From 6099c78436a93ab677d0cb35a815cdd55bad279b Mon Sep 17 00:00:00 2001
From: Kyle K <kylek389@gmail.com>
Date: Thu, 24 Nov 2011 01:01:56 -0600
Subject: few cleanups

---
 tcpflow.c | 39 +++++++++++++--------------------------
 1 file changed, 13 insertions(+), 26 deletions(-)

diff --git a/tcpflow.c b/tcpflow.c
index 5bbce43..998eb1c 100644
--- a/tcpflow.c
+++ b/tcpflow.c
@@ -37,10 +37,10 @@ struct tcpflow
     tcp_seq initial_seq;
     unsigned int packet_count, bytes_count;
     int fd;
-    struct tcpflow *next;
     char ip_src_s[16];
     char ip_dst_s[16];
-    char session_fname[50];
+    char session_fname[64];
+    struct tcpflow *next;
 };
 typedef struct tcpflow tcpflow_t;
 
@@ -56,10 +56,6 @@ int check_session(tcpflow_t *list, struct in_addr ip_src, struct in_addr ip_dst,
         if (iter->ip_src.s_addr == ip_src.s_addr && iter->ip_dst.s_addr == ip_dst.s_addr &&
             iter->src_port == src_port && iter->dst_port == dst_port)
         {
-#if 0
-            printf("same session detected, session = %s, packets = %u, bytes = %u\n",
-            iter->session_fname, iter->packet_count, iter->bytes_count);
-#endif
             *session_ptr = iter;
             return 0;
         }
@@ -88,14 +84,14 @@ int add_session(tcpflow_t **list, struct ip *ip_pkt, struct tcphdr *tcp_pkt)
         node->src_port = ntohs(tcp_pkt->th_sport);
         node->dst_port = ntohs(tcp_pkt->th_dport);
         node->initial_seq = ntohl(tcp_pkt->th_seq);
-        node->bytes_count += ((ntohs(ip_pkt->ip_len) - 20 - (tcp_pkt->th_off * 4))); /* calc payload */
+        node->bytes_count += ((ntohs(ip_pkt->ip_len) - 20 - (tcp_pkt->th_off << 2))); /* calc payload */
         strcpy(node->ip_src_s, inet_ntoa(ip_pkt->ip_src));
         strcpy(node->ip_dst_s, inet_ntoa(ip_pkt->ip_dst));
 
-        char buff[50] = { 0 };
+        char buff[64] = { 0 };
         sprintf(buff, "%s.%u-%s.%u.logs", node->ip_src_s, node->src_port,
         node->ip_dst_s, node->dst_port);
-        strncpy(node->session_fname, buff, 50);
+        strncpy(node->session_fname, buff, 64);
 
         /* open file for writing */
         char fname[300] = { 0 };
@@ -103,13 +99,8 @@ int add_session(tcpflow_t **list, struct ip *ip_pkt, struct tcphdr *tcp_pkt)
         if ((node->fd = open(fname, O_WRONLY | O_CREAT, 0644)) == -1)
             perror("failed to create file for tcp session");
 
-        if (!*list)
-            *list = node;
-        else
-        {
-            node->next = *list;
-            *list = node;
-        }
+        node->next = *list;
+        *list = node;
     }
     else
     {
@@ -123,24 +114,21 @@ int add_session(tcpflow_t **list, struct ip *ip_pkt, struct tcphdr *tcp_pkt)
 int cont_session(tcpflow_t *curr_session, struct ip *ip_pkt, struct tcphdr *tcp_pkt)
 {
     /* calc payload */
-    unsigned int payload = (ntohs(ip_pkt->ip_len) - 20 - (tcp_pkt->th_off * 4));
+    unsigned int payload = (ntohs(ip_pkt->ip_len) - 20 - (tcp_pkt->th_off << 2));
 
     if (!payload && (tcp_pkt->th_flags & TH_ACK)) /* silly to check for ACK flag? It's always set after handshake, eh */
     {
-        fprintf(stderr, "%s is ACKing\n", curr_session->ip_src_s); /* or possibly finishing a 3-way handshake */
+        /* or possibly finishing a 3-way handshake */
+        fprintf(stderr, "%s is ACKing\n", curr_session->ip_src_s);
         return 0;
     }
 
     /* append payload, if any */
     if (payload && curr_session->fd)
     {
-        void *payload_addr = ((char *) (tcp_pkt)) + tcp_pkt->th_off * 4;
-#if 0
-        printf("tcp header is at: %p\n", tcp_pkt);
-        printf("payload is at: %p and size = %u\n", payload_addr, payload);
-#endif
-
-        lseek(curr_session->fd, ntohl(tcp_pkt->th_seq) - curr_session->initial_seq, SEEK_SET); /* seek to some offset from beginning */
+        void *payload_addr = ((char *) (tcp_pkt)) + (tcp_pkt->th_off << 2);
+        /* seek to some offset from beginning */
+        lseek(curr_session->fd, ntohl(tcp_pkt->th_seq) - curr_session->initial_seq, SEEK_SET);
         write(curr_session->fd, payload_addr, payload);
         curr_session->bytes_count += payload;
 
@@ -152,7 +140,6 @@ int cont_session(tcpflow_t *curr_session, struct ip *ip_pkt, struct tcphdr *tcp_
     }
 
     curr_session->packet_count++;
-
     return 0;
 }
 
-- 
cgit v1.2.3