[iptables,2/3] xtables: Introduce and use common function to parse val[/mask] arguments

Message ID 1519902192-17312-3-git-send-email-serhe.popovych@gmail.com
State Accepted
Delegated to: Pablo Neira
Headers show
Series
  • iptables: Unify val[/mask] parsing and printing routines
Related show

Commit Message

Serhey Popovych March 1, 2018, 11:03 a.m.
There are a couple of places in both core and extensions where arguments
in the form of val[/mask] is parsed (see XTTYPE_MARKMASK32).

In some cases symbolic name might be used which is mapped in code to
numeric value.

Introduce common function to handle both cases where value given is
either val[/mask] or symbolic name.

Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com>
---
 extensions/libipt_realm.c   |   29 +++++++-----------------
 extensions/libxt_devgroup.c |   35 +++++------------------------
 include/xtables.h           |   11 +++++++++
 libxtables/xtables.c        |   52 +++++++++++++++++++++++++++++++++++++++++++
 libxtables/xtoptions.c      |   22 +-----------------
 5 files changed, 77 insertions(+), 72 deletions(-)

Comments

Florian Westphal April 27, 2018, 9:07 p.m. | #1
Serhey Popovych <serhe.popovych@gmail.com> wrote:
> There are a couple of places in both core and extensions where arguments
> in the form of val[/mask] is parsed (see XTTYPE_MARKMASK32).
> 
> In some cases symbolic name might be used which is mapped in code to
> numeric value.
> 
> Introduce common function to handle both cases where value given is
> either val[/mask] or symbolic name.

Applied, thanks.
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Patch

diff --git a/extensions/libipt_realm.c b/extensions/libipt_realm.c
index 7500910..545b258 100644
--- a/extensions/libipt_realm.c
+++ b/extensions/libipt_realm.c
@@ -34,30 +34,17 @@  static struct xtables_lmap *realms;
 
 static void realm_parse(struct xt_option_call *cb)
 {
-	struct xt_realm_info *realminfo = cb->data;
-	int id;
-	char *end;
+	struct xt_realm_info *ri = cb->data;
+	unsigned int id, mask;
 
 	xtables_option_parse(cb);
-	realminfo->id = strtoul(cb->arg, &end, 0);
-	if (end != cb->arg && (*end == '/' || *end == '\0')) {
-		if (*end == '/')
-			realminfo->mask = strtoul(end+1, &end, 0);
-		else
-			realminfo->mask = 0xffffffff;
-		if (*end != '\0' || end == cb->arg)
-			xtables_error(PARAMETER_PROBLEM,
-				   "Bad realm value \"%s\"", cb->arg);
-	} else {
-		id = xtables_lmap_name2id(realms, cb->arg);
-		if (id == -1)
-			xtables_error(PARAMETER_PROBLEM,
-				   "Realm \"%s\" not found", cb->arg);
-		realminfo->id = id;
-		realminfo->mask = 0xffffffff;
-	}
+	xtables_parse_val_mask(cb, &id, &mask, realms);
+
+	ri->id = id;
+	ri->mask = mask;
+
 	if (cb->invert)
-		realminfo->invert = 1;
+		ri->invert = 1;
 }
 
 static void
diff --git a/extensions/libxt_devgroup.c b/extensions/libxt_devgroup.c
index f1352c4..99a4d50 100644
--- a/extensions/libxt_devgroup.c
+++ b/extensions/libxt_devgroup.c
@@ -35,49 +35,24 @@  static const char f_devgroups[] = "/etc/iproute2/group";
 /* array of devgroups from f_devgroups[] */
 static struct xtables_lmap *devgroups;
 
-static void devgroup_parse_groupspec(const char *arg, unsigned int *group,
-				     unsigned int *mask)
-{
-	char *end;
-	bool ok;
-
-	ok = xtables_strtoui(arg, &end, group, 0, UINT32_MAX);
-	if (ok && (*end == '/' || *end == '\0')) {
-		if (*end == '/')
-			ok = xtables_strtoui(end + 1, NULL, mask,
-			                     0, UINT32_MAX);
-		else
-			*mask = ~0U;
-		if (!ok)
-			xtables_error(PARAMETER_PROBLEM,
-				      "Bad group value \"%s\"", arg);
-	} else {
-		*group = xtables_lmap_name2id(devgroups, arg);
-		if (*group == -1)
-			xtables_error(PARAMETER_PROBLEM,
-				      "Device group \"%s\" not found", arg);
-		*mask = ~0U;
-	}
-}
-
 static void devgroup_parse(struct xt_option_call *cb)
 {
 	struct xt_devgroup_info *info = cb->data;
-	unsigned int id, mask;
+	unsigned int group, mask;
 
