tftp: fix bad interaction betweel poll() and alarm(). Closes bug 3061

This was breaking timeout handling.

function                                             old     new   delta
tftp_progress_update                                   -      45     +45
tftp_progress_done                                     -      32     +32
tftp_protocol                                       1839    1858     +19
tftp_progress_init                                     9      15      +6
tftp_main                                            298     286     -12
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 2/1 up/down: 102/-12)            Total: 90 bytes

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>

2 files changed, 13 insertions, 28 deletions

diff --git a/libbb/progress.c b/libbb/progress.c
index 4c2763c53..74e80a39e 100644
--- a/libbb/progress.c
+++ b/libbb/progress.c
@@ -78,7 +78,7 @@ void FAST_FUNC bb_progress_update(bb_progress_t *p,
         /* Do not update on every call
          * (we can be called on every network read!) */
         if (since_last_update == 0 && !totalsize)
-                        return;
+                return;
 
         beg_and_transferred = beg_range + transferred;
         ratio = 100;
diff --git a/networking/tftp.c b/networking/tftp.c
index 04c8f0ebb..fcd933f6a 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -105,39 +105,22 @@ struct BUG_G_too_big {
 #define error_pkt_str    (error_pkt + 4)
 
 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
-/* SIGALRM logic nicked from the wget applet */
-static void progress_meter(int flag)
+static void tftp_progress_update(void)
 {
-        /* We can be called from signal handler */
-        int save_errno = errno;
-
-        if (flag == -1) { /* first call to progress_meter */
-                bb_progress_init(&G.pmt);
-        }
-
         bb_progress_update(&G.pmt, G.file, 0, G.pos, G.size);
-
-        if (flag == 0) {
-                /* last call to progress_meter */
-                alarm(0);
-                bb_putchar_stderr('\n');
-        } else {
-                if (flag == -1) { /* first call to progress_meter */
-                        signal_SA_RESTART_empty_mask(SIGALRM, progress_meter);
-                }
-                alarm(1);
-        }
-
-        errno = save_errno;
 }
 static void tftp_progress_init(void)
 {
-        progress_meter(-1);
+        bb_progress_init(&G.pmt);
+        tftp_progress_update();
 }
 static void tftp_progress_done(void)
 {
-        if (G.pmt.inited)
-                progress_meter(0);
+        if (G.pmt.inited) {
+                tftp_progress_update();
+                bb_putchar_stderr('\n');
+                G.pmt.inited = 0;
+        }
 }
 #else
 # define tftp_progress_init() ((void)0)
@@ -460,9 +443,10 @@ static int tftp_protocol(
                 xsendto(socket_fd, xbuf, send_len, &peer_lsa->u.sa, peer_lsa->len);
 
 #if ENABLE_FEATURE_TFTP_PROGRESS_BAR
-                if (ENABLE_TFTP && remote_file) { /* tftp */
+                if (ENABLE_TFTP && remote_file) /* tftp */
                         G.pos = (block_nr - 1) * (uoff_t)blksize;
-                }
+                if (G.pmt.inited)
+                        tftp_progress_update();
 #endif
                 /* Was it final ACK? then exit */
                 if (finished && (opcode == TFTP_ACK))
@@ -479,6 +463,7 @@ static int tftp_protocol(
                 case 0:
                         retries--;
                         if (retries == 0) {
+                                tftp_progress_done();
                                 bb_error_msg("timeout");
                                 goto ret; /* no err packet sent */
                         }