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IABSD.fr/src/usr.bin/ssh/progressmeter.c

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  • Author : dtucker
    Date : 2020-01-23 07:10:22
    Hash : e9716d4d
    Message : Replace all calls to signal(2) with a wrapper around sigaction(2). This wrapper blocks all other signals during the handler preventing races between handlers, and sets SA_RESTART which should reduce the potential for short read/write operations.

  • usr.bin/ssh/progressmeter.c
  • /* $OpenBSD: progressmeter.c,v 1.50 2020/01/23 07:10:22 dtucker Exp $ */
    /*
     * Copyright (c) 2003 Nils Nordman.  All rights reserved.
     *
     * Redistribution and use in source and binary forms, with or without
     * modification, are permitted provided that the following conditions
     * are met:
     * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     */
    
    #include <sys/types.h>
    #include <sys/ioctl.h>
    #include <sys/uio.h>
    
    #include <errno.h>
    #include <signal.h>
    #include <stdarg.h>
    #include <stdio.h>
    #include <string.h>
    #include <time.h>
    #include <unistd.h>
    
    #include "progressmeter.h"
    #include "atomicio.h"
    #include "misc.h"
    #include "utf8.h"
    
    #define DEFAULT_WINSIZE 80
    #define MAX_WINSIZE 512
    #define PADDING 1		/* padding between the progress indicators */
    #define UPDATE_INTERVAL 1	/* update the progress meter every second */
    #define STALL_TIME 5		/* we're stalled after this many seconds */
    
    /* determines whether we can output to the terminal */
    static int can_output(void);
    
    /* formats and inserts the specified size into the given buffer */
    static void format_size(char *, int, off_t);
    static void format_rate(char *, int, off_t);
    
    /* window resizing */
    static void sig_winch(int);
    static void setscreensize(void);
    
    /* signal handler for updating the progress meter */
    static void sig_alarm(int);
    
    static double start;		/* start progress */
    static double last_update;	/* last progress update */
    static const char *file;	/* name of the file being transferred */
    static off_t start_pos;		/* initial position of transfer */
    static off_t end_pos;		/* ending position of transfer */
    static off_t cur_pos;		/* transfer position as of last refresh */
    static volatile off_t *counter;	/* progress counter */
    static long stalled;		/* how long we have been stalled */
    static int bytes_per_second;	/* current speed in bytes per second */
    static int win_size;		/* terminal window size */
    static volatile sig_atomic_t win_resized; /* for window resizing */
    static volatile sig_atomic_t alarm_fired;
    
    /* units for format_size */
    static const char unit[] = " KMGT";
    
    static int
    can_output(void)
    {
    	return (getpgrp() == tcgetpgrp(STDOUT_FILENO));
    }
    
    static void
    format_rate(char *buf, int size, off_t bytes)
    {
    	int i;
    
    	bytes *= 100;
    	for (i = 0; bytes >= 100*1000 && unit[i] != 'T'; i++)
    		bytes = (bytes + 512) / 1024;
    	if (i == 0) {
    		i++;
    		bytes = (bytes + 512) / 1024;
    	}
    	snprintf(buf, size, "%3lld.%1lld%c%s",
    	    (long long) (bytes + 5) / 100,
    	    (long long) (bytes + 5) / 10 % 10,
    	    unit[i],
    	    i ? "B" : " ");
    }
    
    static void
    format_size(char *buf, int size, off_t bytes)
    {
    	int i;
    
    	for (i = 0; bytes >= 10000 && unit[i] != 'T'; i++)
    		bytes = (bytes + 512) / 1024;
    	snprintf(buf, size, "%4lld%c%s",
    	    (long long) bytes,
    	    unit[i],
    	    i ? "B" : " ");
    }
    
    void
    refresh_progress_meter(int force_update)
    {
    	char buf[MAX_WINSIZE + 1];
    	off_t transferred;
    	double elapsed, now;
    	int percent;
    	off_t bytes_left;
    	int cur_speed;
    	int hours, minutes, seconds;
    	int file_len;
    
    	if ((!force_update && !alarm_fired && !win_resized) || !can_output())
    		return;
    	alarm_fired = 0;
    
    	if (win_resized) {
    		setscreensize();
    		win_resized = 0;
    	}
    
    	transferred = *counter - (cur_pos ? cur_pos : start_pos);
    	cur_pos = *counter;
    	now = monotime_double();
    	bytes_left = end_pos - cur_pos;
    
    	if (bytes_left > 0)
    		elapsed = now - last_update;
    	else {
    		elapsed = now - start;
    		/* Calculate true total speed when done */
    		transferred = end_pos - start_pos;
    		bytes_per_second = 0;
    	}
    
