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-rwxr-xr-xsrc/util.c514
1 files changed, 514 insertions, 0 deletions
diff --git a/src/util.c b/src/util.c
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+++ b/src/util.c
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+/* dnsmasq is Copyright (c) 2000-2009 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, or
+ (at your option) version 3 dated 29 June, 2007.
+
+ 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.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/* The SURF random number generator was taken from djbdns-1.05, by
+ Daniel J Bernstein, which is public domain. */
+
+
+#include "dnsmasq.h"
+
+#ifdef HAVE_BROKEN_RTC
+#include <sys/times.h>
+#endif
+
+#ifdef LOCALEDIR
+#include <idna.h>
+#endif
+
+#ifdef HAVE_ARC4RANDOM
+void rand_init(void)
+{
+ return;
+}
+
+unsigned short rand16(void)
+{
+ return (unsigned short) (arc4random() >> 15);
+}
+
+#else
+
+/* SURF random number generator */
+
+typedef unsigned int uint32;
+
+static uint32 seed[32];
+static uint32 in[12];
+static uint32 out[8];
+
+void rand_init()
+{
+ int fd = open(RANDFILE, O_RDONLY);
+
+ if (fd == -1 ||
+ !read_write(fd, (unsigned char *)&seed, sizeof(seed), 1) ||
+ !read_write(fd, (unsigned char *)&in, sizeof(in), 1))
+ die(_("failed to seed the random number generator: %s"), NULL, EC_MISC);
+
+ close(fd);
+}
+
+#define ROTATE(x,b) (((x) << (b)) | ((x) >> (32 - (b))))
+#define MUSH(i,b) x = t[i] += (((x ^ seed[i]) + sum) ^ ROTATE(x,b));
+
+static void surf(void)
+{
+ uint32 t[12]; uint32 x; uint32 sum = 0;
+ int r; int i; int loop;
+
+ for (i = 0;i < 12;++i) t[i] = in[i] ^ seed[12 + i];
+ for (i = 0;i < 8;++i) out[i] = seed[24 + i];
+ x = t[11];
+ for (loop = 0;loop < 2;++loop) {
+ for (r = 0;r < 16;++r) {
+ sum += 0x9e3779b9;
+ MUSH(0,5) MUSH(1,7) MUSH(2,9) MUSH(3,13)
+ MUSH(4,5) MUSH(5,7) MUSH(6,9) MUSH(7,13)
+ MUSH(8,5) MUSH(9,7) MUSH(10,9) MUSH(11,13)
+ }
+ for (i = 0;i < 8;++i) out[i] ^= t[i + 4];
+ }
+}
+
+unsigned short rand16(void)
+{
+ static int outleft = 0;
+
+ if (!outleft) {
+ if (!++in[0]) if (!++in[1]) if (!++in[2]) ++in[3];
+ surf();
+ outleft = 8;
+ }
+
+ return (unsigned short) out[--outleft];
+}
+
+#endif
+
+static int check_name(char *in)
+{
+ /* remove trailing .
+ also fail empty string and label > 63 chars */
+ size_t dotgap = 0, l = strlen(in);
+ char c;
+ int nowhite = 0;
+
+ if (l == 0 || l > MAXDNAME) return 0;
+
+ if (in[l-1] == '.')
+ {
+ if (l == 1) return 0;
+ in[l-1] = 0;
+ }
+
+ for (; (c = *in); in++)
+ {
+ if (c == '.')
