On 07/28/2015 02:50 PM, Yuli Khodorkovskiy wrote:
> Some platforms do not have %ms support in sscanf. This adds a tokenize()
> function to be used instead of sscanf. tokenize() has the ability to split on any
> delimiter. All whitespace delimiters will be squashed.
>
> Signed-off-by: Yuli Khodorkovskiy <ykhodorkovskiy@xxxxxxxxxx>
Thanks, applied.
> ---
>
> Changes from v1:
> - drop the libselinux patch altogether.
> - remove the squash_delim flag. All whitespace is now squashed and all other delimiters are not.
> - made tokenize() hidden which meant including dso.h in util.c.
> - changed len to be of type size_t
>
> libsepol/include/sepol/policydb/util.h | 6 +++
> libsepol/src/module_to_cil.c | 61 +++++++++++++++++----
> libsepol/src/util.c | 98 ++++++++++++++++++++++++++++++++++
> 3 files changed, 154 insertions(+), 11 deletions(-)
>
> diff --git a/libsepol/include/sepol/policydb/util.h b/libsepol/include/sepol/policydb/util.h
> index ef1c90d..cb97ccf 100644
> --- a/libsepol/include/sepol/policydb/util.h
> +++ b/libsepol/include/sepol/policydb/util.h
> @@ -32,5 +32,11 @@ extern int add_i_to_a(uint32_t i, uint32_t * cnt, uint32_t ** a);
> extern char *sepol_av_to_string(policydb_t * policydbp, uint32_t tclass,
> sepol_access_vector_t av);
>
> +/*
> + * The tokenize function may be used to
> + * replace sscanf
> + */
> +extern int tokenize(char *line_buf, char delim, int num_args, ...);
> +
> __END_DECLS
> #endif
> diff --git a/libsepol/src/module_to_cil.c b/libsepol/src/module_to_cil.c
> index 2d8046c..18ec6b9 100644
> --- a/libsepol/src/module_to_cil.c
> +++ b/libsepol/src/module_to_cil.c
> @@ -2859,7 +2859,7 @@ static int level_string_to_cil(char *levelstr)
> char *token = NULL;
> char *ranged = NULL;
>
> - matched = sscanf(levelstr, "%m[^:]:%ms", &sens, &cats);
> + matched = tokenize(levelstr, ':', 2, &sens, &cats);
> if (matched < 1 || matched > 2) {
> log_err("Invalid level: %s", levelstr);
> rc = -1;
> @@ -2924,7 +2924,7 @@ static int context_string_to_cil(char *contextstr)
> char *type = NULL;
> char *level = NULL;
>
> - matched = sscanf(contextstr, "%m[^:]:%m[^:]:%m[^:]:%ms", &user, &role, &type, &level);
> + matched = tokenize(contextstr, ':', 4, &user, &role, &type, &level);
> if (matched < 3 || matched > 4) {
> log_err("Invalid context: %s", contextstr);
> rc = -1;
> @@ -2965,6 +2965,7 @@ static int seusers_to_cil(struct sepol_module_package *mod_pkg)
> char *user = NULL;
> char *seuser = NULL;
> char *level = NULL;
> + char *tmp = NULL;
> int matched;
>
> if (seusers_len == 0) {
> @@ -2972,11 +2973,18 @@ static int seusers_to_cil(struct sepol_module_package *mod_pkg)
> }
>
> while ((rc = get_line(&cur, end, &line)) > 0) {
> - if (line[0] == '#') {
> + tmp = line;
> + while (isspace(*tmp)) {
> + tmp++;
> + }
> +
> + if (tmp[0] == '#' || tmp[0] == '\0') {
> + free(line);
> + line = NULL;
> continue;
> }
>
> - matched = sscanf(line, "%m[^:]:%m[^:]:%ms", &user, &seuser, &level);
> + matched = tokenize(tmp, ':', 3, &user, &seuser, &level);
>
> if (matched < 2 || matched > 3) {
> log_err("Invalid seuser line: %s", line);
> @@ -3045,28 +3053,51 @@ static int user_extra_to_cil(struct sepol_module_package *mod_pkg)
> int matched;
> char *user = NULL;
> char *prefix = NULL;
> + int prefix_len = 0;
> + char *user_str = NULL;
> + char *prefix_str = NULL;
> + char *eol = NULL;
> + char *tmp = NULL;
>
> if (userx_len == 0) {
> return 0;
> }
>
> while ((rc = get_line(&cur, end, &line)) > 0) {
> - if (line[0] == '#') {
> + tmp = line;
> + while (isspace(*tmp)) {
> + tmp++;
> + }
> +
> + if (tmp[0] == '#' || tmp[0] == '\0') {
> + free(line);
> + line = NULL;
> continue;
> }
>
> - matched = sscanf(line, "user %ms prefix %m[^;];", &user, &prefix);
> - if (matched != 2) {
> + matched = tokenize(tmp, ' ', 4, &user_str, &user, &prefix_str, &prefix);
> + if (matched != 4) {
> rc = -1;
> - log_err("Invalid file context line: %s", line);
> + log_err("Invalid user extra line: %s", line);
> goto exit;
> }
>
> + prefix_len = strlen(prefix);
> + eol = prefix + prefix_len - 1;
> + if (*eol != ';' || strcmp(user_str, "user") || strcmp(prefix_str, "prefix")) {
