selftests/net: Refactor xfrm_fill_key() to use array of structs

A TODO in net/ipsec.c asks to refactor the code in xfrm_fill_key() to
use set/map to avoid manually comparing each algorithm with the "name"
parameter passed to the function as an argument. This patch refactors
the code to create an array of structs where each struct contains the
algorithm name and its corresponding key length.
Signed-off-by: Gautam Menghani <gautammenghani201@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

tools/testing/selftests/net/ipsec.c

@@ -58,6 +58,8 @@
 #define VETH_FMT	"ktst-%d"
 #define VETH_LEN	12
 
+#define XFRM_ALGO_NR_KEYS 29
+
 static int nsfd_parent	= -1;
 static int nsfd_childa	= -1;
 static int nsfd_childb	= -1;
@@ -75,6 +77,43 @@ const unsigned int ping_timeout		= 300;
 const unsigned int ping_count		= 100;
 const unsigned int ping_success		= 80;
 
+struct xfrm_key_entry {
+	char algo_name[35];
+	int key_len;
+};
+
+struct xfrm_key_entry xfrm_key_entries[] = {
+	{"digest_null", 0},
+	{"ecb(cipher_null)", 0},
+	{"cbc(des)", 64},
+	{"hmac(md5)", 128},
+	{"cmac(aes)", 128},
+	{"xcbc(aes)", 128},
+	{"cbc(cast5)", 128},
+	{"cbc(serpent)", 128},
+	{"hmac(sha1)", 160},
+	{"hmac(rmd160)", 160},
+	{"cbc(des3_ede)", 192},
+	{"hmac(sha256)", 256},
+	{"cbc(aes)", 256},
+	{"cbc(camellia)", 256},
+	{"cbc(twofish)", 256},
+	{"rfc3686(ctr(aes))", 288},
+	{"hmac(sha384)", 384},
+	{"cbc(blowfish)", 448},
+	{"hmac(sha512)", 512},
+	{"rfc4106(gcm(aes))-128", 160},
+	{"rfc4543(gcm(aes))-128", 160},
+	{"rfc4309(ccm(aes))-128", 152},
+	{"rfc4106(gcm(aes))-192", 224},
+	{"rfc4543(gcm(aes))-192", 224},
+	{"rfc4309(ccm(aes))-192", 216},
+	{"rfc4106(gcm(aes))-256", 288},
+	{"rfc4543(gcm(aes))-256", 288},
+	{"rfc4309(ccm(aes))-256", 280},
+	{"rfc7539(chacha20,poly1305)-128", 0}
+};
+
 static void randomize_buffer(void *buf, size_t buflen)
 {
 	int *p = (int *)buf;
@@ -767,65 +806,12 @@ static int do_ping(int cmd_fd, char *buf, size_t buf_len, struct in_addr from,
 static int xfrm_fill_key(char *name, char *buf,
 		size_t buf_len, unsigned int *key_len)
 {
-	/* TODO: use set/map instead */
-	if (strncmp(name, "digest_null", ALGO_LEN) == 0)
-		*key_len = 0;
-	else if (strncmp(name, "ecb(cipher_null)", ALGO_LEN) == 0)
-		*key_len = 0;
-	else if (strncmp(name, "cbc(des)", ALGO_LEN) == 0)
-		*key_len = 64;
-	else if (strncmp(name, "hmac(md5)", ALGO_LEN) == 0)
-		*key_len = 128;
-	else if (strncmp(name, "cmac(aes)", ALGO_LEN) == 0)
-		*key_len = 128;
-	else if (strncmp(name, "xcbc(aes)", ALGO_LEN) == 0)
-		*key_len = 128;
-	else if (strncmp(name, "cbc(cast5)", ALGO_LEN) == 0)
-		*key_len = 128;
-	else if (strncmp(name, "cbc(serpent)", ALGO_LEN) == 0)
-		*key_len = 128;
-	else if (strncmp(name, "hmac(sha1)", ALGO_LEN) == 0)
-		*key_len = 160;
-	else if (strncmp(name, "hmac(rmd160)", ALGO_LEN) == 0)
-		*key_len = 160;
-	else if (strncmp(name, "cbc(des3_ede)", ALGO_LEN) == 0)
-		*key_len = 192;
-	else if (strncmp(name, "hmac(sha256)", ALGO_LEN) == 0)
-		*key_len = 256;
-	else if (strncmp(name, "cbc(aes)", ALGO_LEN) == 0)
-		*key_len = 256;
-	else if (strncmp(name, "cbc(camellia)", ALGO_LEN) == 0)
-		*key_len = 256;
-	else if (strncmp(name, "cbc(twofish)", ALGO_LEN) == 0)
-		*key_len = 256;
-	else if (strncmp(name, "rfc3686(ctr(aes))", ALGO_LEN) == 0)
-		*key_len = 288;
-	else if (strncmp(name, "hmac(sha384)", ALGO_LEN) == 0)
-		*key_len = 384;
-	else if (strncmp(name, "cbc(blowfish)", ALGO_LEN) == 0)
-		*key_len = 448;
-	else if (strncmp(name, "hmac(sha512)", ALGO_LEN) == 0)
-		*key_len = 512;
-	else if (strncmp(name, "rfc4106(gcm(aes))-128", ALGO_LEN) == 0)
-		*key_len = 160;
-	else if (strncmp(name, "rfc4543(gcm(aes))-128", ALGO_LEN) == 0)
-		*key_len = 160;
-	else if (strncmp(name, "rfc4309(ccm(aes))-128", ALGO_LEN) == 0)
-		*key_len = 152;
-	else if (strncmp(name, "rfc4106(gcm(aes))-192", ALGO_LEN) == 0)
-		*key_len = 224;
-	else if (strncmp(name, "rfc4543(gcm(aes))-192", ALGO_LEN) == 0)
-		*key_len = 224;
-	else if (strncmp(name, "rfc4309(ccm(aes))-192", ALGO_LEN) == 0)
-		*key_len = 216;
-	else if (strncmp(name, "rfc4106(gcm(aes))-256", ALGO_LEN) == 0)
-		*key_len = 288;
-	else if (strncmp(name, "rfc4543(gcm(aes))-256", ALGO_LEN) == 0)
-		*key_len = 288;
-	else if (strncmp(name, "rfc4309(ccm(aes))-256", ALGO_LEN) == 0)
-		*key_len = 280;
-	else if (strncmp(name, "rfc7539(chacha20,poly1305)-128", ALGO_LEN) == 0)
-		*key_len = 0;
+	int i;
+
+	for (i = 0; i < XFRM_ALGO_NR_KEYS; i++) {
+		if (strncmp(name, xfrm_key_entries[i].algo_name, ALGO_LEN) == 0)
+			*key_len = xfrm_key_entries[i].key_len;
+	}
 
 	if (*key_len > buf_len) {
 		printk("Can't pack a key - too big for buffer");