diff options
| -rw-r--r-- | src/network/networkd-netdev.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/src/network/networkd-netdev.c b/src/network/networkd-netdev.c index b7fc48db94..075a8790a0 100644 --- a/src/network/networkd-netdev.c +++ b/src/network/networkd-netdev.c @@ -25,6 +25,7 @@ #include "conf-files.h" #include "conf-parser.h" #include "list.h" +#include "siphash24.h" #define VLANID_MAX 4094 @@ -180,8 +181,48 @@ static int netdev_create_handler(sd_rtnl *rtnl, sd_rtnl_message *m, void *userda return 1; } +#define HASH_KEY SD_ID128_MAKE(52,e1,45,bd,00,6f,29,96,21,c6,30,6d,83,71,04,48) + +static int netdev_get_mac(NetDev *netdev, struct ether_addr *mac) { + uint8_t result[8]; + size_t l, sz; + uint8_t *v; + int r; + + assert(netdev); + assert(netdev->name); + assert(mac); + + l = strlen(netdev->name); + sz = sizeof(sd_id128_t) + l; + v = alloca(sz); + + /* fetch some persistent data unique to the machine */ + r = sd_id128_get_machine((sd_id128_t*) v); + if (r < 0) + return r; + + /* combine with some data unique (on this machine) to this + * netdev */ + memcpy(v + sizeof(sd_id128_t), netdev->name, l); + + /* Let's hash the host machine ID plus the container name. We + * use a fixed, but originally randomly created hash key here. */ + siphash24(result, v, sz, HASH_KEY.bytes); + + assert_cc(ETH_ALEN <= sizeof(result)); + memcpy(mac->ether_addr_octet, result, ETH_ALEN); + + /* see eth_random_addr in the kernel */ + mac->ether_addr_octet[0] &= 0xfe; /* clear multicast bit */ + mac->ether_addr_octet[0] |= 0x02; /* set local assignment bit (IEEE802) */ + + return 0; +} + static int netdev_create(NetDev *netdev, Link *link, sd_rtnl_message_handler_t callback) { _cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL; + struct ether_addr mac; const char *kind; int r; @@ -192,6 +233,12 @@ static int netdev_create(NetDev *netdev, Link *link, sd_rtnl_message_handler_t c assert(netdev->manager); assert(netdev->manager->rtnl); + r = netdev_get_mac(netdev, &mac); + if (r < 0) { + log_error("Failed to generate predictable MAC address for %s", netdev->name); + return r; + } + r = sd_rtnl_message_new_link(netdev->manager->rtnl, &req, RTM_NEWLINK, 0); if (r < 0) { log_error_netdev(netdev, @@ -218,6 +265,14 @@ static int netdev_create(NetDev *netdev, Link *link, sd_rtnl_message_handler_t c return r; } + r = sd_rtnl_message_append_ether_addr(req, IFLA_ADDRESS, &mac); + if (r < 0) { + log_error_netdev(netdev, + "Colud not append IFLA_ADDRESS attribute: %s", + strerror(-r)); + return r; + } + r = sd_rtnl_message_open_container(req, IFLA_LINKINFO); if (r < 0) { log_error_netdev(netdev, |