src/lib/strfuncs.c

/* Copyright (c) 2002-2018 Dovecot authors, see the included COPYING file */

/* @UNSAFE: whole file */

#include "lib.h"
#include "printf-format-fix.h"
#include "strfuncs.h"
#include "array.h"

#include <stdio.h>
#include <limits.h>
#include <ctype.h>

#define STRCONCAT_BUFSIZE 512

enum _str_trim_sides {
    STR_TRIM_LEFT = BIT(0),
    STR_TRIM_RIGHT = BIT(1),
};

const unsigned char uchar_nul = '\0';
const unsigned char *uchar_empty_ptr = &uchar_nul;

volatile int timing_safety_unoptimization;

int i_snprintf(char *dest, size_t max_chars, const char *format, ...)
{
    va_list args;
    int ret;

    i_assert(max_chars < INT_MAX);

    va_start(args, format);
    ret = vsnprintf(dest, max_chars, printf_format_fix_unsafe(format),
            args);
    va_end(args);

    i_assert(ret >= 0);
    return (unsigned int)ret < max_chars ? 0 : -1;
}

char *p_strdup(pool_t pool, const char *str)
{
    void *mem;
    size_t len;

    if (str == NULL)
                return NULL;

    len = strlen(str) + 1;
    mem = p_malloc(pool, len);
    memcpy(mem, str, len);
    return mem;
}

void *p_memdup(pool_t pool, const void *data, size_t size)
{
    void *mem;

    mem = p_malloc(pool, size);
    memcpy(mem, data, size);
    return mem;
}

char *p_strdup_empty(pool_t pool, const char *str)
{
    if (str == NULL || *str == '\0')
                return NULL;

    return p_strdup(pool, str);
}

char *p_strdup_until(pool_t pool, const void *start, const void *end)
{
    size_t size;
    char *mem;

    i_assert((const char *) start <= (const char *) end);

    size = (size_t) ((const char *) end - (const char *) start);

    mem = p_malloc(pool, size + 1);
    memcpy(mem, start, size);
    return mem;
}

char *p_strndup(pool_t pool, const void *str, size_t max_chars)
{
    char *mem;
    size_t len;

    i_assert(str != NULL);
    i_assert(max_chars != (size_t)-1);

    len = 0;
    while (len < max_chars && ((const char *) str)[len] != '\0')
        len++;

    mem = p_malloc(pool, len+1);
    memcpy(mem, str, len);
    mem[len] = '\0';
    return mem;
}

char *p_strdup_printf(pool_t pool, const char *format, ...)
{
    va_list args;
        char *ret;

    va_start(args, format);
        ret = p_strdup_vprintf(pool, format, args);
    va_end(args);

    return ret;
}

char *t_noalloc_strdup_vprintf(const char *format, va_list args,
                   unsigned int *size_r)
{
#define SNPRINTF_INITIAL_EXTRA_SIZE 256
    va_list args2;
    char *tmp;
    size_t init_size;
    int ret;
#ifdef DEBUG
    int old_errno = errno;
#endif

    VA_COPY(args2, args);

    /* the format string is modified only if %m exists in it. it happens
       only in error conditions, so don't try to t_push() here since it'll
       just slow down the normal code path. */
    format = printf_format_fix_get_len(format, &init_size);
    init_size += SNPRINTF_INITIAL_EXTRA_SIZE;

    tmp = t_buffer_get(init_size);
    ret = vsnprintf(tmp, init_size, format, args);
    i_assert(ret >= 0);

