From: Zbigniew Jędrzejewski-Szmek Date: Sat, 19 Jan 2019 14:19:03 +0000 (+0100) Subject: udev: add debug logging about the choice of MAC X-Git-Tag: v242-rc1~332^2~1 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=015b097cce608df59f862f2202d128704abc1724;p=thirdparty%2Fsystemd.git udev: add debug logging about the choice of MAC --- diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c index 0fda4d16b9a..60da08a86ff 100644 --- a/src/udev/net/link-config.c +++ b/src/udev/net/link-config.c @@ -187,19 +187,19 @@ static bool enable_name_policy(void) { return proc_cmdline_get_bool("net.ifnames", &b) <= 0 || b; } -static int link_name_type(sd_device *device, unsigned *type) { +static int link_unsigned_attribute(sd_device *device, const char *attr, unsigned *type) { const char *s; int r; - r = sd_device_get_sysattr_value(device, "name_assign_type", &s); + r = sd_device_get_sysattr_value(device, attr, &s); if (r < 0) - return log_device_debug_errno(device, r, "Failed to query name_assign_type: %m"); + return log_device_debug_errno(device, r, "Failed to query %s: %m", attr); r = safe_atou(s, type); if (r < 0) - return log_device_warning_errno(device, r, "Failed to parse name_assign_type \"%s\": %m", s); + return log_device_warning_errno(device, r, "Failed to parse %s \"%s\": %m", attr, s); - log_device_debug(device, "Device has name_assign_type=%d", *type); + log_device_debug(device, "Device has %s=%u", attr, *type); return 0; } @@ -265,11 +265,9 @@ int link_config_get(link_config_ctx *ctx, sd_device *device, link_config **ret) devtype, sysname)) { if (link->match_name) { - unsigned char name_assign_type = NET_NAME_UNKNOWN; - const char *attr_value; + unsigned name_assign_type = NET_NAME_UNKNOWN; - if (sd_device_get_sysattr_value(device, "name_assign_type", &attr_value) >= 0) - (void) safe_atou8(attr_value, &name_assign_type); + (void) link_unsigned_attribute(device, "name_assign_type", &name_assign_type); if (name_assign_type == NET_NAME_ENUM) { log_warning("Config file %s applies to device based on potentially unpredictable interface name '%s'", @@ -297,33 +295,41 @@ int link_config_get(link_config_ctx *ctx, sd_device *device, link_config **ret) return -ENOENT; } -static bool mac_is_random(sd_device *device) { - const char *s; - unsigned type; +static int get_mac(sd_device *device, MACPolicy policy, struct ether_addr *mac) { + unsigned addr_type; + bool want_random = policy == MACPOLICY_RANDOM; int r; - /* if we can't get the assign type, assume it is not random */ - if (sd_device_get_sysattr_value(device, "addr_assign_type", &s) < 0) - return false; + assert(IN_SET(policy, MACPOLICY_RANDOM, MACPOLICY_PERSISTENT)); - r = safe_atou(s, &type); + r = link_unsigned_attribute(device, "addr_assign_type", &addr_type); if (r < 0) - return false; - - return type == NET_ADDR_RANDOM; -} + return r; + switch (addr_type) { + case NET_ADDR_SET: + return log_device_debug(device, "MAC on the device already set by userspace"); + case NET_ADDR_STOLEN: + return log_device_debug(device, "MAC on the device already set based on another device"); + case NET_ADDR_RANDOM: + case NET_ADDR_PERM: + break; + default: + return log_device_warning(device, "Unknown addr_assign_type %u, ignoring", addr_type); + } -static int get_mac(sd_device *device, bool want_random, struct ether_addr *mac) { - int r; + if (want_random == (addr_type == NET_ADDR_RANDOM)) + return log_device_debug(device, "MAC on the device already matches policy *%s*", + mac_policy_to_string(policy)); - if (want_random) + if (want_random) { + log_device_debug(device, "Using random bytes to generate MAC"); random_bytes(mac->ether_addr_octet, ETH_ALEN); - else { + } else { uint64_t result; r = net_get_unique_predictable_data(device, &result); if (r < 0) - return r; + return log_device_warning_errno(device, r, "Could not generate persistent MAC: %m"); assert_cc(ETH_ALEN <= sizeof(result)); memcpy(mac->ether_addr_octet, &result, ETH_ALEN); @@ -332,8 +338,7 @@ static int get_mac(sd_device *device, bool want_random, struct ether_addr *mac) /* 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; + return 1; } int link_config_apply(link_config_ctx *ctx, link_config *config, @@ -397,7 +402,7 @@ int link_config_apply(link_config_ctx *ctx, link_config *config, return log_device_warning_errno(device, r, "Could not find ifindex: %m"); - (void) link_name_type(device, &name_type); + (void) link_unsigned_attribute(device, "name_assign_type", &name_type); if (IN_SET(name_type, NET_NAME_USER, NET_NAME_RENAMED) && !naming_scheme_has(NAMING_ALLOW_RERENAMES)) { @@ -454,33 +459,11 @@ int link_config_apply(link_config_ctx *ctx, link_config *config, log_device_debug(device, "Policies didn't yield a name and Name= is not given, not renaming."); no_rename: - switch (config->mac_policy) { - case MACPOLICY_PERSISTENT: - if (mac_is_random(device)) { - r = get_mac(device, false, &generated_mac); - if (r == -ENODATA) { - log_warning_errno(r, "Could not generate persistent MAC address for %s: %m", old_name); - break; - } else if (r < 0) - return r; - mac = &generated_mac; - } - break; - case MACPOLICY_RANDOM: - if (!mac_is_random(device)) { - r = get_mac(device, true, &generated_mac); - if (r == -ENODATA) { - log_warning_errno(r, "Could not generate random MAC address for %s: %m", old_name); - break; - } else if (r < 0) - return r; - mac = &generated_mac; - } - break; - case MACPOLICY_NONE: - default: - mac = config->mac; - } + if (IN_SET(config->mac_policy, MACPOLICY_PERSISTENT, MACPOLICY_RANDOM)) { + if (get_mac(device, config->mac_policy, &generated_mac) > 0) + mac = &generated_mac; + } else + mac = config->mac; r = rtnl_set_link_properties(&ctx->rtnl, ifindex, config->alias, mac, config->mtu); if (r < 0)