kernel.c 3 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
/*
Copyright 2007, 2008 by Grégoire Henry, Julien Cristau and Juliusz Chroboczek

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
*/

23
#include <sys/time.h>
24
#include <sys/param.h>
25
#include <time.h>
Juliusz Chroboczek's avatar
Juliusz Chroboczek committed
26

27
#include "babeld.h"
28

dermiste's avatar
dermiste committed
29
#ifdef __linux
30
#include "kernel_netlink.c"
dermiste's avatar
dermiste committed
31 32
#else
#include "kernel_socket.c"
33
#endif
34

35 36 37
int src_table_idx = 10;
int src_table_prio = 100;

Juliusz Chroboczek's avatar
Juliusz Chroboczek committed
38 39
/* Like gettimeofday, but returns monotonic time.  If POSIX clocks are not
   available, falls back to gettimeofday but enforces monotonicity. */
40 41 42
int
gettime(struct timeval *tv)
{
Juliusz Chroboczek's avatar
Juliusz Chroboczek committed
43 44 45
    int rc;
    static time_t offset = 0, previous = 0;

46 47 48
#if defined(_POSIX_TIMERS) && _POSIX_TIMERS > 0 && defined(CLOCK_MONOTONIC)
    static int have_posix_clocks = -1;

49
    if(UNLIKELY(have_posix_clocks < 0)) {
50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70
        struct timespec ts;
        rc = clock_gettime(CLOCK_MONOTONIC, &ts);
        if(rc < 0) {
            have_posix_clocks = 0;
        } else {
            have_posix_clocks = 1;
        }
    }

    if(have_posix_clocks) {
        struct timespec ts;
        int rc;
        rc = clock_gettime(CLOCK_MONOTONIC, &ts);
        if(rc < 0)
            return rc;
        tv->tv_sec = ts.tv_sec;
        tv->tv_usec = ts.tv_nsec / 1000;
        return rc;
    }
#endif

Juliusz Chroboczek's avatar
Juliusz Chroboczek committed
71 72 73 74 75 76 77 78 79 80
    rc = gettimeofday(tv, NULL);
    if(rc < 0)
        return rc;
    tv->tv_sec += offset;
    if(UNLIKELY(previous > tv->tv_sec)) {
        offset += previous - tv->tv_sec;
        tv->tv_sec = previous;
    }
    previous = tv->tv_sec;
    return rc;
81
}
dermiste's avatar
dermiste committed
82

83 84
/* If /dev/urandom doesn't exist, this will fail with ENOENT, which the
   caller will deal with gracefully. */
dermiste's avatar
dermiste committed
85 86 87 88

int
read_random_bytes(void *buf, size_t len)
{
89
    int fd;
dermiste's avatar
dermiste committed
90 91
    int rc;

92 93
    fd = open("/dev/urandom", O_RDONLY);
    if(fd < 0) {
94
        rc = -1;
dermiste's avatar
dermiste committed
95
    } else {
96
        rc = read(fd, buf, len);
97
        if(rc < 0 || (unsigned)rc < len)
dermiste's avatar
dermiste committed
98
            rc = -1;
99
        close(fd);
dermiste's avatar
dermiste committed
100 101 102 103
    }
    return rc;
}

104 105 106 107 108 109 110 111
int
add_import_table(int table)
{
    if(table < 0 || table > 0xFFFF) return -1;
    if(import_table_count > MAX_IMPORT_TABLES - 1) return -2;
    import_tables[import_table_count++] = table;
    return 0;
}