    *size_r = ret + 1;
    if ((unsigned int)ret >= init_size) {
        /* didn't fit with the first guess. now we know the size,
           so try again. */
        tmp = t_buffer_get(*size_r);
        ret = vsnprintf(tmp, *size_r, format, args2);
        i_assert((unsigned int)ret == *size_r-1);
    }
#ifdef DEBUG
    /* we rely on errno not changing. it shouldn't. */
    i_assert(errno == old_errno);
#endif
    va_end(args2);
    return tmp;
}

char *p_strdup_vprintf(pool_t pool, const char *format, va_list args)
{
    char *tmp, *buf;
    unsigned int size;

    tmp = t_noalloc_strdup_vprintf(format, args, &size);
    if (pool->datastack_pool) {
        t_buffer_alloc(size);
        return tmp;
    } else {
        buf = p_malloc(pool, size);
        memcpy(buf, tmp, size - 1);
        return buf;
    }
}

char *vstrconcat(const char *str1, va_list args, size_t *ret_len)
{
    const char *str;
        char *temp;
    size_t bufsize, i, len;

    i_assert(str1 != NULL);

    str = str1;
    bufsize = STRCONCAT_BUFSIZE;
    temp = t_buffer_get(bufsize);

    i = 0;
    do {
        len = strlen(str);

        if (i + len >= bufsize) {
            /* need more memory */
            bufsize = nearest_power(i + len + 1);
            temp = t_buffer_reget(temp, bufsize);
        }

        memcpy(temp + i, str, len); i += len;

        /* next string */
        str = va_arg(args, const char *);
    } while (str != NULL);

    i_assert(i < bufsize);

    temp[i++] = '\0';
        *ret_len = i;
        return temp;
}

char *p_strconcat(pool_t pool, const char *str1, ...)
{
    va_list args;
    char *temp, *ret;
        size_t len;

    i_assert(str1 != NULL);

    va_start(args, str1);

    if (pool->datastack_pool) {
        ret = vstrconcat(str1, args, &len);
        t_buffer_alloc(len);
    } else {
        temp = vstrconcat(str1, args, &len);
        ret = p_malloc(pool, len);
        memcpy(ret, temp, len);
    }

    va_end(args);
        return ret;
}

const char *t_strdup(const char *str)
{
    return p_strdup(unsafe_data_stack_pool, str);
}

char *t_strdup_noconst(const char *str)
{
    return p_strdup(unsafe_data_stack_pool, str);
}

const char *t_strdup_empty(const char *str)
{
    return p_strdup_empty(unsafe_data_stack_pool, str);
}

const char *t_strdup_until(const void *start, const void *end)
{
    return p_strdup_until(unsafe_data_stack_pool, start, end);
}

const char *t_strndup(const void *str, size_t max_chars)
{
    i_assert(str != NULL);
    return p_strndup(unsafe_data_stack_pool, str, max_chars);
}

const char *t_strdup_printf(const char *format, ...)
{
    va_list args;
    const char *ret;

    va_start(args, format);
    ret = p_strdup_vprintf(unsafe_data_stack_pool, format, args);
    va_end(args);

    return ret;
}

const char *t_strdup_vprintf(const char *format, va_list args)
{
    return p_strdup_vprintf(unsafe_data_stack_pool, format, args);
}

const char *t_strconcat(const char *str1, ...)
{
    va_list args;
    const char *ret;
        size_t len;

    i_assert(str1 != NULL);

    va_start(args, str1);

    ret = vstrconcat(str1, args, &len);
    t_buffer_alloc(len);

    va_end(args);
        return ret;
}

const char *t_strcut(const char *str, char cutchar)
{
    const char *p;

    for (p = str; *p != '\0'; p++) {
        if (*p == cutchar)
                        return t_strdup_until(str, p);
    }

        return str;
}

const char *t_str_replace(const char *str, char from, char to)
{
    char *out;
    size_t i, len;

    if (strchr(str, from) == NULL)
        return str;

    len = strlen(str);
    out = t_malloc_no0(len + 1);
    for (i = 0; i < len; i++) {
        if (str[i] == from)
            out[i] = to;
        else
            out[i] = str[i];
    }
    out[i] = '\0';
    return out;
}

int i_strocpy(char *dest, const char *src, size_t dstsize)
{
    if (dstsize == 0)
        return -1;

    while (*src != '\0' && dstsize > 1) {
        *dest++ = *src++;
        dstsize--;
    }

