siphash24: let siphash24_finalize() and siphash24() return the result directly

Rather than passing a pointer to return the result, return it directly
from the function calls.

Also, return the result in native endianess, and let the callers care
about the conversion. For hash tables and bloom filters, we don't care,
but in order to keep MAC addresses and DHCP client IDs stable, we
explicitly convert to LE.

5 files changed, 10 insertions, 11 deletions

diff --git a/src/libsystemd-network/dhcp-identifier.c b/src/libsystemd-network/dhcp-identifier.c
index 368525c40a..d7ae865557 100644
--- a/src/libsystemd-network/dhcp-identifier.c
+++ b/src/libsystemd-network/dhcp-identifier.c
@@ -52,7 +52,7 @@ int dhcp_identifier_set_duid_en(struct duid *duid, size_t *len) {
 
         /* a bit of snake-oil perhaps, but no need to expose the machine-id
            directly; duid->en.id might not be aligned, so we need to copy */
-        siphash24(&hash, &machine_id, sizeof(machine_id), HASH_KEY.bytes);
+        hash = htole64(siphash24(&machine_id, sizeof(machine_id), HASH_KEY.bytes));
         memcpy(duid->en.id, &hash, sizeof(duid->en.id));
 
         return 0;
@@ -86,10 +86,12 @@ int dhcp_identifier_set_iaid(int ifindex, uint8_t *mac, size_t mac_len, void *_i
         }
 
         if (name)
-                siphash24(&id, name, strlen(name), HASH_KEY.bytes);
+                id = siphash24(name, strlen(name), HASH_KEY.bytes);
         else
                 /* fall back to MAC address if no predictable name available */
-                siphash24(&id, mac, mac_len, HASH_KEY.bytes);
+                id = siphash24(mac, mac_len, HASH_KEY.bytes);
+
+        id = htole64(id);
 
         /* fold into 32 bits */
         unaligned_write_be32(_id, (id & 0xffffffff) ^ (id >> 32));
diff --git a/src/libsystemd-network/network-internal.c b/src/libsystemd-network/network-internal.c
index ab20b6065a..6aec3da4d0 100644
--- a/src/libsystemd-network/network-internal.c
+++ b/src/libsystemd-network/network-internal.c
@@ -81,7 +81,7 @@ int net_get_unique_predictable_data(struct udev_device *device, uint64_t *result
         /* Let's hash the machine ID plus the device name. We
         * use a fixed, but originally randomly created hash
         * key here. */
-        siphash24(result, v, sz, HASH_KEY.bytes);
+        *result = htole64(siphash24(v, sz, HASH_KEY.bytes));
 
         return 0;
 }
diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c
index eeb59bb3da..277c88e2b9 100644
--- a/src/libsystemd-network/sd-dhcp-server.c
+++ b/src/libsystemd-network/sd-dhcp-server.c
@@ -753,7 +753,7 @@ int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message,
 
                         siphash24_init(&state, HASH_KEY.bytes);
                         client_id_hash_func(&req->client_id, &state);
-                        siphash24_finalize(&hash, &state);
+                        hash = htole64(siphash24_finalize(&state));
                         next_offer = hash % server->pool_size;
 
                         for (i = 0; i < server->pool_size; i++) {
diff --git a/src/libsystemd-network/sd-ipv4ll.c b/src/libsystemd-network/sd-ipv4ll.c
index e69b1864d7..006db6feee 100644
--- a/src/libsystemd-network/sd-ipv4ll.c
+++ b/src/libsystemd-network/sd-ipv4ll.c
@@ -146,12 +146,11 @@ int sd_ipv4ll_set_mac(sd_ipv4ll *ll, const struct ether_addr *addr) {
                 uint64_t seed;
 
                 /* If no random data is set, generate some from the MAC */
-                siphash24(&seed, &addr->ether_addr_octet,
-                          ETH_ALEN, HASH_KEY.bytes);
+                seed = siphash24(&addr->ether_addr_octet, ETH_ALEN, HASH_KEY.bytes);
 
                 assert_cc(sizeof(unsigned) <= 8);
 
-                r = sd_ipv4ll_set_address_seed(ll, (unsigned)seed);
+                r = sd_ipv4ll_set_address_seed(ll, (unsigned) htole64(seed));
                 if (r < 0)
                         return r;
         }
diff --git a/src/libsystemd-network/test-dhcp-server.c b/src/libsystemd-network/test-dhcp-server.c
index 62fdec46da..2b5f59e4d6 100644
--- a/src/libsystemd-network/test-dhcp-server.c
+++ b/src/libsystemd-network/test-dhcp-server.c
@@ -200,13 +200,11 @@ static void test_message_handler(void) {
 
 static uint64_t client_id_hash_helper(DHCPClientId *id, uint8_t key[HASH_KEY_SIZE]) {
         struct siphash state;
-        uint64_t hash;
 
         siphash24_init(&state, key);
         client_id_hash_func(id, &state);
-        siphash24_finalize(&hash, &state);
 
-        return hash;
+        return htole64(siphash24_finalize(&state));
 }
 
 static void test_client_id_hash(void) {