utils.c

/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Utility functions
 *
 * Copyright (C)  2004 - 2005, Digium, Inc.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License
 */

#include <ctype.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdarg.h>

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/lock.h"
#include "asterisk/io.h"
#include "asterisk/logger.h"
#include "asterisk/md5.h"
#include "asterisk/options.h"

#define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/strings.h"

#define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/time.h"

#define AST_API_MODULE		/* ensure that inlinable API functions will be built in this module if required */
#include "asterisk/utils.h"

static char base64[64];
static char b2a[256];

#if defined(__FreeBSD__) || defined(__OpenBSD__) || defined( __NetBSD__ ) || defined(__APPLE__)

/* duh? ERANGE value copied from web... */
#define ERANGE 34
#undef gethostbyname

AST_MUTEX_DEFINE_STATIC(__mutex);

/* Recursive replacement for gethostbyname for BSD-based systems.  This
routine is derived from code originally written and placed in the public 
domain by Enzo Michelangeli <em@em.no-ip.com> */

static int gethostbyname_r (const char *name, struct hostent *ret, char *buf,
				size_t buflen, struct hostent **result, 
				int *h_errnop) 
{
	int hsave;
	struct hostent *ph;
	ast_mutex_lock(&__mutex); /* begin critical area */
	hsave = h_errno;

	ph = gethostbyname(name);
	*h_errnop = h_errno; /* copy h_errno to *h_herrnop */
	if (ph == NULL) {
		*result = NULL;
	} else {
		char **p, **q;
		char *pbuf;
		int nbytes=0;
		int naddr=0, naliases=0;
		/* determine if we have enough space in buf */

		/* count how many addresses */
		for (p = ph->h_addr_list; *p != 0; p++) {
			nbytes += ph->h_length; /* addresses */
			nbytes += sizeof(*p); /* pointers */
			naddr++;
		}
		nbytes += sizeof(*p); /* one more for the terminating NULL */

		/* count how many aliases, and total length of strings */
		for (p = ph->h_aliases; *p != 0; p++) {
			nbytes += (strlen(*p)+1); /* aliases */
			nbytes += sizeof(*p);  /* pointers */
			naliases++;
		}
		nbytes += sizeof(*p); /* one more for the terminating NULL */

		/* here nbytes is the number of bytes required in buffer */
		/* as a terminator must be there, the minimum value is ph->h_length */
		if(nbytes > buflen) {
			*result = NULL;
			ast_mutex_unlock(&__mutex); /* end critical area */
			return ERANGE; /* not enough space in buf!! */
		}

		/* There is enough space. Now we need to do a deep copy! */
		/* Allocation in buffer:
			from [0] to [(naddr-1) * sizeof(*p)]:
			pointers to addresses
			at [naddr * sizeof(*p)]:
			NULL
			from [(naddr+1) * sizeof(*p)] to [(naddr+naliases) * sizeof(*p)] :
			pointers to aliases
			at [(naddr+naliases+1) * sizeof(*p)]:
			NULL
			then naddr addresses (fixed length), and naliases aliases (asciiz).
		*/

		*ret = *ph;   /* copy whole structure (not its address!) */

		/* copy addresses */
		q = (char **)buf; /* pointer to pointers area (type: char **) */
		ret->h_addr_list = q; /* update pointer to address list */
		pbuf = buf + ((naddr+naliases+2)*sizeof(*p)); /* skip that area */
		for (p = ph->h_addr_list; *p != 0; p++) {
			memcpy(pbuf, *p, ph->h_length); /* copy address bytes */
			*q++ = pbuf; /* the pointer is the one inside buf... */
			pbuf += ph->h_length; /* advance pbuf */
		}
		*q++ = NULL; /* address list terminator */

		/* copy aliases */
		ret->h_aliases = q; /* update pointer to aliases list */
		for (p = ph->h_aliases; *p != 0; p++) {
			strcpy(pbuf, *p); /* copy alias strings */
			*q++ = pbuf; /* the pointer is the one inside buf... */
			pbuf += strlen(*p); /* advance pbuf */
			*pbuf++ = 0; /* string terminator */
		}
		*q++ = NULL; /* terminator */

		strcpy(pbuf, ph->h_name); /* copy alias strings */
		ret->h_name = pbuf;
		pbuf += strlen(ph->h_name); /* advance pbuf */
		*pbuf++ = 0; /* string terminator */