    *dest = '\0';
    return *src == '\0' ? 0 : -1;
}

char *str_ucase(char *str)
{
    char *p;

    for (p = str; *p != '\0'; p++)
        *p = i_toupper(*p);
        return str;
}

char *str_lcase(char *str)
{
    char *p;

    for (p = str; *p != '\0'; p++)
        *p = i_tolower(*p);
        return str;
}

const char *t_str_lcase(const char *str)
{
    i_assert(str != NULL);

    return str_lcase(t_strdup_noconst(str));
}

const char *t_str_ucase(const char *str)
{
    i_assert(str != NULL);

    return str_ucase(t_strdup_noconst(str));
}

static void str_trim_parse(const char *str,
    const char *chars, enum _str_trim_sides sides,
    const char **begin_r, const char **end_r)
{
    const char *p, *pend, *begin, *end;

    *begin_r = *end_r = NULL;

    pend = str + strlen(str);
    if (pend == str)
        return;

    p = str;
    if ((sides & STR_TRIM_LEFT) != 0) {
        while (p < pend && strchr(chars, *p) != NULL)
            p++;
        if (p == pend)
            return;
    }
    begin = p;

    p = pend;
    if ((sides & STR_TRIM_RIGHT) != 0) {
        while (p > begin && strchr(chars, *(p-1)) != NULL)
            p--;
        if (p == begin)
            return;
    }
    end = p;

    *begin_r = begin;
    *end_r = end;
}

const char *t_str_trim(const char *str, const char *chars)
{
    const char *begin, *end;

    str_trim_parse(str, chars,
        STR_TRIM_LEFT | STR_TRIM_RIGHT, &begin, &end);
    if (begin == NULL)
        return "";
    return t_strdup_until(begin, end);
}

const char *p_str_trim(pool_t pool, const char *str, const char *chars)
{
    const char *begin, *end;

    str_trim_parse(str, chars,
        STR_TRIM_LEFT | STR_TRIM_RIGHT, &begin, &end);
    if (begin == NULL)
        return "";
    return p_strdup_until(pool, begin, end);
}

const char *str_ltrim(const char *str, const char *chars)
{
    const char *begin, *end;

    str_trim_parse(str, chars, STR_TRIM_LEFT, &begin, &end);
    if (begin == NULL)
        return "";
    return begin;
}

const char *t_str_ltrim(const char *str, const char *chars)
{
    return t_strdup(str_ltrim(str, chars));
}

const char *p_str_ltrim(pool_t pool, const char *str, const char *chars)
{
    return p_strdup(pool, str_ltrim(str, chars));
}

const char *t_str_rtrim(const char *str, const char *chars)
{
    const char *begin, *end;

    str_trim_parse(str, chars, STR_TRIM_RIGHT, &begin, &end);
    if (begin == NULL)
        return "";
    return t_strdup_until(begin, end);
}

const char *p_str_rtrim(pool_t pool, const char *str, const char *chars)
{
    const char *begin, *end;

    str_trim_parse(str, chars, STR_TRIM_RIGHT, &begin, &end);
    if (begin == NULL)
        return "";
    return p_strdup_until(pool, begin, end);
}

int null_strcmp(const char *s1, const char *s2)
{
    if (s1 == NULL)
        return s2 == NULL ? 0 : -1;
    if (s2 == NULL)
        return 1;

    return strcmp(s1, s2);
}

int null_strcasecmp(const char *s1, const char *s2)
{
        if (s1 == NULL)
                return s2 == NULL ? 0 : -1;
        if (s2 == NULL)
                return 1;

        return strcasecmp(s1, s2);
}

int i_memcasecmp(const void *p1, const void *p2, size_t size)
{
    const unsigned char *s1 = p1;
    const unsigned char *s2 = p2;
    int ret;

