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POLinked List in C and getifaddrs()
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copied!<p>I've a problem with linked list. I'm using getifaddrs() to get ifaces info in Linux.</p> <p>At first, i created an struct for save the interfaces infos.</p> <p>This is a struct:</p> <pre><code> typedef struct iface { char * interface_name; char * interface_addr_ipv4; char * interface_addr_ipv6; char * interface_netmask; char * interface_broadcast; char * interface_mac_addr; int interface_active; struct iface * next_interface; } Interface; </code></pre> <p>After this, i identify all ifaces of system in this way, even if they are not configured with an IP:</p> <pre><code> if (getifaddrs(&ifaddr) == -1) return GET_INFO_IFACES_FAILED; struct iface * iface_aux; struct ifaddrs * ifaddr_aux; struct sockaddr_in * ip; iface_aux = iface; for (ifaddr_aux=ifaddr;ifaddr_aux!=NULL;ifaddr_aux=ifaddr_aux->ifa_next) { iface_aux->interface_name = ifaddr_aux->ifa_name; if (ip->sin_family == AF_PACKET) { get_interface_mac_addr(iface_aux); iface_aux->interface_addr_ipv4 = NULL; iface_aux->interface_addr_ipv6 = NULL; iface_aux->next_interface = (Interface *) malloc(sizeof (Interface)); iface_aux = iface_aux->next_interface; iface_aux->next_interface = NULL; } } </code></pre> <p>After all this, i do other loop to get ip address of interfaces, this is the code:</p> <pre><code>iface_aux = iface; //go to the firts pointer for (ifaddr_aux=ifaddr;ifaddr_aux!=NULL;ifaddr_aux=ifaddr_aux->ifa_next) { ip = (struct sockaddr_in *) ifaddr_aux->ifa_addr; if (ip->sin_family == AF_INET) { get_interface_ifaddr(iface_aux, ip); get_interface_netmask(iface_aux, ifaddr); get_interface_broadcast(iface_aux, ifaddr); iface_aux = iface_aux->next_interface; } } </code></pre> <p>The code of function get_interface_ifaddr is:</p> <pre><code>int get_interface_ifaddr(Interface * iface, struct sockaddr_in * ip) { iface->interface_addr_ipv4 = inet_ntoa(ip->sin_addr); if (iface->interface_addr_ipv4 == NULL) return GET_IFADDR_FAILED; return GET_IPADDR_SUCCESS; } </code></pre> <p>The problem is, when i do another loop to see the interfaces infos, all nodes of the list, stay with the last ip:</p> <pre><code>for (iface_aux=iface;iface_aux->next_interface!=NULL;iface_aux=iface_aux->next_interface) { printf("Interface Name: %s\n", iface_aux->interface_name); printf("Interface IP: %s\n", iface_aux->interface_addr_ipv4); } </code></pre> <p>The strange thing is that the name of the interfaces is correct, but when i get the address, all nodes of the list, are to the same address.</p> <p>Someone know what is going on?</p> <p>PS: i'm new in c and linked list.</p> <p>Thanks for your atention.</p>

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