| /* |
| * tc_core.c TC core library. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| * |
| * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> |
| * |
| */ |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| #include <syslog.h> |
| #include <fcntl.h> |
| #include <math.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <string.h> |
| |
| #include "tc_core.h" |
| |
| static double tick_in_usec = 1; |
| static double clock_factor = 1; |
| |
| int tc_core_time2big(unsigned time) |
| { |
| __u64 t = time; |
| |
| t *= tick_in_usec; |
| return (t >> 32) != 0; |
| } |
| |
| |
| unsigned tc_core_time2tick(unsigned time) |
| { |
| return time*tick_in_usec; |
| } |
| |
| unsigned tc_core_tick2time(unsigned tick) |
| { |
| return tick/tick_in_usec; |
| } |
| |
| unsigned tc_core_time2ktime(unsigned time) |
| { |
| return time * clock_factor; |
| } |
| |
| unsigned tc_core_ktime2time(unsigned ktime) |
| { |
| return ktime / clock_factor; |
| } |
| |
| unsigned tc_calc_xmittime(unsigned rate, unsigned size) |
| { |
| return tc_core_time2tick(TIME_UNITS_PER_SEC*((double)size/rate)); |
| } |
| |
| unsigned tc_calc_xmitsize(unsigned rate, unsigned ticks) |
| { |
| return ((double)rate*tc_core_tick2time(ticks))/TIME_UNITS_PER_SEC; |
| } |
| |
| /* |
| rtab[pkt_len>>cell_log] = pkt_xmit_time |
| */ |
| |
| int tc_calc_rtable(unsigned bps, __u32 *rtab, int cell_log, unsigned mtu, |
| unsigned mpu) |
| { |
| int i; |
| unsigned overhead = (mpu >> 8) & 0xFF; |
| mpu = mpu & 0xFF; |
| |
| if (mtu == 0) |
| mtu = 2047; |
| |
| if (cell_log < 0) { |
| cell_log = 0; |
| while ((mtu>>cell_log) > 255) |
| cell_log++; |
| } |
| for (i=0; i<256; i++) { |
| unsigned sz = (i<<cell_log); |
| if (overhead) |
| sz += overhead; |
| if (sz < mpu) |
| sz = mpu; |
| rtab[i] = tc_calc_xmittime(bps, sz); |
| } |
| return cell_log; |
| } |
| |
| int tc_core_init() |
| { |
| FILE *fp; |
| __u32 clock_res; |
| __u32 t2us; |
| __u32 us2t; |
| |
| fp = fopen("/proc/net/psched", "r"); |
| if (fp == NULL) |
| return -1; |
| |
| if (fscanf(fp, "%08x%08x%08x", &t2us, &us2t, &clock_res) != 3) { |
| fclose(fp); |
| return -1; |
| } |
| fclose(fp); |
| |
| /* compatibility hack: for old iproute binaries (ignoring |
| * the kernel clock resolution) the kernel advertises a |
| * tick multiplier of 1000 in case of nano-second resolution, |
| * which really is 1. */ |
| if (clock_res == 1000000000) |
| t2us = us2t; |
| |
| clock_factor = (double)clock_res / TIME_UNITS_PER_SEC; |
| tick_in_usec = (double)t2us / us2t * clock_factor; |
| return 0; |
| } |