package/maccalc: don't expect to get all data in one read

Signed-off-by: Alexander Gordeev <lasaine@lvk.cs.msu.su>
SVN-Revision: 28266

diff --git a/package/maccalc/src/main.c b/package/maccalc/src/main.c
index e1e12cd96f27292a772a1a8b2e62323efb81689b..dcb5f55c55dd4e0af18ec9d1f35e6eedb67dc402 100644 (file)
--- a/package/maccalc/src/main.c
+++ b/package/maccalc/src/main.c
@@ -9,6 +9,7 @@
  *
  */
 
+#include <errno.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdint.h>
@@ -124,6 +125,34 @@ static int maccalc_do_mac2bin(int argc, const char *argv[])
        return 0;
 }
 
+static ssize_t read_safe(int fd, void *buf, size_t count)
+{
+       ssize_t total = 0;
+       ssize_t r;
+
+       while(count > 0) {
+               r = read(fd, buf, count);
+               if (r == 0)
+                       /* EOF */
+                       break;
+               if (r < 0) {
+                       if (errno == EINTR)
+                               /* interrupted by a signal, restart */
+                               continue;
+                       /* error */
+                       total = -1;
+                       break;
+               }
+
+               /* ok */
+               total += r;
+               count -= r;
+               buf += r;
+       }
+
+       return total;
+}
+
 static int maccalc_do_bin2mac(int argc, const char *argv[])
 {
        unsigned char mac[MAC_ADDRESS_LEN];
@@ -134,7 +163,7 @@ static int maccalc_do_bin2mac(int argc, const char *argv[])
                return ERR_INVALID;
        }
 
-       c = read(STDIN_FILENO, mac, sizeof(mac));
+       c = read_safe(STDIN_FILENO, mac, sizeof(mac));
        if (c != sizeof(mac)) {
                fprintf(stderr, "failed to read from stdin\n");
                return ERR_IO;