ネットワーク・インタフェース毎のリンク速度はethtoolコマンドを使えば以下の様に確認できるが、
# ethtool eth0
Settings for eth0:
Supported ports: [ TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 1
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbag
Wake-on: g
Current message level: 0x00000001 (1)
Link detected: yes
プログラムから同様の事を行うには、ioctl(SIOCETHTOOL)を以下の様に叩けば良い。
#include <linux/ethtool.h>
int getlinkspeed(char *ifname)
{
struct ethtool_value ethval;
struct ethtool_cmd ethcmd;
struct ifreq ifr;
int fd_tmp, linkspd = 1000; /* A unit is Mbps. */
/* open control socket */
fd_tmp = socket(AF_INET, SOCK_DGRAM, 0);
if ( fd_tmp < ZERO ){
return ZERO;
}
/* init query structure */
memset(&ifr, 0x00, sizeof(struct ifreq));
strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
/* Query:LinkUp ? */
ethval.cmd = ETHTOOL_GLINK;
ifr.ifr_data = (caddr_t)ðval;
if ( !ioctl(fd_tmp, SIOCETHTOOL, &ifr) && ethval.data ){
/* LinkUp !! */
/* Query:GetSettings */
ethcmd.cmd = ETHTOOL_GSET;
ifr.ifr_data = (caddr_t)ðcmd;
if( !ioctl(fd_tmp, SIOCETHTOOL, &ifr) ){
linkspd = ethcmd.speed;
}
} else {
/* Query failed */
linkspd = ZERO;
}
close(fd_tmp);
return linkspd;
}
参照
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