redirect output messages to stderr

4 files changed, 18 insertions, 4 deletions

diff --git a/src/fnet/arp.c b/src/fnet/arp.c
index 4736f3509..00525229e 100644
--- a/src/fnet/arp.c
+++ b/src/fnet/arp.c
@@ -192,10 +192,10 @@ void arp_scan(const char *dev, uint32_t ifip, uint32_t ifmask) {
 
                                 // printing
                                 if (header_printed == 0) {
-                                        printf("   Network scan:\n");
+                                        fmessage("   Network scan:\n");
                                         header_printed = 1;
                                 }
-                                printf("   %02x:%02x:%02x:%02x:%02x:%02x\t%d.%d.%d.%d\n",
+                                fmessage("   %02x:%02x:%02x:%02x:%02x:%02x\t%d.%d.%d.%d\n",
                                         PRINT_MAC(hdr.sender_mac), PRINT_IP(ip));
                         }
                 }
diff --git a/src/fnet/fnet.h b/src/fnet/fnet.h
index b4b7e6a37..78d6eb1c6 100644
--- a/src/fnet/fnet.h
+++ b/src/fnet/fnet.h
@@ -24,10 +24,12 @@
 #include <stdlib.h>
 #include <string.h>
 #include <assert.h>
+#include <stdarg.h>
 #include "../include/common.h"
 
 // main.c
 extern int arg_quiet;
+extern void fmessage(char* fmt, ...); // TODO: this function is duplicated in src/firejail/util.c
 
 // veth.c
 int net_create_veth(const char *dev, const char *nsdev, unsigned pid);
diff --git a/src/fnet/interface.c b/src/fnet/interface.c
index 8c1fd6ca4..d05c0d50d 100644
--- a/src/fnet/interface.c
+++ b/src/fnet/interface.c
@@ -172,7 +172,7 @@ void net_ifprint(int scan) {
         if (getifaddrs(&ifaddr) == -1)
                 errExit("getifaddrs");
 
-        printf("%-17.17s%-19.19s%-17.17s%-17.17s%-6.6s\n",
+        fmessage("%-17.17s%-19.19s%-17.17s%-17.17s%-6.6s\n",
                 "Interface", "MAC", "IP", "Mask", "Status");
         // walk through the linked list
         for (ifa = ifaddr; ifa != NULL; ifa = ifa->ifa_next) {
@@ -208,7 +208,7 @@ void net_ifprint(int scan) {
                                 sprintf(macstr, "%02x:%02x:%02x:%02x:%02x:%02x", PRINT_MAC(mac));
 
                         // print
-                        printf("%-17.17s%-19.19s%-17.17s%-17.17s%-6.6s\n",
+                        fmessage("%-17.17s%-19.19s%-17.17s%-17.17s%-6.6s\n",
                                 ifa->ifa_name, macstr, ipstr, maskstr, status);
 
                         // network scanning
diff --git a/src/fnet/main.c b/src/fnet/main.c
index f44760b5c..f746f9c7d 100644
--- a/src/fnet/main.c
+++ b/src/fnet/main.c
@@ -20,6 +20,18 @@
 #include "fnet.h"
 int arg_quiet = 0;
 
+void fmessage(char* fmt, ...) { // TODO: this function is duplicated in src/firejail/util.c
+        if (arg_quiet)
+                return;
+
+        va_list args;
+        va_start(args,fmt);
+        vfprintf(stderr, fmt, args);
+        va_end(args);
+        fflush(0);
+}
+
+
 static void usage(void) {
         printf("Usage:\n");
         printf("\tfnet create veth dev1 dev2 bridge child\n");