Linux 获得机器的IP和网卡信息

代码来自于网络, 我改写了, 有美不敢自专, 特分享之.用法很简单,就3个函数.

头文件getmac.h:

/** * getmac.h * * 2014-07-08: init created */#ifndef GETMAC_H_INCLUDED#define GETMAC_H_INCLUDED#if defined(__cplusplus)extern "C" {#endif#include <stdio.h>#include <string.h>#include <errno.h>#include <sys/types.h>#include <sys/param.h>#include <sys/ioctl.h>#include <sys/socket.h>#include <net/if.h>#include <netinet/in.h>#include <net/if_arp.h>#include <arpa/inet.h>#include <unistd.h>#ifdef SOLARIS# include <sys/sockio.h>#endif#define GETMAC_MAX_INTERFACES   16#define GETMAC_MAX_MSGLEN      256#define GETMAC_NOERROR    0#define GETMAC_SUCCESS  GETMAC_NOERROR#define GETMAC_ERROR    (-1)#define GETMAC_EATTR    (-2)typedef int GETMAC_BOOL;#define GETMAC_TRUE    1#define GETMAC_FALSE   0typedef struct{    int fd;    struct ifreq buf[GETMAC_MAX_INTERFACES];    struct arpreq arp;    int ifaces;} getmac_info_t;typedef struct{    int errcode;    char errmsg[GETMAC_MAX_MSGLEN];} getmac_error_t;#define GETMAC_ATTR_IFF_UP          1       /* Interface is up */#define GETMAC_ATTR_IFF_BROADCAST   2       /* Broadcast address valid */#define GETMAC_ATTR_IFF_DEBUG       3       /* Turn on debugging */#define GETMAC_ATTR_IFF_LOOPBACK    4       /* Is a loopback net */#define GETMAC_ATTR_IFF_POINTOPOINT 5       /* Interface is point-to-point link */#define GETMAC_ATTR_IFF_NOTRAILERS  6       /* Avoid use of trailers */#define GETMAC_ATTR_IFF_RUNNING     7       /* Resources allocated */#define GETMAC_ATTR_IFF_NOARP       8       /* No address resolution protocol */#define GETMAC_ATTR_IFF_PROMISC     9       /* Receive all packets */#define GETMAC_ATTR_IFNAME         10       /* Interface name, e.g. "en0".  */#define GETMAC_ATTR_IPADDR         11       /* Address of interface */#define GETMAC_ATTR_HWADDR         12       /* MAC address */extern int getmac_init (getmac_info_t * mi, getmac_error_t * err);extern int getmac_attr (getmac_info_t * mi, int i, int attr, void * value, getmac_error_t * err);extern void getmac_fini (getmac_info_t * mi);#if defined(__cplusplus)}#endif#endif /* GETMAC_H_INCLUDED */

C文件getmac.c:

/** * getmac.c * * 2014-07-08: init created */#include "getmac.h"int getmac_init (getmac_info_t * mi, getmac_error_t * err){    int fd;    struct ifconf ifc;    bzero (mi, sizeof(getmac_info_t));    mi->fd = -1;    fd = socket (AF_INET, SOCK_DGRAM, 0);    if (fd == -1) {        err->errcode = errno;        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "socket() error (%d): %s", strerror(errno));        return GETMAC_ERROR;    }    /* prepare to get mac numb */    ifc.ifc_len = sizeof(mi->buf);    ifc.ifc_buf = (caddr_t) mi->buf;    if (ioctl (fd, SIOCGIFCONF, (char *) &ifc)) {        err->errcode = errno;        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl() error (%d): %s", strerror(errno));        close (fd);        return GETMAC_ERROR;    }    mi->ifaces = ifc.ifc_len / sizeof (struct ifreq);    mi->fd = fd;    /* return numb of mac */    return mi->ifaces;}int getmac_attr (getmac_info_t * mi, int i, int attr, void * value, getmac_error_t * err){    if (mi->fd == -1) {        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "getmac_init should be invoked first");        return GETMAC_ERROR;    }    /* initialize if not a valid name */    if (! mi->buf[i].ifr_name[0]) {        if (ioctl (mi->fd, SIOCGIFFLAGS, (char *) & mi->buf[i])) {            err->errcode = errno;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl(SIOCGIFFLAGS) error (%d): %s", strerror(errno));              return GETMAC_ERROR;        }                if (ioctl (mi->fd, SIOCGIFADDR, (char *) & mi->buf[i])) {            err->errcode = errno;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl(SIOCGIFADDR) error (%d): %s", strerror(errno));              return GETMAC_ERROR;        }                /* get Hardware Address */#ifdef SOLARIS        do {            mi->arp.arp_pa.sa_family = AF_INET;            mi->arp.arp_ha.sa_family = AF_INET;            ((struct sockaddr_in *) & mi->arp.arp_pa)->sin_addr.s_addr = ((struct sockaddr_in*)(& buf[i].ifr_addr))->sin_addr.s_addr;            if ((ioctl (mi->fd, SIOCGARP, (char *) & mi->arp))) {                err->errcode = errno;                snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl(SIOCGARP) error (%d): %s", strerror(errno));                  return GETMAC_ERROR;            }        } while (0);#else    #if 0        do {            /* get HW ADDRESS of the net card */            if (ioctl (mi->fd, SIOCGENADDR, (char *) & buf[i])) {                err->errcode = errno;                snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl(SIOCGENADDR) error (%d): %s", strerror(errno));                  return GETMAC_ERROR;            }        } while (0);    #else        do {            if (ioctl (mi->fd, SIOCGIFHWADDR, (char *) & mi->buf[i])) {                err->errcode = errno;                snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl(SIOCGIFHWADDR) error (%d): %s", strerror(errno));                  return GETMAC_ERROR;            }        } while (0);    #endif#endif           }    err->errcode = GETMAC_NOERROR;    /* get net attribute */    switch (attr) {    case GETMAC_ATTR_IFF_UP:    /* Interface is up */        if (mi->buf[i].ifr_flags & IFF_UP) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Interface is up");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Interface is not up");        }        break;        case GETMAC_ATTR_IFF_BROADCAST:    /* Broadcast address valid */        if (mi->buf[i].ifr_flags & IFF_BROADCAST) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Broadcast address valid");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Broadcast address invalid");        }        break;        case GETMAC_ATTR_IFF_DEBUG:    /* Turn on debugging */        if (mi->buf[i].ifr_flags & IFF_DEBUG) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Turn on debugging");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Turn off debugging");        }        break;        case GETMAC_ATTR_IFF_LOOPBACK:    /* Is a loopback net */        if (mi->buf[i].ifr_flags & IFF_LOOPBACK) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Is a loopback net");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Not a loopback net");        }        break;        case GETMAC_ATTR_IFF_POINTOPOINT:    /* Interface is point-to-point link */        if (mi->buf[i].ifr_flags & IFF_POINTOPOINT) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Interface is point-to-point link");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Interface is not point-to-point link");        }        break;        case GETMAC_ATTR_IFF_NOTRAILERS:    /* Avoid use of trailers */        if (mi->buf[i].ifr_flags & IFF_NOTRAILERS) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Avoid use of trailers");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Not Avoid use of trailers");        }        break;        case GETMAC_ATTR_IFF_RUNNING:    /* Resources allocated */        if (mi->buf[i].ifr_flags & IFF_RUNNING) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Resources allocated");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Resources not allocated");        }        break;        case GETMAC_ATTR_IFF_NOARP:    /* No address resolution protocol */        if (mi->buf[i].ifr_flags & IFF_NOARP) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "No address resolution protocol");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Has address resolution protocol");        }           break;    case GETMAC_ATTR_IFF_PROMISC:    /* Receive all packets */        if (mi->buf[i].ifr_flags & IFF_PROMISC) {            * ((GETMAC_BOOL *) value) = GETMAC_TRUE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Receive all packets");        } else {            * ((GETMAC_BOOL *) value) = GETMAC_FALSE;            snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Not a promisc mode");        }        break;    case GETMAC_ATTR_IFNAME:    /* Interface name, e.g. "en0" */        strcpy (value, mi->buf[i].ifr_name);        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Interface name");        break;        case GETMAC_ATTR_IPADDR:    /* Interface address */        strcpy (value, inet_ntoa (((struct sockaddr_in*) (& mi->buf[i].ifr_addr))->sin_addr));        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "Interface address");        break;        case GETMAC_ATTR_HWADDR:#ifdef SOLARIS        do {            mi->arp.arp_pa.sa_family = AF_INET;            mi->arp.arp_ha.sa_family = AF_INET;            ((struct sockaddr_in *) & mi->arp.arp_pa)->sin_addr.s_addr = ((struct sockaddr_in*)(& buf[i].ifr_addr))->sin_addr.s_addr;            if ((ioctl (mi->fd, SIOCGARP, (char *) & mi->arp))) {                err->errcode = errno;                snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "ioctl(SIOCGARP) error (%d): %s", strerror(errno));                  return GETMAC_ERROR;            } else {                sprintf (value, "%02x:%02x:%02x:%02x:%02x:%02x",                    (unsigned char) mi->arp.arp_ha.sa_data[0],                    (unsigned char) mi->arp.arp_ha.sa_data[1],                    (unsigned char) mi->arp.arp_ha.sa_data[2],                    (unsigned char) mi->arp.arp_ha.sa_data[3],                    (unsigned char) mi->arp.arp_ha.sa_data[4],                    (unsigned char) mi->arp.arp_ha.sa_data[5] );            }        } while (0);#else    #if 0        do {            sprintf("%02x:%02x:%02x:%02x:%02x:%02x",                (unsigned char) mi->buf[i].ifr_enaddr[0],                (unsigned char) mi->buf[i].ifr_enaddr[1],                (unsigned char) mi->buf[i].ifr_enaddr[2],                (unsigned char) mi->buf[i].ifr_enaddr[3],                (unsigned char) mi->buf[i].ifr_enaddr[4],                (unsigned char) mi->buf[i].ifr_enaddr[5]);        } while (0);    #else        do {            sprintf (value, "%02x:%02x:%02x:%02x:%02x:%02x",                (unsigned char) mi->buf[i].ifr_hwaddr.sa_data[0],                (unsigned char) mi->buf[i].ifr_hwaddr.sa_data[1],                (unsigned char) mi->buf[i].ifr_hwaddr.sa_data[2],                (unsigned char) mi->buf[i].ifr_hwaddr.sa_data[3],                (unsigned char) mi->buf[i].ifr_hwaddr.sa_data[4],                (unsigned char) mi->buf[i].ifr_hwaddr.sa_data[5]);        } while (0);    #endif#endif        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "MAC address");        break;    default:        err->errcode = GETMAC_EATTR;        snprintf (err->errmsg, GETMAC_MAX_MSGLEN, "error attr specified");        return GETMAC_EATTR;    }    return GETMAC_SUCCESS;}void getmac_fini (getmac_info_t * mi){    if (mi->fd != -1) {        close (mi->fd);        mi->fd = -1;    }}