Simple port checker that either takes command-line input or file input and checks each host if a given port is open.
c6196cb0030306034df4e5f018b488e74133893235f29df326bb4ff2de6299ec
/*
* port checker for bob.
* - missnglnk@tribune.intranova.net
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <fcntl.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/param.h>
#define MAXLEN 32768
extern int errno;
int
main(int argc, char **argv)
{
FILE *input;
int argswitch, fflag = 0, sflag = 0, sockfd, tport = -2,
verbose = 0;
char *ifile, *target, tmpdata[32768];
struct sockaddr_in rmt;
struct hostent *he;
unsigned long ip;
while ((argswitch = getopt(argc, argv, "f:h:p:v")) != -1) {
switch (argswitch) {
case 'f':
fflag = 1;
if (strlen(optarg) > MAXPATHLEN) {
printf("ERROR: Filename too long.\n");
return -1;
}
ifile = optarg;
break;
case 'h':
sflag = 1;
if (strlen(optarg) > MAXHOSTNAMELEN) {
printf("ERROR: Target hostname too long.\n");
return -1;
}
target = optarg;
break;
case 'p':
tport = atoi(optarg);
break;
case 'v':
verbose = 1;
break;
case '?':
default:
printf("port checker for bob.\n");
printf("%s [-f input file] [-p target port]\n", argv[0]);
printf("%s [-h single host] [-p target port]\n", argv[0]);
return -1;
break;
}
}
argc -= optind;
argv += optind;
if (sflag == 1 && fflag == 1) {
printf("ERROR: Cannot specify -f and -h together.\n");
return -1;
}
if (tport == -2) {
printf("ERROR: No port specified. (-p)\n");
return -1;
}
if (sflag == 1) {
if (verbose == 1) {
printf("Checking remote host %s\n", target);
printf("Checking port %d\n", tport);
}
if ((he = gethostbyname(target)) != NULL) {
ip = *(unsigned long *) he->h_addr;
} else if ((ip = inet_addr(target)) == NULL) {
if (verbose == 1) {
perror("Error resolving target");
}
return -1;
}
rmt.sin_family = AF_INET;
rmt.sin_addr.s_addr = ip;
rmt.sin_port = htons(tport);
if ((sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
if (verbose == 1) {
perror("Error creating socket");
}
return -1;
}
if (connect(sockfd, (struct sockaddr *) & rmt, sizeof(rmt)) == 0) {
printf("%s\n", target);
} else {
if (verbose == 1) {
perror("Error connecting");
}
}
if (close(sockfd) < 0) {
if (verbose == 1) {
perror("Error closing socket");
}
return -1;
}
} else if (fflag == 1) {
if (verbose == 1) {
printf("Reading from %s\n", ifile);
}
if ((input = fopen(ifile, "r")) == NULL) {
perror("Error opening input file");
return -1;
}
if (fread(tmpdata, MAXLEN, 1, input) < 0) {
perror("Error reading from input file");
return -1;
}
for ((target = strtok(tmpdata, "\n")); target != NULL; ((target = strtok(NULL, "\n")) != NULL)) {
if (verbose == 1) {
printf("Checking remote host %s\n", target);
printf("Checking port %d\n", tport);
}
if ((he = gethostbyname(target)) != NULL) {
ip = *(unsigned long *) he->h_addr;
} else if ((ip = inet_addr(target)) == NULL) {
if (verbose == 1) {
perror("Error resolving target");
}
}
rmt.sin_family = AF_INET;
rmt.sin_addr.s_addr = ip;
rmt.sin_port = htons(tport);
if ((sockfd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
if (verbose == 1) {
perror("Error creating socket");
}
return -1;
}
if (connect(sockfd, (struct sockaddr *) & rmt, sizeof(rmt)) == 0) {
printf("%s\n", target);
} else {
if (verbose == 1) {
perror("Error connecting");
}
}
if (close(sockfd) < 0) {
if (verbose == 1) {
perror("Error closing socket");
}
return -1;
}
}
if (fclose(input) < 0) {
perror("Error closing input");
return -1;
}
} else {
printf("ERROR: No scan type specified, bob.\n");
return -1;
}
return 0;
}