag_map) { + free_all(); + croak("Bad FAT: trying to use null pointer"); + } + if (cluster >= nb_clusters + 2) { + free_all(); + croak("Bad FAT: going outside filesystem"); + } + fat_flag_map[cluster] = flag; + +void +allocate_fat_remap(size) + int size + CODE: + fat_remap_size = size; + fat_remap = (unsigned int *) calloc(size, sizeof(unsigned int *)); + if (!fat_remap) { + free_all(); + croak("allocate_fat_remap: not enough memory"); + } + +unsigned int +fat_remap(cluster) + unsigned int cluster + CODE: + if (!fat_remap) { + free_all(); + croak("fat_remap: trying to use null pointer"); + } + if (cluster >= bad_cluster_value) { + RETVAL = cluster; /* special cases */ + } else { + if (cluster >= fat_remap_size) { + free_all(); + croak("fat_remap: cluster %d >= %d in fat_remap", cluster, fat_remap_size); + } + RETVAL = fat_remap[cluster]; + } + OUTPUT: + RETVAL + +void +set_fat_remap(cluster, val) + unsigned int cluster + unsigned int val + CODE: + if (!fat_remap) { + free_all(); + croak("set_fat_remap: trying to use null pointer"); + } + if (cluster >= fat_remap_size) { + free_all(); + croak("set_fat_remap: cluster %d >= %d in set_fat_remap", cluster, fat_remap_size); + } + if (val < bad_cluster_value && val >= fat_remap_size) { + free_all(); + croak("set_fat_remap: remapping cluster %d to cluster %d >= %d in set_fat_remap", cluster, val, fat_remap_size); + } + fat_remap[cluster] = val; |