lighttpd1.4/src/buffer.c

#include "first.h"

#include "buffer.h"

#include <stdlib.h>
#include <string.h>
#include <time.h>       /* strftime() */

static const char hex_chars_lc[] = "0123456789abcdef";
static const char hex_chars_uc[] = "0123456789ABCDEF";

/**
 * init the buffer
 *
 */

buffer* buffer_init(void) {
	buffer *b;

	b = malloc(sizeof(*b));
	force_assert(b);

	b->ptr = NULL;
	b->size = 0;
	b->used = 0;

	return b;
}

buffer *buffer_init_buffer(const buffer *src) {
	buffer *b = buffer_init();
	buffer_copy_buffer(b, src);
	return b;
}

buffer *buffer_init_string(const char *str) {
	buffer *b = buffer_init();
	buffer_copy_string(b, str);
	return b;
}

void buffer_free(buffer *b) {
	if (NULL == b) return;

	free(b->ptr);
	free(b);
}

void buffer_free_ptr(buffer *b) {
	free(b->ptr);
	b->ptr = NULL;
	b->used = 0;
	b->size = 0;
}

void buffer_move(buffer * restrict b, buffer * restrict src) {
	buffer tmp;
	force_assert(NULL != b);
	force_assert(NULL != src);

	buffer_clear(b);
	tmp = *src; *src = *b; *b = tmp;
}

/* make sure buffer is at least "size" big + 1 for '\0'. keep old data */
__attribute_cold__
static void buffer_realloc(buffer * const b, const size_t len) {
    #define BUFFER_PIECE_SIZE 64uL  /*(must be power-of-2)*/
    const size_t sz = (len + 1 + BUFFER_PIECE_SIZE-1) & ~(BUFFER_PIECE_SIZE-1);
    force_assert(sz > len);

    b->size = sz;
    b->ptr = realloc(b->ptr, sz);

    force_assert(NULL != b->ptr);
}

__attribute_cold__
__attribute_noinline__
static void buffer_alloc_replace(buffer * const b, const size_t size) {
    force_assert(NULL != b);
    /*(discard old data so realloc() does not copy)*/
    if (NULL != b->ptr) {
        free(b->ptr);
        b->ptr = NULL;
    }
    buffer_realloc(b, size);
}

char* buffer_string_prepare_copy(buffer * const b, const size_t size) {
	if (NULL == b->ptr || size >= b->size) buffer_alloc_replace(b, size);

	b->used = 0;
	return b->ptr;
}

__attribute_cold__
__attribute_noinline__
__attribute_returns_nonnull__
static char* buffer_string_prepare_append_resize(buffer * const b, const size_t size) {
	force_assert(NULL !=  b);
	if (buffer_string_is_empty(b)) {
		return buffer_string_prepare_copy(b, size);
	} else {
		/* not empty, b->used already includes a terminating 0 */
		size_t req_size = b->used + size;

		/* check for overflow: unsigned overflow is defined to wrap around */
		force_assert(req_size >= b->used);

		buffer_realloc(b, req_size);

		return b->ptr + b->used - 1;
	}
}

char* buffer_string_prepare_append(buffer * const b, const size_t size) {
    return (NULL != b->ptr && size < b->size - b->used)
      ? b->ptr + b->used - (0 != b->used)
      : buffer_string_prepare_append_resize(b, size);
}

void buffer_string_set_length(buffer *b, uint32_t len) {
	force_assert(NULL != b);

	if (len >= b->size) buffer_realloc(b, len);

	b->used = len + 1;
	b->ptr[len] = '\0';
}

void buffer_commit(buffer *b, size_t size)
{
	force_assert(NULL != b);
	force_assert(b->size > 0);

	if (0 == b->used) b->used = 1;

	if (size > 0) {
		/* check for overflow: unsigned overflow is defined to wrap around */
		size_t sz = b->used + size;
		force_assert(sz > b->used);
		force_assert(sz <= b->size);
		b->used = sz;
	}

	b->ptr[b->used - 1] = '\0';
}

void buffer_copy_string(buffer * restrict b, const char * restrict s) {
	buffer_copy_string_len(b, s, NULL != s ? strlen(s) : 0);
}

void buffer_copy_string_len(buffer * const restrict b, const char * const restrict s, const size_t s_len) {
	if (NULL == b->ptr || s_len >= b->size) buffer_alloc_replace(b, s_len);

	b->used = s_len + 1;
	b->ptr[s_len] = '\0';
	if (0 != s_len) memcpy(b->ptr, s, s_len); /*(s might be NULL)*/
}

void buffer_append_string(buffer * restrict b, const char * restrict s) {
	buffer_append_string_len(b, s, NULL != s ? strlen(s) : 0);
}

