From 0b36e0a77fc750af85e969efda7bda0931f389d0 Mon Sep 17 00:00:00 2001
From: Gerrit Renker <gerrit.renker@googlemail.com>
Date: Tue, 30 Jun 2009 10:17:16 +0200
Subject: [PATCH] Make allow/deny syntax consistent with that of add/delete

After the changes for the add/delete commands, this patch updates
allow/deny to use the same syntax and (almost) the same code.
---
 acl.c         | 30 ++++++++----------------------
 command.c     | 12 ++----------
 net.c         | 41 +++++++++++++++++++++++++++++++++++++++++
 net.h         |  2 ++
 send_common.c |  5 +++--
 5 files changed, 56 insertions(+), 34 deletions(-)

diff --git a/acl.c b/acl.c
index 14edcf7d..9bc83c25 100644
--- a/acl.c
+++ b/acl.c
@@ -136,30 +136,16 @@ char *acl_get_contents(struct list_head *acl)
  */
 void acl_init(struct list_head *acl, char * const *acl_info, int num)
 {
-	int i;
+	char	addr[16];
+	int	mask, i;
 
 	INIT_LIST_HEAD(acl);
-	for (i = 0; i < num; i++) {
-		char *arg = para_strdup(acl_info[i]);
-		char *p = strchr(arg, '/');
-		int netmask;
-
-		if (!p)
-			goto err;
-		*p = '\0';
-		if (!is_valid_ipv4_address(arg))
-			goto err;
-		netmask = atoi(++p);
-		if (netmask < 0 || netmask > 32)
-			goto err;
-		acl_add_entry(acl, arg, netmask);
-		goto success;
-err:
-		PARA_CRIT_LOG("syntax error: %s\n", acl_info[i]);
-success:
-		free(arg);
-		continue;
-	}
+	for (i = 0; i < num; i++)
+		if (parse_cidr(acl_info[i], addr, sizeof(addr), &mask) == NULL)
+			PARA_CRIT_LOG("ACL syntax error: %s, ignoring\n",
+				      acl_info[i]);
+		else
+			acl_add_entry(acl, addr, mask);
 }
 
 /**
diff --git a/command.c b/command.c
index 1ca54da9..e3b15a5a 100644
--- a/command.c
+++ b/command.c
@@ -185,17 +185,9 @@ static int check_sender_args(int argc, char * const * argv, struct sender_comman
 		break;
 	case SENDER_DENY:
 	case SENDER_ALLOW:
-		if (argc != 4 && argc != 5)
+		if (argc != 4 || parse_cidr(argv[3], scd->host,
+				sizeof(scd->host), &scd->netmask) == NULL)
 			return -E_COMMAND_SYNTAX;
-		if (!is_valid_ipv4_address(argv[3]))
-			return -E_COMMAND_SYNTAX;
-		scd->netmask = 32;
-		if (argc == 5) {
-			scd->netmask = atoi(argv[4]);
-			if (scd->netmask < 0 || scd->netmask > 32)
-				return -E_COMMAND_SYNTAX;
-		}
-		strncpy(scd->host, argv[3], sizeof(scd->host));
 		break;
 	case SENDER_ADD:
 	case SENDER_DELETE:
diff --git a/net.c b/net.c
index 7207e528..ab6a9894 100644
--- a/net.c
+++ b/net.c
@@ -92,6 +92,47 @@ void disable_crypt(int fd)
 	crypt_data_array[fd].private_data = NULL;
 }
 
+/**
+ * Parse and validate IPv4 address/netmask string.
+ *
+ * \param cidr	  Address in CIDR notation
+ * \param addr	  Copy of the IPv4 address part of \a cidr
+ * \param addrlen Size of \a addr in bytes
+ * \param netmask Value of the netmask part in \a cidr or the
+ *		  default of 32 if not specified.
+ *
+ * \return Pointer to \a addr if succesful, NULL on error.
+ * \sa RFC 4632
+ */
+char *parse_cidr(const char *cidr,
+		 char	 *addr, ssize_t addrlen,
+		 int32_t *netmask)
+{
+	const char *o = cidr;
+	char *c = addr, *end = c + (addrlen - 1);
+
+	*netmask = 0x20;
+
+	if (cidr == NULL || addrlen < 1)
+		goto failed;
+
+	for (o = cidr; (*c = *o == '/'? '\0' : *o); c++, o++)
+		if (c == end)
+			goto failed;
+
+	if (*o == '/')
+		if (para_atoi32(++o, netmask) < 0 ||
+		    *netmask < 0 || *netmask > 0x20)
+			goto failed;
+
+	if (is_valid_ipv4_address(addr))
+		return addr;
+failed:
+	*addr = '\0';
+	return NULL;
+}
+
+
 /**
  * Match string as a candidate IPv4 address.
  *
diff --git a/net.h b/net.h
index 11b1708f..8b706178 100644
--- a/net.h
+++ b/net.h
@@ -29,6 +29,8 @@
 /**
  * Functions to parse and validate (parts of) URLs.
  */
+extern char *parse_cidr(const char *cidr,
+			char *addr, ssize_t addrlen, int32_t *netmask);
 extern char *parse_url(const char *url,
 		       char *host, ssize_t hostlen, int32_t *port);
 /**
diff --git a/send_common.c b/send_common.c
index b8160073..200e59ab 100644
--- a/send_common.c
+++ b/send_common.c
@@ -389,8 +389,9 @@ char *generic_sender_help(void)
 {
 	return make_message(
 		"usage: {on|off}\n"
-		"usage: {allow|deny} IP mask\n"
-		"example: allow 127.0.0.1 32\n"
+		"usage: {allow|deny} IP[/netmask]\n"
+		"       where mask defaults to 32\n"
+		"example: allow 192.168.0.1/24\n"
 	);
 }
 
-- 
2.39.2