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 method is very easy to use, with 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_noerror 0#define getmac_success getmac_noerror#define getmac_error ( -1) #define GETMAC_EATTR ( -2) Typede    f 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 n  ET */#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_AT Tr_iff_noarp 8 */NO Address Resolution Protocol */#define GETMAC_ATTR_IFF_PROMISC 9/* Receive all  Packets */#define GETMAC_ATTR_IFNAME/* Interface name, e.g. "En0".  */#define GETMAC_ATTR_IPADDR/* Address of Interface */#define GETMAC_ATTR_HWADDR//MAC Address */extern int Getmac_init (getmac_info_t * mi, getmac_error_t * err); extern int getmac_attr (getmac_info_t * mi, I NT 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 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;  }/* 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-&                GT;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].i            Fr_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 isn't 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 the 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-&gt ; 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) and #else #if 0 do {sprintf ("%02x:%02x:%02x:%02x:%02x:%02x", (unsign  Ed 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 c HAR) 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; }}

Linux obtains IP and NIC information for the machine