/**
 * append a string to the end of the buffer
 *
 * the resulting buffer is terminated with a '\0'
 * s is treated as a un-terminated string (a \0 is handled a normal character)
 *
 * @param b a buffer
 * @param s the string
 * @param s_len size of the string (without the terminating \0)
 */

void buffer_append_string_len(buffer * const restrict b, const char * const restrict s, const size_t s_len) {
	char * const target_buf = buffer_string_prepare_append(b, s_len);
	b->used += s_len + (0 == b->used); /*(must include '\0' for append)*/
	target_buf[s_len] = '\0';

	/*(s might be NULL if 0 == s_len)*/
	if (s_len) memcpy(target_buf, s, s_len);
}

void buffer_append_path_len(buffer * restrict b, const char * restrict a, size_t alen) {
    size_t blen = buffer_string_length(b);
    int aslash = (alen && a[0] == '/');
    buffer_string_prepare_append(b, alen+2); /*(+ '/' and + '\0' if 0 == blen)*/
    if (blen && b->ptr[blen-1] == '/') {
        if (aslash) --b->used;
    }
    else {
        if (!b->used) ++b->used;
        if (!aslash) b->ptr[++b->used - 2] = '/';
    }
    memcpy(b->ptr+b->used-1, a, alen);
    b->ptr[(b->used += alen)-1] = '\0';
}

void buffer_append_uint_hex_lc(buffer *b, uintmax_t value) {
	char *buf;
	unsigned int shift = 0;

	{
		uintmax_t copy = value;
		do {
			copy >>= 8;
			shift += 8; /* counting bits */
		} while (0 != copy);
	}

	buf = buffer_string_prepare_append(b, shift >> 2); /*nibbles (4 bits)*/
	buffer_commit(b, shift >> 2); /* will fill below */

	while (shift > 0) {
		shift -= 4;
		*(buf++) = hex_chars_lc[(value >> shift) & 0x0F];
	}
}

__attribute_returns_nonnull__
static char* utostr(char * const buf_end, uintmax_t val) {
	char *cur = buf_end;
	do {
		int mod = val % 10;
		val /= 10;
		/* prepend digit mod */
		*(--cur) = (char) ('0' + mod);
	} while (0 != val);
	return cur;
}

__attribute_returns_nonnull__
static char* itostr(char * const buf_end, intmax_t val) {
	/* absolute value not defined for INTMAX_MIN, but can take absolute
	 * value of any negative number via twos complement cast to unsigned.
	 * negative sign is prepended after (now unsigned) value is converted
	 * to string */
	uintmax_t uval = val >= 0 ? (uintmax_t)val : ((uintmax_t)~val) + 1;
	char *cur = utostr(buf_end, uval);
	if (val < 0) *(--cur) = '-';

	return cur;
}

void buffer_append_int(buffer *b, intmax_t val) {
	char buf[LI_ITOSTRING_LENGTH];
	char* const buf_end = buf + sizeof(buf);
	char *str;

	force_assert(NULL != b);

	str = itostr(buf_end, val);
	force_assert(buf_end > str && str >= buf);

	buffer_append_string_len(b, str, buf_end - str);
}

void buffer_append_strftime(buffer * const restrict b, const char * const restrict format, const struct tm * const restrict tm) {
	size_t rv;
	char* buf;
	force_assert(NULL != format);
	force_assert(NULL != tm);

	buf = buffer_string_prepare_append(b, 255);
	rv = strftime(buf, buffer_string_space(b), format, tm);

