[patch 1/5] kvm tools: Options parser to handle hex numbers

Cyrill Gorcunov
2011-06-07T19:41:59Z

[-- Attachment #1: kvm-tools-hex-opts --]
[-- Type: text/plain, Size: 3658 bytes --]

Some kernel parameters are convenient if passed in
hex form so our options parser should handle even
such form of input.

Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
---
tools/kvm/util/parse-options.c | 102 ++++++++++++++++++++++++++++++++---------
1 file changed, 82 insertions(+), 20 deletions(-)

Index: linux-2.6.git/tools/kvm/util/parse-options.c
===================================================================
--- linux-2.6.git.orig/tools/kvm/util/parse-options.c
+++ linux-2.6.git/tools/kvm/util/parse-options.c
@@ -39,6 +39,84 @@ static int get_arg(struct parse_opt_ctx_
return 0;
}

+#define numvalue(c) \
+ ((c) >= 'a' ? (c) - 'a' + 10 : \
+ (c) >= 'A' ? (c) - 'A' + 10 : (c) - '0')
+
+static u64 readhex(const char *str, bool *error)
+{
+ char *pos = strchr(str, 'x') + 1;
+ u64 res = 0;
+
+ while (*pos) {
+ unsigned int v = numvalue(*pos);
+ if (v > 16) {
+ *error = true;
+ return 0;
+ }
+
+ res = (res * 16) + v;
+ pos++;
+ }
+
+ *error = false;
+ return res;
+}
+
+static int readnum(const struct option *opt, int flags,
+ const char *str, char **end)
+{
+ if (strchr(str, 'x')) {
+ bool error;
+ u64 value;
+
+ value = readhex(str, &error);
+ if (error)
+ goto enotnum;
+
+ switch (opt->type) {
+ case OPTION_INTEGER:
+ *(int *)opt->value = value;
+ break;
+ case OPTION_UINTEGER:
+ *(unsigned int *)opt->value = value;
+ break;
+ case OPTION_LONG:
+ *(long *)opt->value = value;
+ break;
+ case OPTION_U64:
+ *(u64 *)opt->value = value;
+ break;
+ default:
+ goto invcall;
+ }
+ } else {
+ switch (opt->type) {
+ case OPTION_INTEGER:
+ *(int *)opt->value = strtol(str, end, 10);
+ break;
+ case OPTION_UINTEGER:
+ *(unsigned int *)opt->value = strtol(str, end, 10);
+ break;
+ case OPTION_LONG:
+ *(long *)opt->value = strtol(str, end, 10);
+ break;
+ case OPTION_U64:
+ *(u64 *)opt->value = strtoull(str, end, 10);
+ break;
+ default:
+ goto invcall;
+ }
+ }
+
+ return 0;
+
+enotnum:
+ return opterror(opt, "expects a numerical value", flags);
+invcall:
+ return opterror(opt, "invalid numeric conversion", flags);
+}
+
static int get_value(struct parse_opt_ctx_t *p,
const struct option *opt, int flags)
{
@@ -131,11 +209,7 @@ static int get_value(struct parse_opt_ct
}
if (get_arg(p, opt, flags, &arg))
return -1;
- *(int *)opt->value = strtol(arg, (char **)&s, 10);
- if (*s)
- return opterror(opt, "expects a numerical value",
- flags);
- return 0;
+ return readnum(opt, flags, arg, (char **)&s);

case OPTION_UINTEGER:
if (unset) {
@@ -148,11 +222,7 @@ static int get_value(struct parse_opt_ct
}
if (get_arg(p, opt, flags, &arg))
return -1;
- *(unsigned int *)opt->value = strtol(arg, (char **)&s, 10);
- if (*s)
- return opterror(opt,
- "expects a numerical value", flags);
- return 0;
+ return readnum(opt, flags, arg, (char **)&s);

case OPTION_LONG:
if (unset) {
@@ -165,11 +235,7 @@ static int get_value(struct parse_opt_ct
}
if (get_arg(p, opt, flags, &arg))
return -1;
- *(long *)opt->value = strtol(arg, (char **)&s, 10);
- if (*s)
- return opterror(opt,
- "expects a numerical value", flags);
- return 0;
+ return readnum(opt, flags, arg, (char **)&s);

case OPTION_U64:
if (unset) {
@@ -182,11 +248,7 @@ static int get_value(struct parse_opt_ct
}
if (get_arg(p, opt, flags, &arg))
return -1;
- *(u64 *)opt->value = strtoull(arg, (char **)&s, 10);
- if (*s)
- return opterror(opt,
- "expects a numerical value", flags);
- return 0;
+ return readnum(opt, flags, arg, (char **)&s);