| #include <sys/stat.h> |
| #include <ctype.h> |
| #include <errno.h> |
| #include <limits.h> |
| #include <string.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #include "file_mode.h" |
| |
| extern char *progname; |
| |
| mode_t parse_file_mode(char *arg, mode_t mode, mode_t sumask) |
| { |
| char *clause; |
| |
| if (isdigit(*arg) && *arg < '8') { |
| unsigned long num; |
| |
| num = strtoul(arg, NULL, 8); |
| if ((num == ULONG_MAX && errno == ERANGE) || num > 07777) { |
| fprintf(stderr, "%s: invalid mode `%s'\n", progname, arg); |
| exit(255); |
| } |
| return (mode_t) num; |
| } |
| |
| while ((clause = strsep(&arg, ",")) != NULL) { |
| mode_t who = 0; |
| int action; |
| char *p = clause; |
| |
| /* |
| * Parse the who list. Optional. |
| */ |
| while (1) { |
| switch (*p++) { |
| case 'u': |
| who |= S_IRWXU | S_ISUID; |
| continue; |
| case 'g': |
| who |= S_IRWXG | S_ISGID; |
| continue; |
| case 'o': |
| who |= S_IRWXO | S_ISVTX; |
| continue; |
| case 'a': |
| who = S_IRWXU|S_IRWXG|S_IRWXO|S_ISUID|S_ISGID|S_ISVTX; |
| continue; |
| } |
| /* undo the increment above */ |
| p--; |
| break; |
| } |
| |
| if (who == 0) |
| who = (~sumask) | S_ISVTX; |
| |
| /* |
| * Parse an action list. Must be at least one action. |
| */ |
| while (*p) { |
| mode_t perm = 0; |
| |
| /* |
| * Parse the action |
| */ |
| action = *p; |
| if (action == '+' || action == '-' || action == '=') |
| p++; |
| |
| /* |
| * Parse perm |
| */ |
| while (*p) { |
| switch (*p++) { |
| case 'r': |
| perm |= S_IRUSR|S_IRGRP|S_IROTH; |
| continue; |
| case 'w': |
| perm |= S_IWUSR|S_IWGRP|S_IWOTH; |
| continue; |
| case 'x': |
| perm |= S_IXUSR|S_IXGRP|S_IXOTH; |
| continue; |
| case 'X': |
| perm |= S_ISVTX; |
| continue; |
| case 's': |
| perm |= S_ISUID|S_ISGID; |
| continue; |
| case 'u': |
| perm = mode & S_IRWXU; |
| perm |= perm >> 3 | perm >> 6; |
| if (mode & S_ISUID) |
| perm |= S_ISGID; |
| continue; |
| case 'g': |
| perm = mode & S_IRWXG; |
| perm |= perm << 3 | perm >> 3; |
| if (mode & S_ISGID) |
| perm |= S_ISUID; |
| continue; |
| case 'o': |
| perm = mode & S_IRWXO; |
| perm |= perm << 6 | perm << 3; |
| continue; |
| } |
| /* undo the increment above */ |
| p--; |
| break; |
| } |
| |
| perm &= who; |
| |
| switch (action) { |
| case '+': |
| mode |= perm; |
| continue; |
| |
| case '-': |
| mode &= ~perm; |
| continue; |
| |
| case '=': |
| mode &= ~who; |
| mode |= perm; |
| continue; |
| } |
| |
| if (!action) |
| break; |
| fprintf(stderr, "%s: invalid mode `%s'\n", progname, clause); |
| exit(255); |
| } |
| } |
| |
| return mode; |
| } |
| |