	/* 0 (in some apis buffer_string_space(b)) signals the string may have
	 * been too small; but the format could also just have lead to an empty
	 * string
	 */
	if (0 == rv || rv >= buffer_string_space(b)) {
		/* give it a second try with a larger string */
		buf = buffer_string_prepare_append(b, 4095);
		rv = strftime(buf, buffer_string_space(b), format, tm);
	}

	if (rv >= buffer_string_space(b)) rv = 0;

	buffer_commit(b, rv);
}


size_t li_itostrn(char *buf, size_t buf_len, intmax_t val) {
	char p_buf[LI_ITOSTRING_LENGTH];
	char* const str = itostr(p_buf+sizeof(p_buf), val);
	size_t len = (size_t)(p_buf+sizeof(p_buf)-str);
	force_assert(len <= buf_len);
	memcpy(buf, str, len);
	return len;
}

size_t li_utostrn(char *buf, size_t buf_len, uintmax_t val) {
	char p_buf[LI_ITOSTRING_LENGTH];
	char* const str = utostr(p_buf+sizeof(p_buf), val);
	size_t len = (size_t)(p_buf+sizeof(p_buf)-str);
	force_assert(len <= buf_len);
	memcpy(buf, str, len);
	return len;
}

#define li_ntox_lc(n) ((n) <= 9 ? (n) + '0' : (n) + 'a' - 10)

char int2hex(char c) {
	/*return li_ntox_lc(c & 0xF);*/
	return hex_chars_lc[(c & 0x0F)];
}

/* c (char) and n (nibble) MUST be unsigned integer types */
#define li_cton(c,n) \
  (((n) = (c) - '0') <= 9 || (((n) = ((c)&0xdf) - 'A') <= 5 ? ((n) += 10) : 0))

/* converts hex char (0-9, A-Z, a-z) to decimal.
 * returns 0xFF on invalid input.
 */
char hex2int(unsigned char hex) {
	unsigned char n;
	return li_cton(hex,n) ? (char)n : 0xFF;
}


int buffer_eq_icase_ssn(const char * const a, const char * const b, const size_t len) {
    for (size_t i = 0; i < len; ++i) {
        unsigned int ca = ((unsigned char *)a)[i];
        unsigned int cb = ((unsigned char *)b)[i];
        if (ca != cb) {
            ca |= 0x20;
            cb |= 0x20;
            if (ca != cb) return 0;
            if (!light_islower(ca)) return 0;
            if (!light_islower(cb)) return 0;
        }
    }
    return 1;
}

int buffer_eq_icase_ss(const char * const a, const size_t alen, const char * const b, const size_t blen) {
    /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
    return (alen == blen && buffer_eq_icase_ssn(a, b, blen));
}

int buffer_eq_icase_slen(const buffer * const b, const char * const s, const size_t slen) {
    /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
    /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
    return (b->used == slen + 1 && buffer_eq_icase_ssn(b->ptr, s, slen));
}

int buffer_eq_slen(const buffer * const b, const char * const s, const size_t slen) {
    /* Note: b must be initialized, i.e. 0 != b->used; uninitialized is not eq*/
    /* 1 = equal; 0 = not equal */ /* short string sizes expected (< INT_MAX) */
    return (b->used == slen + 1 && 0 == memcmp(b->ptr, s, slen));
}


/**
 * check if two buffer contain the same data
 */

int buffer_is_equal(const buffer *a, const buffer *b) {
	force_assert(NULL != a && NULL != b);

	/* 1 = equal; 0 = not equal */
	return (a->used == b->used && 0 == memcmp(a->ptr, b->ptr, a->used));
}

int buffer_is_equal_string(const buffer *a, const char *s, size_t b_len) {
	force_assert(NULL != a && NULL != s);
	force_assert(b_len + 1 > b_len);

	/* 1 = equal; 0 = not equal */
	return (a->used == b_len + 1 && 0 == memcmp(a->ptr, s, b_len));
}

/* buffer_is_equal_caseless_string(b, CONST_STR_LEN("value")) */
int buffer_is_equal_caseless_string(const buffer *a, const char *s, size_t b_len) {
	force_assert(NULL != a && NULL != s);
	force_assert(b_len + 1 > b_len);
	/* 1 = equal; 0 = not equal */
	return buffer_eq_icase_slen(a, s, b_len);
}

int buffer_is_equal_right_len(const buffer *b1, const buffer *b2, size_t len) {
	/* no len -> equal */
	if (len == 0) return 1;

