Code:
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
void error(char *msg)
{
perror(msg);
exit(0);
}
int main(int argc, char *argv[])
{
int sockfd, portno, n;
struct sockaddr_in serv_addr;
struct hostent *server;
char buffer[256];
if (argc < 3) {
fprintf(stderr,"usage %s hostname port\n", argv[0]);
exit(0);
}
portno = atoi(argv[2]);
sockfd = socket(AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
error("ERROR opening socket");
server = gethostbyname(argv[1]);
if (server == NULL) {
fprintf(stderr,"ERROR, no such host\n");
exit(0);
}
bzero((char *) &serv_addr, sizeof(serv_addr));
serv_addr.sin_family = AF_INET;
bcopy((char *)server->h_addr,
(char *)&serv_addr.sin_addr.s_addr,
server->h_length);
serv_addr.sin_port = htons(portno);
if (connect(sockfd,&serv_addr,sizeof(serv_addr)) < 0)
error("ERROR connecting");
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
bzero(buffer,256);
/*------------------------------*/
printf("EHLO");
strcpy(buffer,"ehlo smtp.primus.ca\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
/*------------------------------*/
printf("AUTH");
strcpy(buffer,"AUTH LOGIN\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
/*------------------------------*/
printf("AUTH UID");
strcpy(buffer,"amR1bnBoeUBwcmltdXMuY2E=\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
/*------------------------------*/
printf("AUTH PWD");
strcpy(buffer,"YXAwbGwwMTE=\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
/*------------------------------*/
printf("MAIL FROM");
strcpy(buffer,"MAIL FROM: test1@primus.ca\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
/*------------------------------*/
printf("MAIL TO");
strcpy(buffer,"RCPT TO: test2@primustel.ca\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
/*------------------------------*/
printf("DATA");
strcpy(buffer,"DATA\r\n");
n = write(sockfd,buffer,strlen(buffer));
strcpy(buffer,"Subject: test\r\n");
n = write(sockfd,buffer,strlen(buffer));
strcpy(buffer,"SMTP MAIL TOOL TEST WORKS!!!\r\n");
n = write(sockfd,buffer,strlen(buffer));
strcpy(buffer,"\n\n");
n = write(sockfd,buffer,strlen(buffer));
strcpy(buffer,".\n");
n = write(sockfd,buffer,strlen(buffer));
/*------------------------------*/
/*------------------------------*/
strcpy(buffer,"quit\n");
n = write(sockfd,buffer,strlen(buffer));
if (n < 0)
error("ERROR writing to socket");
bzero(buffer,256);
n = read(sockfd,buffer,255);
if (n < 0)
error("ERROR reading from socket");
printf("%s\n",buffer);
/*------------------------------*/
return 0;
}