+ dotgap = 0;
+ else if (++dotgap > MAXLABEL)
+ return 0;
+ else if (isascii(c) && iscntrl(c))
+ /* iscntrl only gives expected results for ascii */
+ return 0;
+#ifndef LOCALEDIR
+ else if (!isascii(c))
+ return 0;
+#endif
+ else if (c != ' ')
+ nowhite = 1;
+ }
+
+ if (!nowhite)
+ return 0;
+
+ return 1;
+}
+
+/* Hostnames have a more limited valid charset than domain names
+ so check for legal char a-z A-Z 0-9 - _
+ Note that this may receive a FQDN, so only check the first label
+ for the tighter criteria. */
+int legal_hostname(char *name)
+{
+ char c;
+
+ if (!check_name(name))
+ return 0;
+
+ for (; (c = *name); name++)
+ /* check for legal char a-z A-Z 0-9 - _ . */
+ {
+ if ((c >= 'A' && c <= 'Z') ||
+ (c >= 'a' && c <= 'z') ||
+ (c >= '0' && c <= '9') ||
+ c == '-' || c == '_')
+ continue;
+
+ /* end of hostname part */
+ if (c == '.')
+ return 1;
+
+ return 0;
+ }
+
+ return 1;
+}
+
+char *canonicalise(char *in, int *nomem)
+{
+ char *ret = NULL;
+#ifdef LOCALEDIR
+ int rc;
+#endif
+
+ if (nomem)
+ *nomem = 0;
+
+ if (!check_name(in))
+ return NULL;
+
+#ifdef LOCALEDIR
+ if ((rc = idna_to_ascii_lz(in, &ret, 0)) != IDNA_SUCCESS)
+ {
+ if (ret)
+ free(ret);
+
+ if (nomem && (rc == IDNA_MALLOC_ERROR || rc == IDNA_DLOPEN_ERROR))
+ {
+ my_syslog(LOG_ERR, _("failed to allocate memory"));
+ *nomem = 1;
+ }
+
+ return NULL;
+ }
+#else
+ if ((ret = whine_malloc(strlen(in)+1)))
+ strcpy(ret, in);
+ else if (nomem)
+ *nomem = 1;
+#endif
+
+ return ret;
+}
+
+unsigned char *do_rfc1035_name(unsigned char *p, char *sval)
+{
+ int j;
+
+ while (sval && *sval)
+ {
+ unsigned char *cp = p++;
+ for (j = 0; *sval && (*sval != '.'); sval++, j++)
+ *p++ = *sval;
+ *cp = j;
+ if (*sval)
+ sval++;
+ }
+ return p;
+}
+
+/* for use during startup */
+void *safe_malloc(size_t size)
+{
+ void *ret = malloc(size);
+
+ if (!ret)
+ die(_("could not get memory"), NULL, EC_NOMEM);
+
+ return ret;
+}
+
+void safe_pipe(int *fd, int read_noblock)
+{
+ if (pipe(fd) == -1 ||
+ !fix_fd(fd[1]) ||
+ (read_noblock && !fix_fd(fd[0])))
+ die(_("cannot create pipe: %s"), NULL, EC_MISC);
+}
+
+void *whine_malloc(size_t size)
+{
+ void *ret = malloc(size);
+
+ if (!ret)
+ my_syslog(LOG_ERR, _("failed to allocate %d bytes"), (int) size);
+
+ return ret;
+}
+
+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 &&
+ s1->in.sin_addr.s_addr == s2->in.sin_addr.s_addr)
+ return 1;
+#ifdef HAVE_IPV6
+ if (s1->sa.sa_family == AF_INET6 &&
+ s1->in6.sin6_port == s2->in6.sin6_port &&
+ IN6_ARE_ADDR_EQUAL(&s1->in6.sin6_addr, &s2->in6.sin6_addr))
+ 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(char *a, char *b)
+{
+ unsigned int c1, c2;
+
+ do {
+ c1 = (unsigned char) *a++;
+ c2 = (unsigned char) *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(void)
+{
+#ifdef HAVE_BROKEN_RTC
+ struct tms dummy;
+ static long tps = 0;
+
+ if (tps == 0)
+ tps = sysconf(_SC_CLK_TCK);
+
+ return (time_t)(times(&dummy)/tps);