> + rc = -1;
> + log_err("Invalid user extra line: %s", line);
> + goto exit;
> + }
> + *eol = '\0';
> +
> cil_println(0, "(userprefix %s %s)", user, prefix);
> free(user);
> free(prefix);
> free(line);
> - user = prefix = line = NULL;
> + free(user_str);
> + free(prefix_str);
> + user = prefix = line = user_str = prefix_str = NULL;
> }
>
> if (rc == -1) {
> @@ -3096,17 +3127,25 @@ static int file_contexts_to_cil(struct sepol_module_package *mod_pkg)
> char *mode = NULL;
> char *context = NULL;
> const char *cilmode;
> + char *tmp = NULL;
>
> if (fc_len == 0) {
> return 0;
> }
>
> while ((rc = get_line(&cur, end, &line)) > 0) {
> - if (line[0] == '#') {
> + tmp = line;
> + while (isspace(*tmp)) {
> + tmp++;
> + }
> +
> + if (tmp[0] == '#' || tmp[0] == '\0') {
> + free(line);
> + line = NULL;
> continue;
> }
>
> - matched = sscanf(line, "%ms %ms %ms", ®ex, &mode, &context);
> + matched = tokenize(tmp, ' ', 3, ®ex, &mode, &context);
> if (matched < 2 || matched > 3) {
> rc = -1;
> log_err("Invalid file context line: %s", line);
> diff --git a/libsepol/src/util.c b/libsepol/src/util.c
> index a824e61..6e285d5 100644
> --- a/libsepol/src/util.c
> +++ b/libsepol/src/util.c
> @@ -19,11 +19,15 @@
> */
>
> #include <assert.h>
> +#include <ctype.h>
> +#include <stdarg.h>
> #include <stdio.h>
> #include <stdlib.h>
>
> #include <sepol/policydb/flask_types.h>
> #include <sepol/policydb/policydb.h>
> +#include <sepol/policydb/util.h>
> +#include <dso.h>
>
> struct val_to_name {
> unsigned int val;
> @@ -114,3 +118,97 @@ char *sepol_av_to_string(policydb_t * policydbp, uint32_t tclass,
>
> return avbuf;
> }
> +
> +/*
> + * The tokenize and tokenize_str functions may be used to
> + * replace sscanf to read tokens from buffers.
> + */
> +
> +/* Read a token from a buffer */
> +static inline int tokenize_str(char delim, char **str, char **ptr, size_t *len)
> +{
> + char *tmp_buf = *ptr;
> + *str = NULL;
> +
> + while (**ptr != '\0') {
> + if (isspace(delim) && isspace(**ptr)) {
> + (*ptr)++;
> + break;
> + } else if (!isspace(delim) && **ptr == delim) {
> + (*ptr)++;
> + break;
> + }
> +
> + (*ptr)++;
> + }
> +
> + *len = *ptr - tmp_buf;
> + /* If the end of the string has not been reached, this will ensure the
> + * delimiter is not included when returning the token.
> + */
> + if (**ptr != '\0') {
> + (*len)--;
> + }
> +
> + *str = strndup(tmp_buf, *len);
> + if (!*str) {
> + return -1;
> + }
> +
> + /* Squash spaces if the delimiter is a whitespace character */
> + while (**ptr != '\0' && isspace(delim) && isspace(**ptr)) {
> + (*ptr)++;
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * line_buf - Buffer containing string to tokenize.
> + * delim - The delimiter used to tokenize line_buf. A whitespace delimiter will
> + * be tokenized using isspace().
> + * num_args - The number of parameter entries to process.
> + * ... - A 'char **' for each parameter.
> + * returns - The number of items processed.
> + *
> + * This function calls tokenize_str() to do the actual string processing. The
> + * caller is responsible for calling free() on each additional argument. The
> + * function will not tokenize more than num_args and the last argument will
> + * contain the remaining content of line_buf. If the delimiter is any whitespace
> + * character, then all whitespace will be squashed.
> + */
> +int hidden tokenize(char *line_buf, char delim, int num_args, ...)
> +{
> + char **arg, *buf_p;
> + int rc, items;
> + size_t arg_len = 0;
> + va_list ap;
> +
> + buf_p = line_buf;
> +
> + /* Process the arguments */
> + va_start(ap, num_args);
> +
> + for (items = 0; items < num_args && *buf_p != '\0'; items++) {
> + arg = va_arg(ap, char **);
> +
> + /* Save the remainder of the string in arg */
> + if (items == num_args - 1) {
> + *arg = strdup(buf_p);
> + if (*arg == NULL) {
> + goto exit;
> + }
> +
> + continue;
> + }
> +
> + rc = tokenize_str(delim, arg, &buf_p, &arg_len);
> + if (rc < 0) {
> + goto exit;
> + }
> + }
> +
> +exit:
> + va_end(ap);
> + return items;
> +}
>
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