I am creating a UDP server and it is working but, i would like to do some ip comparisons and break them down t thestring representive
say for instance i want to check for a specific ip 192.168.1.1 and if that address send a different message back than my normal
this is what i have so far
o1, o2, o3 & o4 are the string representives of each octet of the ip
when compiling i get passing argument 1 of sscanf makes pointer from integer without cast
i want to rid that, but it seems as if the strings are present
for storing the ip in a string i tried to use
full code so farCode:sscanf("%s",inet_ntoa(addr.sin_addr),uip);
Code:#include <stdio.h> #include <stdlib.h> #include <errno.h> #include <sys/socket.h> #include <resolv.h> #include <string.h> #define DEFAULT_UDP_PORT 1234 int main(int count, char *strings[]) { int sd; // int i; //use for counter int fport; //from port int lastport = 0; //set last port for compare to from port int uport; //upper byte of from port int lport; //lower byte of from port int sbytes = 20; //# of bytes to send back int users; //number of users on irc server int port=DEFAULT_UDP_PORT; struct sockaddr_in addr; char buffer[32]; //receive buffer char sbuffer[32]; //send buffer char temp[32]={0x0}; //results of netstat char o1[5], o2[5], o3[5], o4[5]; //set string rep of each octet int io1, io2, io3, io4; //set int value for each octet if ( count != 2 ) printf("usage: %s <port>\n...Using UDP default port (%d).\n", strings[0], port); else port = atoi(strings[1]); sd = socket(PF_INET, SOCK_DGRAM, 0); bzero(&addr, sizeof(addr)); addr.sin_family = AF_INET; addr.sin_port = htons(port); addr.sin_addr.s_addr = INADDR_ANY; if ( bind(sd, (struct sockaddr*)&addr, sizeof(addr)) != 0 ) perror("bind"); while (1) { int bytes, addr_len=sizeof(addr); bytes = recvfrom(sd, buffer, sizeof(buffer), 0, (struct sockaddr*)&addr, &addr_len); //sscanf(inet_ntoa(addr.sin_addr), "%hu.%hu.%hu.%hu", &ip[0],&ip[1],&ip[2],&ip[3]); sscanf(inet_ntoa(addr.sin_addr), "%4[^.].%4[^.].%4[^.].%4[^.]", o1, o2, o3, o4); //set from port to port received from fport = ntohs(addr.sin_port); //set upper byte of port uport = fport / 256; //set lower byte of port lport = fport - (uport * 256); //int of each octet io1 = atoi(o1); io2 = atoi(o2); io3 = atoi(o3); io4 = atoi(o4); sbuffer[0] = 'h'; sbuffer[1] = 'i'; sbuffer[2] = ' '; sbuffer[3] = 'b'; sbuffer[4] = 'y'; sbuffer[5] = 'e'; //test different ip here and change message sendto(sd,sbuffer,sbytes,0, (struc sockaddr*)&addr, sizeof(addr)); } close(sd); }
Originally Posted by TomChesley
