smtp.rar_it_smtp

#include <iostream> #include <cstdlib> #include <sys/socket.h> #include <errno.h> #include <netinet/in.h> #include <netdb.h> #include <string> using namespace std; void fillClientStruct(struct sockaddr_in &server, char *ip, char *port) { server.sin_family = AF_INET; struct hostent *hp = gethostbyname(ip); //Check man gethostbyname for details of hostent if( hp==0 ) { cerr<<"Unknown Host! Error in gethostbyname()!\n"; exit(EXIT_FAILURE); } bcopy( (char *)hp->h_addr, (char *)&server.sin_addr, hp->h_length ); server.sin_port = htons(atoi(port)); } void sendUDPPacket(int sock, struct sockaddr_in &server, char *buffer) { socklen_t server_len = sizeof(server); if( sendto(sock, buffer, strlen(buffer), 0, (sockaddr *)&server, server_len) < 0 ) { cerr<<"Error : "<<errno; } } int recvUDPPacket(int sock, struct sockaddr_in &server) { char buffer[32]; socklen_t server_len; memset(buffer, '\0', sizeof(buffer)); if( recvfrom(sock, buffer, sizeof(buffer), 0, (sockaddr *)&server, &server_len)<0 ) { cerr<<"Error : "<<errno; } return atoi(buffer); } int main(int argc, char* argv[]) { if( argc!=3 ) { cerr<<"Error in format: Enter SMTP mail server's IP address and port.\n"; return EXIT_FAILURE; } int sock = socket(AF_INET, SOCK_DGRAM, 0); if( sock<0 ) { cerr<<"Error in socket()!"; return EXIT_FAILURE; } struct sockaddr_in toServer, fromServer; int responseCode; fillClientStruct(toServer, argv[1], argv[2]); char temp[32]; char fromID[32], toID[32], myDomain[32], buffer[80], messageBody[1024]; cout<<"Mail From: "; cin>>fromID; cout<<"Mail To: "; cin>>toID; cout<<"Enter the message to be sent :"; memset(messageBody, '\0', sizeof(messageBody)); do { fgets(buffer, sizeof(buffer)-1, stdin); buffer[strlen(buffer)-1] = '\0'; //Remove \n if( strcmp(buffer, ".")!=0 ) { strcat(messageBody, buffer); strcat(messageBody, "\r\n"); } }while( strcmp(buffer, ".")!=0 ); //Extract Domain strcpy(temp, strstr(fromID, "@")); if(temp != NULL) strcpy(myDomain, temp+1); else { cerr<<"Wrong email ID!"; return EXIT_FAILURE; } strcpy(temp, "HELO "); strcat(temp, myDomain); cout<<temp<<endl; sendUDPPacket(sock, toServer, temp); responseCode = recvUDPPacket(sock, fromServer); cout<<"Got Reply :"<<responseCode<<endl; strcpy(temp, "MAIL FROM:<"); strcat(temp, fromID); strcat(temp, ">"); cout<<temp<<endl; sendUDPPacket(sock, toServer, temp); responseCode = recvUDPPacket(sock, fromServer); cout<<"Server says :"<<responseCode<<endl; strcpy(temp, "RCPT TO:<"); strcat(temp, toID); strcat(temp, ">"); cout<<temp<<endl; sendUDPPacket(sock, toServer, temp); responseCode = recvUDPPacket(sock, fromServer); cout<<"Server says :"<<responseCode<<endl; cout<<"DATA"<<endl; sendUDPPacket(sock, toServer, "DATA"); responseCode = recvUDPPacket(sock, fromServer); cout<<"Server says :"<<responseCode<<endl; cout<<messageBody<<endl; sendUDPPacket(sock, toServer, messageBody); responseCode = recvUDPPacket(sock, fromServer); cout<<"Server says :"<<responseCode<<endl; cout<<'.'<<endl; sendUDPPacket(sock, toServer, "."); responseCode = recvUDPPacket(sock, fromServer); cout<<"Server says :"<<responseCode<<endl; cout<<"QUIT"<<endl; sendUDPPacket(sock, toServer, "QUIT"); responseCode = recvUDPPacket(sock, fromServer); cout<<"Server says :"<<responseCode<<endl; cout<<"Mail successfully sent!"<<endl; return EXIT_SUCCESS; }