xtables: improve get_modprobe handling
In bug #455, Dmitry V. Levin proposed a more robust get_modprobe
implementation. The patch below is a version of his patch,
updated to apply to current git.
This closes bug #455.
Signed-off-by: Phil Oester <kernel@linuxace.com>
Signed-off-by: Pablo Neira Ayuso <pablo@soleta.eu>
diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 009ab91..ebc77b6 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -305,8 +305,8 @@
{
int procfile;
char *ret;
+ int count;
-#define PROCFILE_BUFSIZ 1024
procfile = open(PROC_SYS_MODPROBE, O_RDONLY);
if (procfile < 0)
return NULL;
@@ -316,19 +316,19 @@
exit(1);
}
- ret = malloc(PROCFILE_BUFSIZ);
+ ret = malloc(PATH_MAX);
if (ret) {
- memset(ret, 0, PROCFILE_BUFSIZ);
- switch (read(procfile, ret, PROCFILE_BUFSIZ)) {
- case -1: goto fail;
- case PROCFILE_BUFSIZ: goto fail; /* Partial read. Wierd */
+ count = read(procfile, ret, PATH_MAX);
+ if (count > 0 && count < PATH_MAX)
+ {
+ if (ret[count - 1] == '\n')
+ ret[count - 1] = '\0';
+ else
+ ret[count] = '\0';
+ close(procfile);
+ return ret;
}
- if (ret[strlen(ret)-1]=='\n')
- ret[strlen(ret)-1]=0;
- close(procfile);
- return ret;
}
- fail:
free(ret);
close(procfile);
return NULL;
