blob: d71c1ec921e08b653f04ecf800886c6f733ef16a [file] [log] [blame]
/* dnsmasq is Copyright (c) 2000 - 2005 Simon Kelley
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; version 2 dated June, 1991.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
*/
/* Some code in this file contributed by Rob Funk. */
#include "dnsmasq.h"
/* Prefer arc4random(3) over random(3) over rand(3) */
/* Also prefer /dev/urandom over /dev/random, to preserve the entropy pool */
#ifdef HAVE_ARC4RANDOM
# define rand() arc4random()
# define srand(s) (void)0
# define RANDFILE (NULL)
#else
# ifdef HAVE_RANDOM
# define rand() random()
# define srand(s) srandom(s)
# endif
# ifdef HAVE_DEV_URANDOM
# define RANDFILE "/dev/urandom"
# else
# ifdef HAVE_DEV_RANDOM
# define RANDFILE "/dev/random"
# else
# define RANDFILE (NULL)
# endif
# endif
#endif
unsigned short rand16(void)
{
static int been_seeded = 0;
const char *randfile = RANDFILE;
if (! been_seeded)
{
int fd, n = 0;
unsigned int c = 0, seed = 0, badseed;
char sbuf[sizeof(seed)];
char *s;
struct timeval now;
/* get the bad seed as a backup */
/* (but we'd rather have something more random) */
gettimeofday(&now, NULL);
badseed = now.tv_sec ^ now.tv_usec ^ (getpid() << 16);
fd = open(randfile, O_RDONLY);
if (fd < 0)
seed = badseed;
else
{
s = (char *) &seed;
while ((c < sizeof(seed)) &&
((n = read(fd, sbuf, sizeof(seed)) > 0)))
{
memcpy(s, sbuf, n);
s += n;
c += n;
}
if (n < 0)
seed = badseed;
close(fd);
}
srand(seed);
been_seeded = 1;
}
/* Some rand() implementations have less randomness in low bits
* than in high bits, so we only pay attention to the high ones.
* But most implementations don't touch the high bit, so we
* ignore that one.
*/
return( (unsigned short) (rand() >> 15) );
}
int atoi_check(char *a, int *res)
{
char *p;
for (p = a; *p; p++)
if (*p < '0' || *p > '9')
return 0;
*res = atoi(a);
return 1;
}
int legal_char(char c)
{
/* check for legal char a-z A-Z 0-9 -
(also / , used for RFC2317 and _ used in windows queries) */
if ((c >= 'A' && c <= 'Z') ||
(c >= 'a' && c <= 'z') ||
(c >= '0' && c <= '9') ||
c == '-' || c == '/' || c == '_')
return 1;
return 0;
}
int canonicalise(char *s)
{
/* check for legal chars and remove trailing .
also fail empty string and label > 63 chars */
size_t dotgap = 0, l = strlen(s);
char c;
if (l == 0 || l > MAXDNAME) return 0;
if (s[l-1] == '.')
{
if (l == 1) return 0;
s[l-1] = 0;
}
while ((c = *s++))
if (c == '.')