    while (size > 0) {
        ret = i_toupper(*s1) - i_toupper(*s2);
        if (ret != 0)
            return ret;

        s1++; s2++; size--;
    }

        return 0;
}

int i_strcmp_p(const char *const *p1, const char *const *p2)
{
    return strcmp(*p1, *p2);
}

int i_strcasecmp_p(const char *const *p1, const char *const *p2)
{
    return strcasecmp(*p1, *p2);
}

bool mem_equals_timing_safe(const void *p1, const void *p2, size_t size)
{
    const unsigned char *s1 = p1, *s2 = p2;
    size_t i;
    int ret = 0;

    for (i = 0; i < size; i++)
        ret |= s1[i] ^ s2[i];

    /* make sure the compiler optimizer doesn't try to break out of the
       above loop early. */
    timing_safety_unoptimization = ret;
    return ret == 0;
}

static char **
split_str_slow(pool_t pool, const char *data, const char *separators, bool spaces)
{
        char **array;
    char *str;
        unsigned int count, alloc_count, new_alloc_count;

    if (spaces) {
        /* skip leading separators */
        while (*data != '\0' && strchr(separators, *data) != NULL)
            data++;
    }
    if (*data == '\0')
        return p_new(pool, char *, 1);

    str = p_strdup(pool, data);

    alloc_count = 32;
    array = p_new(pool, char *, alloc_count);

    array[0] = str; count = 1;
    while (*str != '\0') {
        if (strchr(separators, *str) != NULL) {
            /* separator found */
            if (count+1 >= alloc_count) {
                                new_alloc_count = nearest_power(alloc_count+1);
                array = p_realloc(pool, array,
                          sizeof(char *) * alloc_count,
                          sizeof(char *) *
                          new_alloc_count);
                alloc_count = new_alloc_count;
            }

            *str = '\0';
            if (spaces) {
                while (str[1] != '\0' &&
                       strchr(separators, str[1]) != NULL)
                    str++;

                /* ignore trailing separators */
                if (str[1] == '\0')
                    break;
            }

            array[count++] = str+1;
        }

                str++;
    }

    i_assert(count < alloc_count);
        array[count] = NULL;

        return array;
}

static char **
split_str_fast(pool_t pool, const char *data, char sep)
{
    char **array, *str;
    unsigned int count, alloc_count, new_alloc_count;

    if (*data == '\0')
        return p_new(pool, char *, 1);

    str = p_strdup(pool, data);

    alloc_count = 32;
    array = p_new(pool, char *, alloc_count);

    array[0] = str; count = 1;
    while ((str = strchr(str, sep)) != NULL) {
        /* separator found */
        if (count+1 >= alloc_count) {
            new_alloc_count = nearest_power(alloc_count+1);
            array = p_realloc(pool, array,
                      sizeof(char *) * alloc_count,
                      sizeof(char *) *
                      new_alloc_count);
            alloc_count = new_alloc_count;
        }
        *str++ = '\0';
        array[count++] = str;
    }
    i_assert(count < alloc_count);
    i_assert(array[count] == NULL);

    return array;
}

static char **
split_str(pool_t pool, const char *data, const char *separators, bool spaces)
{
    i_assert(*separators != '\0');

    if (separators[1] == '\0' && !spaces)
        return split_str_fast(pool, data, separators[0]);
    else
        return split_str_slow(pool, data, separators, spaces);
}

const char **t_strsplit(const char *data, const char *separators)
{
    return (const char **)split_str(unsafe_data_stack_pool, data,
                    separators, FALSE);
}

const char **t_strsplit_spaces(const char *data, const char *separators)
{
    return (const char **)split_str(unsafe_data_stack_pool, data,
                    separators, TRUE);
}

char **p_strsplit(pool_t pool, const char *data, const char *separators)
{
    return split_str(pool, data, separators, FALSE);
}

char **p_strsplit_spaces(pool_t pool, const char *data,
             const char *separators)
{
    return split_str(pool, data, separators, TRUE);
}