		*result = ret;  /* and let *result point to structure */

	}
	h_errno = hsave;  /* restore h_errno */
	ast_mutex_unlock(&__mutex); /* end critical area */

	return (*result == NULL); /* return 0 on success, non-zero on error */
}


#endif

/* Re-entrant (thread safe) version of gethostbyname that replaces the 
   standard gethostbyname (which is not thread safe)
*/
struct hostent *ast_gethostbyname(const char *host, struct ast_hostent *hp)
{
	int res;
	int herrno;
	const char *s;
	struct hostent *result = NULL;
	/* Although it is perfectly legitimate to lookup a pure integer, for
	   the sake of the sanity of people who like to name their peers as
	   integers, we break with tradition and refuse to look up a
	   pure integer */
	s = host;
	res = 0;
	while(s && *s) {
		if (!isdigit(*s))
			break;
		s++;
	}
	if (!s || !*s)
		return NULL;
#ifdef SOLARIS
	result = gethostbyname_r(host, &hp->hp, hp->buf, sizeof(hp->buf), &herrno);

	if (!result || !hp->hp.h_addr_list || !hp->hp.h_addr_list[0])
		return NULL;
#else
	res = gethostbyname_r(host, &hp->hp, hp->buf, sizeof(hp->buf), &result, &herrno);

	if (res || !result || !hp->hp.h_addr_list || !hp->hp.h_addr_list[0])
		return NULL;
#endif
	return &hp->hp;
}


/* This is a regression test for recursive mutexes.
   test_for_thread_safety() will return 0 if recursive mutex locks are
   working properly, and non-zero if they are not working properly. */

AST_MUTEX_DEFINE_STATIC(test_lock);
AST_MUTEX_DEFINE_STATIC(test_lock2);
static pthread_t test_thread; 
static int lock_count = 0;
static int test_errors = 0;

static void *test_thread_body(void *data) 
{ 
	ast_mutex_lock(&test_lock);
	lock_count += 10;
	if (lock_count != 10) 
		test_errors++;
	ast_mutex_lock(&test_lock);
	lock_count += 10;
	if (lock_count != 20) 
		test_errors++;
	ast_mutex_lock(&test_lock2);
	ast_mutex_unlock(&test_lock);
	lock_count -= 10;
	if (lock_count != 10) 
		test_errors++;
	ast_mutex_unlock(&test_lock);
	lock_count -= 10;
	ast_mutex_unlock(&test_lock2);
	if (lock_count != 0) 
		test_errors++;
	return NULL;
} 

int test_for_thread_safety(void)
{ 
	ast_mutex_lock(&test_lock2);
	ast_mutex_lock(&test_lock);
	lock_count += 1;
	ast_mutex_lock(&test_lock);
	lock_count += 1;
	ast_pthread_create(&test_thread, NULL, test_thread_body, NULL); 
	usleep(100);
	if (lock_count != 2) 
		test_errors++;
	ast_mutex_unlock(&test_lock);
	lock_count -= 1;
	usleep(100); 
	if (lock_count != 1) 
		test_errors++;
	ast_mutex_unlock(&test_lock);
	lock_count -= 1;
	if (lock_count != 0) 
		test_errors++;
	ast_mutex_unlock(&test_lock2);
	usleep(100);
	if (lock_count != 0) 
		test_errors++;
	pthread_join(test_thread, NULL);
	return(test_errors);          /* return 0 on success. */
}

/*--- ast_md5_hash: Produce 16 char MD5 hash of value. ---*/
void ast_md5_hash(char *output, char *input)
{
	struct MD5Context md5;
	unsigned char digest[16];
	char *ptr;
	int x;

