firewall3: Fix some format string problems

This adds annotations for the format strings to the print functions and
fixes the newly found problems. One of them is a format security
problem.

Coverity: #1412532
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

defaults.c

@@ -393,7 +393,7 @@ set_default(const char *name, int set)
 
 	snprintf(path, sizeof(path), "/proc/sys/net/ipv4/tcp_%s", name);
 
-	info(" * Set tcp_%s to %s", name, set ? "on" : "off", name);
+	info(" * Set tcp_%s to %s", name, set ? "on" : "off");
 
 	if (!(f = fopen(path, "w")))
 	{

includes.c

@@ -140,7 +140,7 @@ print_include(struct fw3_include *include)
 	}
 
 	while (fgets(line, sizeof(line), f))
-		fw3_pr(line);
+		fw3_pr("%s", line);
 
 	fclose(f);
 }

redirects.c

@@ -254,14 +254,13 @@ check_redirect(struct fw3_state *state, struct fw3_redirect *redir, struct uci_e
 	}
 	else if (redir->ipset.set && state->disable_ipsets)
 	{
-		warn_section("redirect", redir, e, "skipped due to disabled ipset support",
-				redir->name);
+		warn_section("redirect", redir, e, "skipped due to disabled ipset support");
 		return false;
 	}
 	else if (redir->ipset.set &&
 			!(redir->ipset.ptr = fw3_lookup_ipset(state, redir->ipset.name)))
 	{
-		warn_section("redirect", redir, e, "refers to unknown ipset '%s'", redir->name,
+		warn_section("redirect", redir, e, "refers to unknown ipset '%s'",
 				redir->ipset.name);
 		return false;
 	}

utils.h

@@ -46,10 +46,14 @@ extern bool fw3_pr_debug;
 
 struct fw3_address;
 
-void warn_elem(struct uci_element *e, const char *format, ...);
-void warn(const char *format, ...);
-void error(const char *format, ...);
-void info(const char *format, ...);
+void warn_elem(struct uci_element *e, const char *format, ...)
+	__attribute__ ((format (printf, 2, 3)));
+void warn(const char *format, ...)
+	__attribute__ ((format (printf, 1, 2)));
+void error(const char *format, ...)
+	__attribute__ ((format (printf, 1, 2)));
+void info(const char *format, ...)
+	__attribute__ ((format (printf, 1, 2)));
 
 
 #define warn_section(t, r, e, fmt, ...)					\
@@ -96,7 +100,8 @@ bool __fw3_command_pipe(bool silent, const char *command, ...);
 #define fw3_command_pipe(...) __fw3_command_pipe(__VA_ARGS__, NULL)
 
 void fw3_command_close(void);
-void fw3_pr(const char *fmt, ...);
+void fw3_pr(const char *fmt, ...)
+	__attribute__ ((format (printf, 1, 2)));
 
 bool fw3_has_table(bool ipv6, const char *table);