	/* len > 0, but empty buffers -> not equal */
	if (b1->used == 0 || b2->used == 0) return 0;

	/* buffers too small -> not equal */
	if (b1->used - 1 < len || b2->used - 1 < len) return 0;

	return 0 == memcmp(b1->ptr + b1->used - 1 - len, b2->ptr + b2->used - 1 - len, len);
}


void li_tohex_lc(char * const restrict buf, size_t buf_len, const char * const restrict s, size_t s_len) {
	force_assert(2 * s_len > s_len);
	force_assert(2 * s_len < buf_len);

	for (size_t i = 0; i < s_len; ++i) {
		buf[2*i]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
		buf[2*i+1] = hex_chars_lc[s[i] & 0x0F];
	}
	buf[2*s_len] = '\0';
}

void li_tohex_uc(char * const restrict buf, size_t buf_len, const char * const restrict s, size_t s_len) {
	force_assert(2 * s_len > s_len);
	force_assert(2 * s_len < buf_len);

	for (size_t i = 0; i < s_len; ++i) {
		buf[2*i]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
		buf[2*i+1] = hex_chars_uc[s[i] & 0x0F];
	}
	buf[2*s_len] = '\0';
}


void buffer_substr_replace (buffer * const restrict b, const size_t offset,
                            const size_t len, const buffer * const restrict replace)
{
    const size_t blen = buffer_string_length(b);
    const size_t rlen = buffer_string_length(replace);

    if (rlen > len) {
        buffer_string_set_length(b, blen-len+rlen);
        memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
    }

    memcpy(b->ptr+offset, replace->ptr, rlen);

    if (rlen < len) {
        memmove(b->ptr+offset+rlen, b->ptr+offset+len, blen-offset-len);
        buffer_string_set_length(b, blen-len+rlen);
    }
}


void buffer_append_string_encoded_hex_lc(buffer * const restrict b, const char * const restrict s, size_t len) {
    unsigned char * const p =
      (unsigned char*) buffer_string_prepare_append(b, len*2);
    buffer_commit(b, len*2); /* fill below */
    for (size_t i = 0; i < len; ++i) {
        p[(i<<1)]   = hex_chars_lc[(s[i] >> 4) & 0x0F];
        p[(i<<1)+1] = hex_chars_lc[(s[i])      & 0x0F];
    }
}

void buffer_append_string_encoded_hex_uc(buffer * const restrict b, const char * const restrict s, size_t len) {
    unsigned char * const p =
      (unsigned char*) buffer_string_prepare_append(b, len*2);
    buffer_commit(b, len*2); /* fill below */
    for (size_t i = 0; i < len; ++i) {
        p[(i<<1)]   = hex_chars_uc[(s[i] >> 4) & 0x0F];
        p[(i<<1)+1] = hex_chars_uc[(s[i])      & 0x0F];
    }
}


/* everything except: ! ( ) * - . 0-9 A-Z _ a-z */
static const char encoded_chars_rel_uri_part[] = {
	/*
	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
	*/
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 1,  /*  20 -  2F space " # $ % & ' + , / */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
};

/* everything except: ! ( ) * - . / 0-9 A-Z _ a-z */
static const char encoded_chars_rel_uri[] = {
	/*
	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
	*/
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
	1, 0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 0, 0, 0,  /*  20 -  2F space " # $ % & ' + , */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1,  /*  30 -  3F : ; < = > ? */
	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F @ */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 0,  /*  50 -  5F [ \ ] ^ */
	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 0, 1,  /*  70 -  7F { | } DEL */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
};

static const char encoded_chars_html[] = {
	/*
	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
	*/
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  80 -  8F */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  90 -  9F */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  A0 -  AF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  B0 -  BF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  C0 -  CF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  D0 -  DF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  E0 -  EF */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  F0 -  FF */
};

static const char encoded_chars_minimal_xml[] = {
	/*
	0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F
	*/
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  00 -  0F control chars */
	1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,  /*  10 -  1F */
	0, 0, 1, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0,  /*  20 -  2F " & ' */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0,  /*  30 -  3F < > */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  40 -  4F */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  50 -  5F */
	1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,  /*  60 -  6F ` */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1,  /*  70 -  7F DEL */
	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,