+#else
+ 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);
+}
+
+/* returns port number from address */
+int prettyprint_addr(union mysockaddr *addr, char *buf)
+{
+ int port = 0;
+
+#ifdef HAVE_IPV6
+ if (addr->sa.sa_family == AF_INET)
+ {
+ inet_ntop(AF_INET, &addr->in.sin_addr, buf, ADDRSTRLEN);
+ port = ntohs(addr->in.sin_port);
+ }
+ else if (addr->sa.sa_family == AF_INET6)
+ {
+ inet_ntop(AF_INET6, &addr->in6.sin6_addr, buf, ADDRSTRLEN);
+ port = ntohs(addr->in6.sin6_port);
+ }
+#else
+ strcpy(buf, inet_ntoa(addr->in.sin_addr));
+ port = ntohs(addr->in.sin_port);
+#endif
+
+ return port;
+}
+
+void prettyprint_time(char *buf, unsigned int t)
+{
+ if (t == 0xffffffff)
+ sprintf(buf, _("infinite"));
+ else
+ {
+ unsigned int x, p = 0;
+ if ((x = t/86400))
+ p += sprintf(&buf[p], "%dd", x);
+ if ((x = (t/3600)%24))
+ 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 *mac_type)
+{
+ int mask = 0, i = 0;
+ char *r;
+
+ if (mac_type)
+ *mac_type = 0;
+
+ while (maxlen == -1 || i < maxlen)
+ {
+ for (r = in; *r != 0 && *r != ':' && *r != '-'; r++);
+ if (*r == 0)
+ maxlen = i;
+
+ if (r != in )
+ {
+ if (*r == '-' && i == 0 && mac_type)
+ {
+ *r = 0;
+ *mac_type = strtol(in, NULL, 16);
+ mac_type = NULL;
+ }
+ else
+ {
+ *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;
+}
+
+/* return 0 for no match, or (no matched octets) + 1 */
+int memcmp_masked(unsigned char *a, unsigned char *b, int len, unsigned int mask)
+{
+ int i, count;
+ for (count = 1, i = len - 1; i >= 0; i--, mask = mask >> 1)
+ if (!(mask & 1))
+ {
+ if (a[i] == b[i])
+ count++;
+ else
+ return 0;
+ }
+ return count;
+}
+
+/* _note_ may copy buffer */
+int expand_buf(struct iovec *iov, size_t size)
+{
+ void *new;
+
+ if (size <= (size_t)iov->iov_len)
+ return 1;
+
+ if (!(new = whine_malloc(size)))
+ {
+ errno = ENOMEM;
+ return 0;
+ }
+
+ if (iov->iov_base)
+ {
+ memcpy(new, iov->iov_base, iov->iov_len);
+ free(iov->iov_base);
+ }
+
+ iov->iov_base = new;
+ iov->iov_len = size;
+
+ return 1;
+}
+
+char *print_mac(char *buff, unsigned char *mac, int len)
+{
+ char *p = buff;
+ int i;
+
+ if (len == 0)
+ sprintf(p, "<null>");
+ else
+ for (i = 0; i < len; i++)
+ p += sprintf(p, "%.2x%s", mac[i], (i == len - 1) ? "" : ":");
+
+ return buff;
+}
+
+void bump_maxfd(int fd, int *max)
+{
+ if (fd > *max)
+ *max = fd;
+}
+
+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;
+}
+
+int read_write(int fd, unsigned char *packet, int size, int rw)
+{
+ ssize_t n, done;
+
+ for (done = 0; done < size; done += n)
+ {
+ retry:
+ if (rw)
+ n = read(fd, &packet[done], (size_t)(size - done));
+ else
+ n = write(fd, &packet[done], (size_t)(size - done));
+
+ if (n == 0)
+ return 0;
+ else if (n == -1)
+ {
+ if (retry_send() || errno == ENOMEM || errno == ENOBUFS)
+ goto retry;
+ else
+ return 0;
+ }
+ }
+ return 1;
+}
+
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