    	/* calculate speed */
    	if (elapsed != 0)
    		cur_speed = (transferred / elapsed);
    	else
    		cur_speed = transferred;
    
    #define AGE_FACTOR 0.9
    	if (bytes_per_second != 0) {
    		bytes_per_second = (bytes_per_second * AGE_FACTOR) +
    		    (cur_speed * (1.0 - AGE_FACTOR));
    	} else
    		bytes_per_second = cur_speed;
    
    	/* filename */
    	buf[0] = '\0';
    	file_len = win_size - 36;
    	if (file_len > 0) {
    		buf[0] = '\r';
    		snmprintf(buf+1, sizeof(buf)-1, &file_len, "%-*s",
    		    file_len, file);
    	}
    
    	/* percent of transfer done */
    	if (end_pos == 0 || cur_pos == end_pos)
    		percent = 100;
    	else
    		percent = ((float)cur_pos / end_pos) * 100;
    	snprintf(buf + strlen(buf), win_size - strlen(buf),
    	    " %3d%% ", percent);
    
    	/* amount transferred */
    	format_size(buf + strlen(buf), win_size - strlen(buf),
    	    cur_pos);
    	strlcat(buf, " ", win_size);
    
    	/* bandwidth usage */
    	format_rate(buf + strlen(buf), win_size - strlen(buf),
    	    (off_t)bytes_per_second);
    	strlcat(buf, "/s ", win_size);
    
    	/* ETA */
    	if (!transferred)
    		stalled += elapsed;
    	else
    		stalled = 0;
    
    	if (stalled >= STALL_TIME)
    		strlcat(buf, "- stalled -", win_size);
    	else if (bytes_per_second == 0 && bytes_left)
    		strlcat(buf, "  --:-- ETA", win_size);
    	else {
    		if (bytes_left > 0)
    			seconds = bytes_left / bytes_per_second;
    		else
    			seconds = elapsed;
    
    		hours = seconds / 3600;
    		seconds -= hours * 3600;
    		minutes = seconds / 60;
    		seconds -= minutes * 60;
    
    		if (hours != 0)
    			snprintf(buf + strlen(buf), win_size - strlen(buf),
    			    "%d:%02d:%02d", hours, minutes, seconds);
    		else
    			snprintf(buf + strlen(buf), win_size - strlen(buf),
    			    "  %02d:%02d", minutes, seconds);
    
    		if (bytes_left > 0)
    			strlcat(buf, " ETA", win_size);
    		else
    			strlcat(buf, "    ", win_size);
    	}
    
    	atomicio(vwrite, STDOUT_FILENO, buf, win_size - 1);
    	last_update = now;
    }
    
    /*ARGSUSED*/
    static void
    sig_alarm(int ignore)
    {
    	alarm_fired = 1;
    	alarm(UPDATE_INTERVAL);
    }
    
    void
    start_progress_meter(const char *f, off_t filesize, off_t *ctr)
    {
    	start = last_update = monotime_double();
    	file = f;
    	start_pos = *ctr;
    	end_pos = filesize;
    	cur_pos = 0;
    	counter = ctr;
    	stalled = 0;
    	bytes_per_second = 0;
    
    	setscreensize();
    	refresh_progress_meter(1);
    
    	ssh_signal(SIGALRM, sig_alarm);
    	ssh_signal(SIGWINCH, sig_winch);
    	alarm(UPDATE_INTERVAL);
    }
    
    void
    stop_progress_meter(void)
    {
    	alarm(0);
    
    	if (!can_output())
    		return;
    
    	/* Ensure we complete the progress */
    	if (cur_pos != end_pos)
    		refresh_progress_meter(1);
    
    	atomicio(vwrite, STDOUT_FILENO, "\n", 1);
    }
    
    /*ARGSUSED*/
    static void
    sig_winch(int sig)
    {
    	win_resized = 1;
    }
    
    static void
    setscreensize(void)
    {
    	struct winsize winsize;
    
    	if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &winsize) != -1 &&
    	    winsize.ws_col != 0) {
    		if (winsize.ws_col > MAX_WINSIZE)
    			win_size = MAX_WINSIZE;
    		else
    			win_size = winsize.ws_col;
    	} else
    		win_size = DEFAULT_WINSIZE;
    	win_size += 1;					/* trailing \0 */
    }