From: Holger Hans Peter Freyther <[email protected]>
Instead of doing open/read/close all the time, open the
FD in the beginning and keep it open. To scare me even
more I have seen /dev/urandom actually providing a short
read and then blocking but it seems to be the best way
to get the random byes we need for authentication.
So one should/could run the cheap random generator on
the system (e.g. haveged) or deal with the NAT process
to block.
---
openbsc/include/openbsc/bsc_nat.h | 3 +++
openbsc/src/osmo-bsc_nat/bsc_nat.c | 9 +++++++++
2 files changed, 12 insertions(+)
diff --git a/openbsc/include/openbsc/bsc_nat.h
b/openbsc/include/openbsc/bsc_nat.h
index 6921441..1035937 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -304,6 +304,9 @@ struct bsc_nat {
/* control interface */
struct ctrl_handle *ctrl;
+
+ /* for random values */
+ int random_fd;
};
struct bsc_nat_ussd_con {
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c
b/openbsc/src/osmo-bsc_nat/bsc_nat.c
index 841262c..82562ba 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c
@@ -21,6 +21,8 @@
*
*/
#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/stat.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
@@ -31,6 +33,7 @@
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
+#include <fcntl.h>
#define _GNU_SOURCE
#include <getopt.h>
@@ -1534,6 +1537,12 @@ int main(int argc, char **argv)
/* We need to add mode-set for amr codecs */
nat->sdp_ensure_amr_mode_set = 1;
+ nat->random_fd = open("/dev/random", O_RDONLY);
+ if (nat->random_fd < 0) {
+ fprintf(stderr, "Failed to open /dev/urandom.\n");
+ return -5;
+ }
+
vty_info.copyright = openbsc_copyright;
vty_init(&vty_info);
logging_vty_add_cmds(&log_info);
--
2.3.5
