vty: Allow using hex representations in cmd numeric ranges
Ranges can now be specified in hexadecimal notation. In this case, only
hexadecimal values are accepted (prefixed with "0x").
In order to allow using a hexadecimal value as an input argument, the
command must specify the range in hexadecimal form.
This way all existing commands (decimal) won't get an hexadecimal value
unless they are further extended in the future, avoiding hard to notice
breakage due to use of stroul() without using base=0 or even worse,
using atoi() directly (which only understands decimal and provides no
error checking mechanism).
A command argument can be expanded to accept both decimal and hex in a
range by means of specifying both, example:
"mycmd (<0-255>|<0x0-0xff>)".
Related: OS#5631
Change-Id: Ia2b7fbbf5502c28374c21dbff548232680da27d4
diff --git a/src/vty/command.c b/src/vty/command.c
index d7b8026..1e76474 100644
--- a/src/vty/command.c
+++ b/src/vty/command.c
@@ -1480,19 +1480,52 @@
#error "LONG_MAX not defined!"
#endif
+/* This function is aimed at quickly guessing & filtering the numeric base a
+ * string can contain, by no means validates the entire value.
+ * Returns 16 if string follows pattern "({+,-}0x[digits])"
+ * Returns 10 if string follows pattern "({+,-}[digits])"
+ * Returns a negative value if something other is detected (error)
+*/
+static int check_base(const char *str)
+{
+ const char *ptr = str;
+ /* Skip any space */
+ while (isspace(*ptr)) ptr++;
+
+ /* Skip optional sign: */
+ if (*ptr == '+' || *ptr == '-')
+ ptr++;
+ if (*ptr == '0') {
+ ptr++;
+ if (*ptr == '\0' || isdigit(*ptr))
+ return 10;
+ if (!(*ptr == 'x' || *ptr == 'X'))
+ return -1;
+ ptr++;
+ if (isxdigit(*ptr))
+ return 16;
+ return -1;
+ }
+ return 10;
+}
+
int vty_cmd_range_match(const char *range, const char *str)
{
char *p;
char buf[DECIMAL_STRLEN_MAX_UNSIGNED + 1];
char *endptr = NULL;
+ int min_base, max_base, val_base;
if (str == NULL)
return 1;
+ if ((val_base = check_base(str)) < 0)
+ return 0;
+
if (range[1] == '-') {
signed long min = 0, max = 0, val;
- val = strtol(str, &endptr, 10);
+ val = strtol(str, &endptr, val_base);
if (*endptr != '\0')
return 0;
@@ -1504,7 +1537,9 @@
return 0;
strncpy(buf, range, p - range);
buf[p - range] = '\0';
- min = -strtol(buf, &endptr, 10);
+ if ((min_base = check_base(buf)) < 0)
+ return 0;
+ min = -strtol(buf, &endptr, min_base);
if (*endptr != '\0')
return 0;
@@ -1516,7 +1551,9 @@
return 0;
strncpy(buf, range, p - range);
buf[p - range] = '\0';
- max = strtol(buf, &endptr, 10);
+ if ((max_base = check_base(buf)) < 0)
+ return 0;
+ max = strtol(buf, &endptr, max_base);
if (*endptr != '\0')
return 0;
@@ -1528,7 +1565,7 @@
if (str[0] == '-')
return 0;
- val = strtoul(str, &endptr, 10);
+ val = strtoul(str, &endptr, val_base);
if (*endptr != '\0')
return 0;
@@ -1540,7 +1577,9 @@
return 0;
strncpy(buf, range, p - range);
buf[p - range] = '\0';
- min = strtoul(buf, &endptr, 10);
+ if ((min_base = check_base(buf)) < 0)
+ return 0;
+ min = strtoul(buf, &endptr, min_base);
if (*endptr != '\0')
return 0;
@@ -1552,7 +1591,9 @@
return 0;
strncpy(buf, range, p - range);
buf[p - range] = '\0';
- max = strtoul(buf, &endptr, 10);
+ if ((max_base = check_base(buf)) < 0)
+ return 0;
+ max = strtoul(buf, &endptr, max_base);
if (*endptr != '\0')
return 0;
@@ -1560,6 +1601,14 @@
return 0;
}
+ /* Don't allow ranges specified by min and max with different bases */
+ if (min_base != max_base)
+ return 0;
+ /* arg value passed must match the base of the range */
+ if (min_base != val_base)
+ return 0;
+
+ /* Everything's fine */
return 1;
}