 	xtables_option_parse(cb);
+	xtables_parse_val_mask(cb, &group, &mask, devgroups);
+
 	switch (cb->entry->id) {
 	case O_SRC_GROUP:
-		devgroup_parse_groupspec(cb->arg, &id, &mask);
-		info->src_group = id;
+		info->src_group = group;
 		info->src_mask  = mask;
 		info->flags |= XT_DEVGROUP_MATCH_SRC;
 		if (cb->invert)
 			info->flags |= XT_DEVGROUP_INVERT_SRC;
 		break;
 	case O_DST_GROUP:
-		devgroup_parse_groupspec(cb->arg, &id, &mask);
-		info->dst_group = id;
+		info->dst_group = group;
 		info->dst_mask  = mask;
 		info->flags |= XT_DEVGROUP_MATCH_DST;
 		if (cb->invert)
diff --git a/include/xtables.h b/include/xtables.h
index e9bc3b7..4712948 100644
--- a/include/xtables.h
+++ b/include/xtables.h
@@ -537,6 +537,17 @@  extern void xtables_save_string(const char *value);
 
 extern void xtables_print_num(uint64_t number, unsigned int format);
 
+extern void xtables_parse_val_mask(struct xt_option_call *cb,
+				   unsigned int *val, unsigned int *mask,
+				   const struct xtables_lmap *lmap);
+
+static inline void xtables_parse_mark_mask(struct xt_option_call *cb,
+					   unsigned int *mark,
+					   unsigned int *mask)
+{
+	xtables_parse_val_mask(cb, mark, mask, NULL);
+}
+
 #if defined(ALL_INCLUSIVE) || defined(NO_SHARED_LIBS)
 #	ifdef _INIT
 #		undef _init
diff --git a/libxtables/xtables.c b/libxtables/xtables.c
index 57a1102..f93e88d 100644
--- a/libxtables/xtables.c
+++ b/libxtables/xtables.c
@@ -1960,6 +1960,58 @@  void xtables_print_num(uint64_t number, unsigned int format)
 	printf(FMT("%4lluT ","%lluT "), (unsigned long long)number);
 }
 
+void xtables_parse_val_mask(struct xt_option_call *cb,
+			    unsigned int *val, unsigned int *mask,
+			    const struct xtables_lmap *lmap)
+{
+	char *end;
+
+	*mask = ~0U;
+
+	if (!xtables_strtoui(cb->arg, &end, val, 0, UINT32_MAX)) {
+		if (lmap)
+			goto name2val;
+		else
+			goto bad_val;
+	}
+
+	if (*end == '\0')
+		return;
+
+	if (*end != '/') {
+		if (lmap)
+			goto name2val;
+		else
+			goto garbage;
+	}
+
+	if (!xtables_strtoui(end + 1, &end, mask, 0, UINT32_MAX))
+		goto bad_val;
+
+	if (*end == '\0')
+		return;
+
+garbage:
+	xt_params->exit_err(PARAMETER_PROBLEM,
+			"%s: trailing garbage after value "
+			"for option \"--%s\".\n",
+			cb->ext_name, cb->entry->name);
+
+bad_val:
+	xt_params->exit_err(PARAMETER_PROBLEM,
+			"%s: bad integer value for option \"--%s\", "
+			"or out of range.\n",
+			cb->ext_name, cb->entry->name);
+
+name2val:
+	*val = xtables_lmap_name2id(lmap, cb->arg);
+	if ((int)*val == -1)
+		xt_params->exit_err(PARAMETER_PROBLEM,
+			"%s: could not map name %s to an integer value "
+			"for option \"--%s\".\n",
+			cb->ext_name, cb->arg, cb->entry->name);
+}
+
 int kernel_version;
 
 void get_kernel_version(void)
diff --git a/libxtables/xtoptions.c b/libxtables/xtoptions.c
index d26d2f8..ba3128b 100644
--- a/libxtables/xtoptions.c
+++ b/libxtables/xtoptions.c
@@ -428,27 +428,7 @@  static void xtopt_parse_tosmask(struct xt_option_call *cb)
  */
 static void xtopt_parse_markmask(struct xt_option_call *cb)
 {
-	unsigned int mark = 0, mask = ~0U;
-	char *end;
-
-	if (!xtables_strtoui(cb->arg, &end, &mark, 0, UINT32_MAX))
-		xt_params->exit_err(PARAMETER_PROBLEM,
-			"%s: bad mark value for option \"--%s\", "
-			"or out of range.\n",
-			cb->ext_name, cb->entry->name);
-	if (*end == '/' &&
-	    !xtables_strtoui(end + 1, &end, &mask, 0, UINT32_MAX))
-		xt_params->exit_err(PARAMETER_PROBLEM,
-			"%s: bad mask value for option \"--%s\", "
-			"or out of range.\n",
-			cb->ext_name, cb->entry->name);
-	if (*end != '\0')
-		xt_params->exit_err(PARAMETER_PROBLEM,
-			"%s: trailing garbage after value "
-			"for option \"--%s\".\n",
-			cb->ext_name, cb->entry->name);
-	cb->val.mark = mark;
-	cb->val.mask = mask;
+	xtables_parse_mark_mask(cb, &cb->val.mark, &cb->val.mask);
 }
 
 static int xtopt_sysloglvl_compare(const void *a, const void *b)