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shared: switch our hash table implementation over to SipHash
[elogind.git]
/
src
/
udev
/
net
/
link-config.c
diff --git
a/src/udev/net/link-config.c
b/src/udev/net/link-config.c
index 9b91d9d145884f98b778467de76c97d66f20a248..e6618b8cbfc99d742c463c9739eaca8074e41b35 100644
(file)
--- a/
src/udev/net/link-config.c
+++ b/
src/udev/net/link-config.c
@@
-39,6
+39,7
@@
#include "hashmap.h"
#include "rtnl-util.h"
#include "net-util.h"
#include "hashmap.h"
#include "rtnl-util.h"
#include "net-util.h"
+#include "siphash24.h"
struct link_config_ctx {
LIST_HEAD(link_config, links);
struct link_config_ctx {
LIST_HEAD(link_config, links);
@@
-301,17
+302,18
@@
static bool mac_is_permanent(struct udev_device *device) {
return type == 0;
}
return type == 0;
}
+#define HASH_KEY SD_ID128_MAKE(d3,1e,48,fa,90,fe,4b,4c,9d,af,d5,d7,a1,b1,2e,8a)
+
static int get_mac(struct udev_device *device, bool want_random, struct ether_addr *mac) {
static int get_mac(struct udev_device *device, bool want_random, struct ether_addr *mac) {
- unsigned int seed;
- int r, i;
+ int r;
if (want_random)
if (want_random)
-
seed = random_u(
);
+
random_bytes(mac->ether_addr_octet, ETH_ALEN
);
else {
const char *name;
else {
const char *name;
-
sd_id128_t machine
;
-
char machineid_buf[33]
;
-
const char *seed_str
;
+
uint8_t result[8]
;
+
size_t l, sz
;
+
uint8_t *v
;
/* fetch some persistent data unique (on this machine) to this device */
name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
/* fetch some persistent data unique (on this machine) to this device */
name = udev_device_get_property_value(device, "ID_NET_NAME_ONBOARD");
@@
-323,22
+325,24
@@
static int get_mac(struct udev_device *device, bool want_random, struct ether_ad
return -ENOENT;
}
}
return -ENOENT;
}
}
+
+ l = strlen(name);
+ sz = sizeof(sd_id128_t) + l;
+ v = alloca(sz);
+
/* fetch some persistent data unique to this machine */
/* fetch some persistent data unique to this machine */
- r = sd_id128_get_machine(
&machine
);
+ r = sd_id128_get_machine(
(sd_id128_t*) v
);
if (r < 0)
return r;
if (r < 0)
return r;
+ memcpy(v + sizeof(sd_id128_t), name, l);
- /* combine the data */
- seed_str = strappenda(name, sd_id128_to_string(machine, machineid_buf));
-
- /* hash to get seed */
- seed = string_hash_func(seed_str);
- }
-
- srandom(seed);
+ /* 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);
- for (i = 0; i < ETH_ALEN; i++) {
- m
ac->ether_addr_octet[i] = random(
);
+ assert_cc(ETH_ALEN <= sizeof(result));
+ m
emcpy(mac->ether_addr_octet, result, ETH_ALEN
);
}
/* see eth_random_addr in the kernel */
}
/* see eth_random_addr in the kernel */