From b9ef8fbd63fface91ff3cd98d7d702f9827c322d Mon Sep 17 00:00:00 2001
From: Ryan Schanzenbacher <ryan@rschanz.org>
Date: Mon, 20 Mar 2023 18:03:45 -0400
Subject: organization

---
 ping_senders/ping3.c | 110 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 110 insertions(+)
 create mode 100644 ping_senders/ping3.c

(limited to 'ping_senders/ping3.c')

diff --git a/ping_senders/ping3.c b/ping_senders/ping3.c
new file mode 100644
index 0000000..f0dd858
--- /dev/null
+++ b/ping_senders/ping3.c
@@ -0,0 +1,110 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <netinet/in_systm.h>
+#include <netinet/ip.h>
+#include <netinet/ip_icmp.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <sys/select.h>
+
+unsigned short cksum(unsigned short *addr, int len);
+
+int main(int argc, char *argv[]) {
+    int sock;
+    char send_buf[400], src_ip[15], dst_ip[15], src_name[256];
+    struct ip *ip = (struct ip *)send_buf;
+    struct icmp *icmp = (struct icmp *)(ip + 1);
+    struct hostent *src_hp, *dst_hp;
+    struct sockaddr_in src, dst;
+    int on = 1;
+    memset(send_buf, 0, sizeof(send_buf));
+
+    if (argc < 2) {
+        printf("Need arg. I\n");
+        exit(EXIT_FAILURE);
+    }
+
+    /**if (getuid() == 0) {
+        fprintf(stderr, "Need to elevate\n");
+        exit(EXIT_FAILURE);
+    } **/
+    
+    gethostname(src_name, sizeof(src_name));
+    printf("%s\n", src_name);
+    src_hp = gethostbyname(src_name);
+    ip->ip_src = (*(struct in_addr *)src_hp->h_addr_list[0]);
+
+    dst_hp = gethostbyname(argv[1]);
+    ip->ip_dst = (*(struct in_addr *)dst_hp->h_addr);
+    dst.sin_addr = (*(struct in_addr *)dst_hp->h_addr);
+
+    sprintf(src_ip, "%s", inet_ntoa(ip->ip_src));
+    sprintf(dst_ip, "%s", inet_ntoa(ip->ip_dst));
+    printf("Src: %s -- Dst: %s\n", src_ip, dst_ip);
+
+    // Create socket
+    sock = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
+
+    setsockopt(sock, IPPROTO_IP, IP_HDRINCL, &on, sizeof(on));
+
+    // IP Structure
+    ip->ip_v = 4;
+    ip->ip_hl = 5;
+    ip->ip_tos = 0;
+    ip->ip_len = htons(sizeof(send_buf));
+    ip->ip_id = htons(321);
+    ip->ip_off = htons(0);
+    ip->ip_ttl = 255;
+    ip->ip_p = IPPROTO_ICMP;
+    ip->ip_sum = 0;
+
+    // ICMP Structure
+    icmp->icmp_type = 2;
+    icmp->icmp_code = 0;
+    
+    dst.sin_family = AF_INET;
+
+    ip->ip_sum = cksum((unsigned short *)send_buf, ip->ip_hl);
+    icmp->icmp_cksum = cksum((unsigned short *)icmp, sizeof(send_buf) - sizeof(struct icmp));
+
+    int dst_addr_len = sizeof(dst);
+    int bytes_sent;
+
+    if((bytes_sent = sendto(sock, send_buf, sizeof(send_buf), 0, (struct sockaddr *)&dst, dst_addr_len)) < 0) {
+        perror("send err");
+        fflush(stdout);
+    }
+    else {
+        printf("Sent %d bytes\n", bytes_sent);
+    }
+
+
+}
+
+unsigned short cksum(unsigned short *addr, int len) {
+    int nleft = len;
+    int sum = 0;
+    unsigned short *w = addr;
+    unsigned short answer = 0;
+
+    while (nleft > 1) {
+        sum += *w++;
+        nleft -= 2;
+    }
+
+    if (nleft == 1) {
+        *(unsigned char *)(&answer) = *(unsigned char *)w;
+        sum += answer;
+    }
+
+    sum = (sum >> 16) + (sum & 0xffff);
+    sum += (sum >> 16);
+    answer = ~sum;
+
+    return answer;
+}
-- 
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