	MD5Init(&md5);
	MD5Update(&md5, (unsigned char *)input, strlen(input));
	MD5Final(digest, &md5);
	ptr = output;
	for (x=0; x<16; x++)
		ptr += sprintf(ptr, "%2.2x", digest[x]);
}

int ast_base64decode(unsigned char *dst, char *src, int max)
{
	int cnt = 0;
	unsigned int byte = 0;
	unsigned int bits = 0;
	int incnt = 0;
#if 0
	unsigned char *odst = dst;
#endif
	while(*src && (cnt < max)) {
		/* Shift in 6 bits of input */
		byte <<= 6;
		byte |= (b2a[(int)(*src)]) & 0x3f;
		bits += 6;
#if 0
		printf("Add: %c %s\n", *src, binary(b2a[(int)(*src)] & 0x3f, 6));
#endif
		src++;
		incnt++;
		/* If we have at least 8 bits left over, take that character 
		   off the top */
		if (bits >= 8)  {
			bits -= 8;
			*dst = (byte >> bits) & 0xff;
#if 0
			printf("Remove: %02x %s\n", *dst, binary(*dst, 8));
#endif
			dst++;
			cnt++;
		}
	}
#if 0
	dump(odst, cnt);
#endif
	/* Dont worry about left over bits, they're extra anyway */
	return cnt;
}

int ast_base64encode(char *dst, unsigned char *src, int srclen, int max)
{
	int cnt = 0;
	unsigned int byte = 0;
	int bits = 0;
	int index;
	int cntin = 0;
#if 0
	char *odst = dst;
	dump(src, srclen);
#endif
	/* Reserve one bit for end */
	max--;
	while((cntin < srclen) && (cnt < max)) {
		byte <<= 8;
#if 0
		printf("Add: %02x %s\n", *src, binary(*src, 8));
#endif
		byte |= *(src++);
		bits += 8;
		cntin++;
		while((bits >= 6) && (cnt < max)) {
			bits -= 6;
			/* We want only the top */
			index = (byte >> bits) & 0x3f;
			*dst = base64[index];
#if 0
			printf("Remove: %c %s\n", *dst, binary(index, 6));
#endif
			dst++;
			cnt++;
		}
	}
	if (bits && (cnt < max)) {
		/* Add one last character for the remaining bits, 
		   padding the rest with 0 */
		byte <<= (6 - bits);
		index = (byte) & 0x3f;
		*(dst++) = base64[index];
		cnt++;
	}
	*dst = '\0';
	return cnt;
}

static void base64_init(void)
{
	int x;
	memset(b2a, -1, sizeof(b2a));
	/* Initialize base-64 Conversion table */
	for (x=0;x<26;x++) {
		/* A-Z */
		base64[x] = 'A' + x;
		b2a['A' + x] = x;
		/* a-z */
		base64[x + 26] = 'a' + x;
		b2a['a' + x] = x + 26;
		/* 0-9 */
		if (x < 10) {
			base64[x + 52] = '0' + x;
			b2a['0' + x] = x + 52;
		}
	}
	base64[62] = '+';
	base64[63] = '/';
	b2a[(int)'+'] = 62;
	b2a[(int)'/'] = 63;
#if 0
	for (x=0;x<64;x++) {
		if (b2a[(int)base64[x]] != x) {
			fprintf(stderr, "!!! %d failed\n", x);
		} else
			fprintf(stderr, "--- %d passed\n", x);
	}
#endif
}

/* Recursive thread safe replacement of inet_ntoa */
const char *ast_inet_ntoa(char *buf, int bufsiz, struct in_addr ia)
{
	return inet_ntop(AF_INET, &ia, buf, bufsiz);
}

int ast_utils_init(void)
{
	base64_init();
	return 0;
}

#ifndef __linux__
#undef pthread_create /* For ast_pthread_create function only */
#endif /* ! LINUX */
int ast_pthread_create_stack(pthread_t *thread, pthread_attr_t *attr, void *(*start_routine)(void *), void *data, size_t stacksize)
{
	pthread_attr_t lattr;
	if (!attr) {
		pthread_attr_init(&lattr);
		attr = &lattr;
	}
	if (!stacksize)
		stacksize = AST_STACKSIZE;
	errno = pthread_attr_setstacksize(attr, stacksize);
	if (errno)
		ast_log(LOG_WARNING, "pthread_attr_setstacksize returned non-zero: %s\n", strerror(errno));
	return pthread_create(thread, attr, start_routine, data); /* We're in ast_pthread_create, so it's okay */
}

int ast_wait_for_input(int fd, int ms)
{
	struct pollfd pfd[1];
	memset(pfd, 0, sizeof(pfd));
	pfd[0].fd = fd;
	pfd[0].events = POLLIN|POLLPRI;
	return poll(pfd, 1, ms);
}

