blob: e226d51ad91cdb6c921fbe8fba48452e0829216f [file] [log] [blame]
/*
* This file contains helper functions for labeling support.
*
* Author : Richard Haines <richard_c_haines@btinternet.com>
*/
#include <stdlib.h>
#include <stdarg.h>
#include <ctype.h>
#include <string.h>
#include <errno.h>
#include "label_internal.h"
/*
* The read_spec_entries and read_spec_entry functions may be used to
* replace sscanf to read entries from spec files. The file and
* property services now use these.
*/
/*
* Read an entry from a spec file (e.g. file_contexts)
* entry - Buffer to allocate for the entry.
* ptr - current location of the line to be processed.
* returns - 0 on success and *entry is set to be a null
* terminated value. On Error it returns -1 and
errno will be set.
*
*/
static inline int read_spec_entry(char **entry, char **ptr, int *len, const char **errbuf)
{
*entry = NULL;
char *tmp_buf = NULL;
while (isspace(**ptr) && **ptr != '\0')
(*ptr)++;
tmp_buf = *ptr;
*len = 0;
while (!isspace(**ptr) && **ptr != '\0') {
if (!isascii(**ptr)) {
errno = EINVAL;
*errbuf = "Non-ASCII characters found";
return -1;
}
(*ptr)++;
(*len)++;
}
if (*len) {
*entry = strndup(tmp_buf, *len);
if (!*entry)
return -1;
}
return 0;
}
/*
* line_buf - Buffer containing the spec entries .
* errbuf - Double pointer used for passing back specific error messages.
* num_args - The number of spec parameter entries to process.
* ... - A 'char **spec_entry' for each parameter.
* returns - The number of items processed. On error, it returns -1 with errno
* set and may set errbuf to a specific error message.
*
* This function calls read_spec_entry() to do the actual string processing.
* As such, can return anything from that function as well.
*/
int hidden read_spec_entries(char *line_buf, const char **errbuf, int num_args, ...)
{
char **spec_entry, *buf_p;
int len, rc, items, entry_len = 0;
va_list ap;
*errbuf = NULL;
len = strlen(line_buf);
if (line_buf[len - 1] == '\n')
line_buf[len - 1] = '\0';
else
/* Handle case if line not \n terminated by bumping
* the len for the check below (as the line is NUL
* terminated by getline(3)) */
len++;
buf_p = line_buf;
while (isspace(*buf_p))
buf_p++;
/* Skip comment lines and empty lines. */
if (*buf_p == '#' || *buf_p == '\0')
return 0;
/* Process the spec file entries */
va_start(ap, num_args);
items = 0;
while (items < num_args) {
spec_entry = va_arg(ap, char **);
if (len - 1 == buf_p - line_buf) {
va_end(ap);
return items;
}
rc = read_spec_entry(spec_entry, &buf_p, &entry_len, errbuf);
if (rc < 0) {
va_end(ap);
return rc;
}
if (entry_len)
items++;
}
va_end(ap);
return items;
}