| 0,0 → 1,110 |
|---|
| /* This file contains a few general purpose utility routines. */ |
| |
| /* Methods: |
| * fetch_name: go get a path name from user space |
| * no_sys: reject a system call that FS does not handle |
| * conv2: does byte swapping on a 16-bit int |
| * conv4: does byte swapping on a 32-bit long |
| * fs_strncmp: same like strncmp |
| */ |
| |
| |
| #include <unistd.h> |
| #include "fs.h" |
| #include "block.h" |
| #include "file.h" |
| #include "fproc.h" |
| #include "inode.h" |
| |
| |
| int fetch_name(char* path, int len) |
| { |
| |
| /* Go get path and put it in 'user_path' */ |
| |
| register char *rpu, *rpm; |
| |
| /* Check name length for validity */ |
| if (len <= 0) { |
| err_code = FS_EINVAL; |
| return FS_EGENERIC; |
| } |
| |
| if (len > PATH_MAX) { |
| err_code = FS_ENAMETOOLONG; |
| return FS_EGENERIC; |
| } |
| |
| rpu = &user_path[0]; |
| rpm = path; |
| do { *rpu++ = *rpm++; |
| } while (--len); |
| |
| return OK; |
| } |
| |
| int no_sys() |
| { |
| |
| /* Somebody has used an illegal system call number */ |
| |
| print_console("FS_NOSYS called, illegal system call number!\n"); |
| |
| return FS_EINVAL; |
| } |
| |
| unsigned conv2(int norm, int w) |
| { |
| |
| /* Possibly swap a 16-bit word between 8086 and 68000 byte order. */ |
| |
| if (norm) /* TRUE if no swap, FALSE for byte swap */ |
| return((unsigned) w & 0xFFFF); |
| |
| return(((w&BYTE) << 8) | ( (w>>8) & BYTE)); |
| } |
| |
| long conv4(int norm, long x) |
| { |
| |
| /* Possibly swap a 32-bit long between 8086 and 68000 byte order. */ |
| |
| unsigned lo, hi; |
| long l; |
| |
| if (norm) /* byte order was already ok */ |
| return(x); |
| |
| lo = conv2(FALSE, (int) x & 0xFFFF); /* low-order half, byte swapped */ |
| hi = conv2(FALSE, (int) (x>>16) & 0xFFFF); /* high-order half, swapped */ |
| l = ((long) lo <<16) | hi; |
| |
| return l; |
| } |
| |
| int fs_strncmp(const char *src, const char *dst, size_t len) |
| { |
| |
| int i, src_len, dst_len; |
| |
| if (src == NULL) { |
| if (dst == NULL) |
| return 0; |
| return -1; |
| } |
| |
| if (dst == NULL) |
| return 1; |
| |
| src_len = strlen(src); |
| dst_len = strlen(dst); |
| |
| for (i = 0; i < len && i < src_len && i < dst_len; i++) { |
| if (src[i] > dst[i]) |
| return 1; |
| if (src[i] < dst[i]) |
| return -1; |
| } |
| |
| return 0; |
| } |