char *ast_strip_quoted(char *s, const char *beg_quotes, const char *end_quotes)
{
	char *e;
	char *q;

	s = ast_strip(s);
	if ((q = strchr(beg_quotes, *s))) {
		e = s + strlen(s) - 1;
		if (*e == *(end_quotes + (q - beg_quotes))) {
			s++;
			*e = '\0';
		}
	}

	return s;
}

int ast_build_string(char **buffer, size_t *space, const char *fmt, ...)
{
	va_list ap;
	int result;

	if (!buffer || !*buffer || !space || !*space)
		return -1;

	va_start(ap, fmt);
	result = vsnprintf(*buffer, *space, fmt, ap);
	va_end(ap);

	if (result < 0)
		return -1;
	else if (result > *space)
		result = *space;

	*buffer += result;
	*space -= result;
	return 0;
}

int ast_true(const char *s)
{
	if (!s || ast_strlen_zero(s))
		return 0;

	/* Determine if this is a true value */
	if (!strcasecmp(s, "yes") ||
	    !strcasecmp(s, "true") ||
	    !strcasecmp(s, "y") ||
	    !strcasecmp(s, "t") ||
	    !strcasecmp(s, "1") ||
	    !strcasecmp(s, "on"))
		return -1;

	return 0;
}

int ast_false(const char *s)
{
	if (!s || ast_strlen_zero(s))
		return 0;

	/* Determine if this is a false value */
	if (!strcasecmp(s, "no") ||
	    !strcasecmp(s, "false") ||
	    !strcasecmp(s, "n") ||
	    !strcasecmp(s, "f") ||
	    !strcasecmp(s, "0") ||
	    !strcasecmp(s, "off"))
		return -1;

	return 0;
}

#define ONE_MILLION	1000000
/*
 * put timeval in a valid range. usec is 0..999999
 * negative values are not allowed and truncated.
 */
static struct timeval tvfix(struct timeval a)
{
	if (a.tv_usec >= ONE_MILLION) {
		ast_log(LOG_ERROR, "warning too large timestamp %ld.%ld\n",
			a.tv_sec, a.tv_usec);
		a.tv_sec += a.tv_usec % ONE_MILLION;
		a.tv_usec %= ONE_MILLION;
	} else if (a.tv_usec < 0) {
		ast_log(LOG_WARNING, "warning negative timestamp %ld.%ld\n",
				a.tv_sec, a.tv_usec);
		a.tv_usec = 0;
	}
	return a;
}

struct timeval ast_tvadd(struct timeval a, struct timeval b)
{
	/* consistency checks to guarantee usec in 0..999999 */
	a = tvfix(a);
	b = tvfix(b);
	a.tv_sec += b.tv_sec;
	a.tv_usec += b.tv_usec;
	if (a.tv_usec >= ONE_MILLION) {
		a.tv_sec++;
		a.tv_usec -= ONE_MILLION;
	}
	return a;
}

struct timeval ast_tvsub(struct timeval a, struct timeval b)
{
	/* consistency checks to guarantee usec in 0..999999 */
	a = tvfix(a);
	b = tvfix(b);
	a.tv_sec -= b.tv_sec;
	a.tv_usec -= b.tv_usec;
	if (a.tv_usec < 0) {
		a.tv_sec-- ;
		a.tv_usec += ONE_MILLION;
	}
	return a;
}
#undef ONE_MILLION

#ifndef HAVE_STRCASESTR
static char *upper(const char *orig, char *buf, int bufsize)
{
	int i = 0;

	while (i < (bufsize - 1) && orig[i]) {
		buf[i] = toupper(orig[i]);
		i++;
	}

	buf[i] = '\0';

	return buf;
}

char *strcasestr(const char *haystack, const char *needle)
{
	char *u1, *u2;
	int u1len = strlen(haystack) + 1, u2len = strlen(needle) + 1;

	u1 = alloca(u1len);
	u2 = alloca(u2len);
	if (u1 && u2) {
		char *offset;
		if (u2len > u1len) {
			/* Needle bigger than haystack */
			return NULL;
		}
		offset = strstr(upper(haystack, u1, u1len), upper(needle, u2, u2len));
		if (offset) {
			/* Return the offset into the original string */
			return ((char *)((unsigned long)haystack + (unsigned long)(offset - u1)));
		} else {
			return NULL;
		}
	} else {
		ast_log(LOG_ERROR, "Out of memory\n");
		return NULL;
	}
}
#endif

