only read as much as fits inside of a GNUNET_Message

diff --git a/src/vpn/gnunet-vpn-helper.c b/src/vpn/gnunet-vpn-helper.c
index 1d0b1ad28821f2f69c22094fe7fc71f17eea76b5..4a75182f9a893821ebd17abaa789e4b6841bdbaa 100644 (file)
--- a/src/vpn/gnunet-vpn-helper.c
+++ b/src/vpn/gnunet-vpn-helper.c
@@ -48,6 +48,8 @@
 #ifndef _LINUX_IN6_H
 // This is in linux/include/net/ipv6.h.
 
+#define MAX_SIZE (65535 - sizeof(struct GNUNET_MessageHeader))
+
 struct in6_ifreq {
     struct in6_addr ifr6_addr;
     __u32 ifr6_prefixlen;
@@ -112,7 +114,7 @@ void setnonblocking(int fd) {/*{{{*/
 }/*}}}*/
 
 int main(int argc, char** argv) {
-       unsigned char buf[65600]; // 64k + 64;
+       unsigned char buf[MAX_SIZE];
 
        char dev[IFNAMSIZ];
        memset(dev, 0, IFNAMSIZ);
@@ -203,7 +205,7 @@ outer:
                                }
                        } else if (write_stdout_possible && FD_ISSET(fd_tun, &fds_r)) {
                                write_stdout_possible = 0;
-                               r = read(fd_tun, buf, 65600);
+                               r = read(fd_tun, buf, MAX_SIZE);
                                if (r <= 0) {
                                        fprintf(stderr, "read-error: %m\n");
                                        shutdown(fd_tun, SHUT_RD);