[ECOS] Could not follow the Route initialisation code

["Kaustubh Purandare" <kaustubh_purandare at rediffmail dot com>]

Hi,

I was debugging the function init_net() present in 
boot_support.c

I am unable to follow the piece of code given below

strcpy(ifr.ifr_name, intf);
     if (ioctl(s, strcpy(ifr.ifr_name, intf);
     if (ioctl(s, SIOCSIFADDR, &ifr)) {
         perror("SIOCIFADDR");
         return false;
     }

     if (get_bootp_option(bp, TAG_SUBNET_MASK, &addrp->sin_addr)) 
{
         netmask = addrp->sin_addr;
         if (ioctl(s, SIOCSIFNETMASK, &ifr)) {
             perror("SIOCSIFNETMASK");
             return false;
         }
         // Must do this again so that [sub]netmask (and so 
default route)
         // is taken notice of.
         addrp->sin_addr = bp->bp_yiaddr;  // The address BOOTP 
gave us
         if (ioctl(s, SIOCSIFADDR, &ifr)) {
             perror("SIOCIFADDR 2");
             return false;
         }
     }

     if (get_bootp_option(bp, TAG_IP_BROADCAST, &addrp->sin_addr)) 
{
         if (ioctl(s, SIOCSIFBRDADDR, &ifr)) {
             perror("SIOCSIFBRDADDR");
             return false;
         }
         // Do not re-set the IFADDR after this; doing *that* 
resets the
         // BRDADDR to the default!
     }

     ifr.ifr_flags = IFF_UP | IFF_BROADCAST | IFF_RUNNING;
     if (ioctl(s, SIOCSIFFLAGS, &ifr)) {
         perror("SIOCSIFFLAGS");
         return false;, &ifr)) {
         perror("SIOCIFADDR");
         return false;
     }

     if (get_bootp_option(bp, TAG_SUBNET_MASK, &addrp->sin_addr)) 
{
         netmask = addrp->sin_addr;
         if (ioctl(s, SIOCSIFNETMASK, &ifr)) {
             perror("SIOCSIFNETMASK");
             return false;
         }
         // Must do this again so that [sub]netmask (and so 
default route)
         // is taken notice of.
         addrp->sin_addr = bp->bp_yiaddr;  // The address BOOTP 
gave us
         if (ioctl(s, SIOCSIFADDR, &ifr)) {
             perror("SIOCIFADDR 2");
             return false;
         }
     }

     if (get_bootp_option(bp, TAG_IP_BROADCAST, &addrp->sin_addr)) 
{
         if (ioctl(s, SIOCSIFBRDADDR, &ifr)) {
             perror("SIOCSIFBRDADDR");
             return false;
         }
         // Do not re-set the IFADDR after this; doing *that* 
resets the
         // BRDADDR to the default!
     }

     ifr.ifr_flags = IFF_UP | IFF_BROADCAST | IFF_RUNNING;
     if (ioctl(s, SIOCSIFFLAGS, &ifr)) {
         perror("SIOCSIFFLAGS");
         return false;

Why two ioctl's function are called for only one command
SIOCSIFADDR it appears to be setting the IP address again. Kindly 
help me clarify what this function does

Regards,

Kaustubh




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