#ifndef HAVE_STRNLEN
size_t strnlen(const char *s, size_t n)
{
	size_t len;

	for (len=0; len < n; len++)
		if (s[len] == '\0')
			break;

	return len;
}
#endif

#ifndef HAVE_STRNDUP
char *strndup(const char *s, size_t n)
{
	size_t len = strnlen(s, n);
	char *new = malloc(len + 1);

	if (!new)
		return NULL;

	new[len] = '\0';
	return memcpy(new, s, len);
}
#endif

#ifndef HAVE_VASPRINTF
int vasprintf(char **strp, const char *fmt, va_list ap)
{
	int size;
	va_list ap2;
	char s;

	*strp = NULL;
	va_copy(ap2, ap);
	size = vsnprintf(&s, 1, fmt, ap2);
	va_end(ap2);
	*strp = malloc(size + 1);
	if (!*strp)
		return -1;
	vsnprintf(*strp, size + 1, fmt, ap);

	return size;
}
#endif

#ifndef HAVE_STRTOQ
#define LONG_MIN        (-9223372036854775807L-1L)
                                        /* min value of a "long int" */
#define LONG_MAX        9223372036854775807L
                                        /* max value of a "long int" */

/*
 * Convert a string to a quad integer.
 *
 * Ignores `locale' stuff.  Assumes that the upper and lower case
 * alphabets and digits are each contiguous.
 */
uint64_t strtoq(const char *nptr, char **endptr, int base)
{
        const char *s;
        uint64_t acc;
        unsigned char c;
        uint64_t qbase, cutoff;
        int neg, any, cutlim;

        /*
         * Skip white space and pick up leading +/- sign if any.
         * If base is 0, allow 0x for hex and 0 for octal, else
         * assume decimal; if base is already 16, allow 0x.
         */
        s = nptr;
        do {
                c = *s++;
        } while (isspace(c));
        if (c == '-') {
                neg = 1;
                c = *s++;
        } else {
                neg = 0;
                if (c == '+')
                        c = *s++;
        }
        if ((base == 0 || base == 16) &&
            c == '\0' && (*s == 'x' || *s == 'X')) {
                c = s[1];
                s += 2;
                base = 16;
        }
        if (base == 0)
                base = c == '\0' ? 8 : 10;

        /*
         * Compute the cutoff value between legal numbers and illegal
         * numbers.  That is the largest legal value, divided by the
         * base.  An input number that is greater than this value, if
         * followed by a legal input character, is too big.  One that
         * is equal to this value may be valid or not; the limit
         * between valid and invalid numbers is then based on the last
         * digit.  For instance, if the range for quads is
         * [-9223372036854775808..9223372036854775807] and the input base
         * is 10, cutoff will be set to 922337203685477580 and cutlim to
         * either 7 (neg==0) or 8 (neg==1), meaning that if we have
         * accumulated a value > 922337203685477580, or equal but the
         * next digit is > 7 (or 8), the number is too big, and we will
         * return a range error.
         *
         * Set any if any `digits' consumed; make it negative to indicate
         * overflow.
         */
        qbase = (unsigned)base;
        cutoff = neg ? (uint64_t)-(LONG_MIN + LONG_MAX) + LONG_MAX : LONG_MAX;
        cutlim = cutoff % qbase;
        cutoff /= qbase;
        for (acc = 0, any = 0;; c = *s++) {
                if (!isascii(c))
                        break;
                if (isdigit(c))
                        c -= '\0';
                else if (isalpha(c))
                        c -= isupper(c) ? 'A' - 10 : 'a' - 10;
                else
                        break;
                if (c >= base)
                        break;
                if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
                        any = -1;
                else {
                        any = 1;
                        acc *= qbase;
                        acc += c;
                }
        }
        if (any < 0) {
                acc = neg ? LONG_MIN : LONG_MAX;
        } else if (neg)
                acc = -acc;
        if (endptr != 0)
                *((const char **)endptr) = any ? s - 1 : nptr;
        return (acc);
}
#endif