dotgap = 0;
else if (!legal_char(c) || (++dotgap > MAXLABEL))
return 0;
return 1;
}
/* for use during startup */
void *safe_malloc(size_t size)
{
void *ret = malloc(size);
if (!ret)
die("could not get memory", NULL);
return ret;
}
char *safe_string_alloc(char *cp)
{
char *ret = NULL;
if (cp && strlen(cp) != 0)
{
ret = safe_malloc(strlen(cp)+1);
strcpy(ret, cp);
}
return ret;
}
static void log_err(char *message, char *arg1)
{
char *errmess = strerror(errno);
if (!arg1)
arg1 = errmess;
fprintf(stderr, "dnsmasq: ");
fprintf(stderr, message, arg1, errmess);
fprintf(stderr, "\n");
syslog(LOG_CRIT, message, arg1, errmess);
}
void complain(char *message, int lineno, char *file)
{
char buff[256];
sprintf(buff, "%s at line %d of %s", message, lineno, file);
log_err(buff, NULL);
}
void die(char *message, char *arg1)
{
log_err(message, arg1);
syslog(LOG_CRIT, "FAILED to start up");
exit(1);
}
int sockaddr_isequal(union mysockaddr *s1, union mysockaddr *s2)
{
if (s1->sa.sa_family == s2->sa.sa_family)
{
if (s1->sa.sa_family == AF_INET &&
s1->in.sin_port == s2->in.sin_port &&
memcmp(&s1->in.sin_addr, &s2->in.sin_addr, sizeof(struct in_addr)) == 0)
return 1;
#ifdef HAVE_IPV6
if (s1->sa.sa_family == AF_INET6 &&
s1->in6.sin6_port == s2->in6.sin6_port &&
s1->in6.sin6_flowinfo == s2->in6.sin6_flowinfo &&
memcmp(&s1->in6.sin6_addr, &s2->in6.sin6_addr, sizeof(struct in6_addr)) == 0)
return 1;
#endif
}
return 0;
}
int sa_len(union mysockaddr *addr)
{
#ifdef HAVE_SOCKADDR_SA_LEN
return addr->sa.sa_len;
#else
#ifdef HAVE_IPV6
if (addr->sa.sa_family == AF_INET6)
return sizeof(addr->in6);
else
#endif
return sizeof(addr->in);
#endif
}
/* don't use strcasecmp and friends here - they may be messed up by LOCALE */
int hostname_isequal(unsigned char *a, unsigned char *b)
{
unsigned int c1, c2;
do {
c1 = *a++;
c2 = *b++;
if (c1 >= 'A' && c1 <= 'Z')
c1 += 'a' - 'A';
if (c2 >= 'A' && c2 <= 'Z')
c2 += 'a' - 'A';
if (c1 != c2)
return 0;
} while (c1);
return 1;
}
time_t dnsmasq_time(int fd)
{
#ifdef HAVE_BROKEN_RTC
/* we use uptime as a time-base, rather than epoch time
because epoch time can break when a machine contacts
a nameserver and updates it. */
char buf[30];
lseek(fd, 0, SEEK_SET);
read(fd, buf, 30);
return (time_t)atol(buf);
#else
fd = 0; /* stop warning */
return time(NULL);
#endif
}
int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask)
{
return (a.s_addr & mask.s_addr) == (b.s_addr & mask.s_addr);
}
int retry_send(void)
{
struct timespec waiter;
if (errno == EAGAIN)
{
waiter.tv_sec = 0;
waiter.tv_nsec = 10000;
nanosleep(&waiter, NULL);
return 1;
}
if (errno == EINTR)
return 1;
return 0;
}
void prettyprint_time(char *buf, unsigned int t)
{
if (t == 0xffffffff)
sprintf(buf, "infinite");
else
{
unsigned int x, p = 0;
if ((x = t/3600))
p += sprintf(&buf[p], "%dh", x);
if ((x = (t/60)%60))
p += sprintf(&buf[p], "%dm", x);
if ((x = t%60))
p += sprintf(&buf[p], "%ds", x);
}
}
/* in may equal out, when maxlen may be -1 (No max len). */
int parse_hex(char *in, unsigned char *out, int maxlen, unsigned int *wildcard_mask)
{
int mask = 0, i = 0;
char *r;
while (maxlen == -1 || i < maxlen)
{
for (r = in; *r != 0 && *r != ':' && *r != '-'; r++);
if (*r == 0)
maxlen = i;
if (r != in )
{
*r = 0;
mask = mask << 1;
if (strcmp(in, "*") == 0)
mask |= 1;
else
out[i] = strtol(in, NULL, 16);
i++;
}
in = r+1;
}
if (wildcard_mask)
*wildcard_mask = mask;
return i;
}