Linux obtains IP and NIC information for the machine

Linux obtains IP and NIC information for the machine

The code comes from the network, I rewrite, have the United States dare not self-specialized, special share. The usage is simple, just 3 functions.

Header file Getmac.h:

/** * getmac.h * * 2014-07-08:init created * * #ifndef getmac_h_included#define getmac_h_included#if defined (__cplusplus) E Xtern "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#defi    Ne getmac_success 0#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_ifname 0#define Getmac_attr_is_promiSC 1#define getmac_attr_is_up 2#define getmac_attr_ipaddr 3#define getmac_attr_hdaddr 4extern 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_inc luded * *

C File 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; } if (attr = = Getmac_attr_is_promisc | | attr = = GETMAC_ATTR_IS_UP | | attr = getmac_attr_ifname) {if (! mi-> Buf[i].ifr_name[0]) {if (IOCTL (MI->FD, Siocgifflags, (char *) & Mi->buf[i])) {err-&                Gt;errcode = errno;                  snprintf (err->errmsg, Getmac_max_msglen, "IOCTL (SIOCGIFFLAGS) error (%d):%s", Strerror (errno));            return getmac_error;            }} if (attr = = Getmac_attr_is_promisc) {/* Whether the net card status is Promisc */            if (Mi->buf[i].ifr_flags & Iff_promisc) {* ((Getmac_bool *) value) = Getmac_true;            } else {* ((Getmac_bool *) value) = Getmac_false;         }} else if (attr = = getmac_attr_is_up) {/* Whether the net card status is up */   if (Mi->buf[i].ifr_flags & iff_up) {* ((Getmac_bool *) value) = Getmac_true;            } else {* ((Getmac_bool *) value) = Getmac_false;        }} else {/* device name */strcpy (value, mi->buf[i].ifr_name);    } return getmac_success; } else if (attr = = Getmac_attr_ipaddr | | attr = = GETMAC_ATTR_HDADDR) {/* Get IP address of the net card */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; } if (attr = = getmac_attr_ipaddr) {strcpy (Value, Inet_ntoa ((struct sockaddr_in*) (& Mi->buf[i            ].IFR_ADDR)) (->SIN_ADDR));        return getmac_success; } else {/* 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*) (& BU                F[INTRFACE].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-&gt ; arp.arp_ha.sa_data[0], (unsigned char) mi->arp.arp_ha.sa_data[1], (unsig                        Ned 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]);                return getmac_success;                }} 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; } 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) m                I->BUF[I].IFR_ENADDR[4], (unsigned char) mi->buf[i].ifr_enaddr[5]); Return GETMAC_SUCCESS;    } 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; } sprintf (Value, "%02x:%02x:%02x:%02x:%02x:%02x", (unsigned char) Mi->buf[i].ifr_hwa  Ddr.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]);        return getmac_success;    } while (0);   #endif #endif}} else {err->errcode = getmac_eattr;     snprintf (err->errmsg, Getmac_max_msglen, "error attr specified");        return getmac_eattr;        }}void Getmac_fini (getmac_info_t * mi) {if (mi->fd! =-1) {close (MI->FD);    MI->FD =-1; }}