1 files changed, 25 insertions, 8 deletions

diff --git a/hbbpd.c b/hbbpd.c
index e24cf55..f47cd28 100644
--- a/hbbpd.c
+++ b/hbbpd.c
@@ -2,19 +2,23 @@
 ** listener.c -- a datagram sockets "server" demo
 */
 
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/wait.h>
+
 #include "common.h"
+#include "crypto.h"
 
 int main(int argc, char **argv, char **envp) {
   int fd;
   int numbytes;
   struct sockaddr_storage their_addr;
-  char buf[MAXBUFLEN];
+  byte buf[MAXBUFLEN];
   socklen_t addr_len;
 
   /* setup socket, parse cmd line */
   {
     struct sockaddr_in6 ba;
-    struct ipv6_mreq ga;
     if (argc > 2) {
       fprintf(stderr, "usage: %s [interface]\n", argv[0]);
       exit(1);
@@ -55,15 +59,28 @@ int main(int argc, char **argv, char **envp) {
   addr_len = sizeof their_addr;
   while ((numbytes = recvfrom(fd, buf, MAXBUFLEN-1 , 0,
 			      (struct sockaddr *) &their_addr, &addr_len)) != -1) {
-    /* decode packet & launch handler */
+    /* decode packet */
     buf[numbytes] = '\0';
-    char *task = buf,
-      *cl_argv[2] = {task, NULL};
+    char *task = (char*) buf;
+    int task_len = strlen(task);
+    byte *payload = buf + task_len + 1;
+    int payload_len = numbytes - task_len - 1;
+
     if (task[0] == '/' || strstr(task, "..")) {
       fprintf(stderr, "payload tried directory traversal\n");
       continue;
     }
 
+    /* TODO: check if the task exists and is executable; save cpu
+       cycles trying to decode messages not intended for us */
+
+    /* decipher packet */
+    if (!decipher(task, &payload, &payload_len)) {
+      fprintf(stderr, "unable to decrypt payload\n");
+      continue;
+    }
+
+    /* launch handler */
     int fd_payload[2];
     ENP(pipe(fd_payload), "pipe");
       
@@ -76,6 +93,7 @@ int main(int argc, char **argv, char **envp) {
       ENP(close(fd),             "close");
 
       /* run our task task */
+      char *cl_argv[2] = {task, NULL};
       execve(task, cl_argv, envp);
       perror("exec");
       exit(1);
@@ -86,9 +104,8 @@ int main(int argc, char **argv, char **envp) {
 
     /* write payload to child process; the return value of write is
        intentionally ignored */
-    int tasklen = strlen(task);
-    if (tasklen < numbytes)
-      write(fd_payload[1], buf + tasklen + 1, numbytes - tasklen - 1);
+    if (task_len < numbytes)
+      IGN(write(fd_payload[1], payload, payload_len)) 
     ENP(close(fd_payload[1]), "close");
     ENP(close(fd_payload[0]), "close");
     ENP(wait(NULL), "wait");