void p_strsplit_free(pool_t pool, char **arr)
{
    p_free(pool, arr[0]);
    p_free(pool, arr);
}

unsigned int str_array_length(const char *const *arr)
{
    unsigned int count;

    if (arr == NULL)
        return 0;

    for (count = 0; *arr != NULL; arr++)
        count++;

    return count;
}

static char *
p_strarray_join_n(pool_t pool, const char *const *arr, unsigned int arr_len,
          const char *separator)
{
    size_t alloc_len, sep_len, len, pos, needed_space;
    unsigned int i;
    char *str;

    sep_len = strlen(separator);
        alloc_len = 64;
    str = t_buffer_get(alloc_len);
    pos = 0;

    for (i = 0; i < arr_len; i++) {
        len = strlen(arr[i]);
        needed_space = pos + len + sep_len + 1;
        if (needed_space > alloc_len) {
            alloc_len = nearest_power(needed_space);
            str = t_buffer_reget(str, alloc_len);
        }

        if (i != 0) {
            memcpy(str + pos, separator, sep_len);
            pos += sep_len;
        }

        memcpy(str + pos, arr[i], len);
        pos += len;
    }
    str[pos] = '\0';
    if (!pool->datastack_pool)
        return p_memdup(pool, str, pos + 1);
    t_buffer_alloc(pos + 1);
    return str;
}

const char *t_strarray_join(const char *const *arr, const char *separator)
{
    return p_strarray_join_n(unsafe_data_stack_pool, arr,
                 str_array_length(arr), separator);
}

bool str_array_remove(const char **arr, const char *value)
{
    const char **dest;

    for (; *arr != NULL; arr++) {
        if (strcmp(*arr, value) == 0) {
            /* found it. now move the rest. */
            for (dest = arr, arr++; *arr != NULL; arr++, dest++)
                *dest = *arr;
            *dest = NULL;
            return TRUE;
        }
    }
    return FALSE;
}

bool str_array_find(const char *const *arr, const char *value)
{
    for (; *arr != NULL; arr++) {
        if (strcmp(*arr, value) == 0)
            return TRUE;
    }
    return FALSE;
}

bool str_array_icase_find(const char *const *arr, const char *value)
{
    for (; *arr != NULL; arr++) {
        if (strcasecmp(*arr, value) == 0)
            return TRUE;
    }
    return FALSE;
}

const char **p_strarray_dup(pool_t pool, const char *const *arr)
{
    unsigned int i;
    const char **ret;
    char *p;
    size_t len, size = sizeof(const char *);

    /* @UNSAFE: integer overflow checks are missing */
    for (i = 0; arr[i] != NULL; i++)
        size += sizeof(const char *) + strlen(arr[i]) + 1;

    ret = p_malloc(pool, size);
    p = PTR_OFFSET(ret, sizeof(const char *) * (i + 1));
    for (i = 0; arr[i] != NULL; i++) {
        len = strlen(arr[i]) + 1;
        memcpy(p, arr[i], len);
        ret[i] = p;
        p += len;
    }
    i_assert(PTR_OFFSET(ret, size) == (void *)p);
    return ret;
}

const char *dec2str(uintmax_t number)
{
    return dec2str_buf(t_malloc_no0(MAX_INT_STRLEN), number);
}

char *dec2str_buf(char buffer[STATIC_ARRAY MAX_INT_STRLEN], uintmax_t number)
{
    int pos;

    pos = MAX_INT_STRLEN;
    buffer[--pos] = '\0';
    do {
        buffer[--pos] = (number % 10) + '0';
        number /= 10;
    } while (number != 0 && pos >= 0);

    i_assert(pos >= 0);
    return buffer + pos;
}

char *p_array_const_string_join(pool_t pool, const ARRAY_TYPE(const_string) *arr,
                const char *separator)
{
    if (array_count(arr) == 0)
        return "";
    return p_strarray_join_n(pool, array_idx(arr, 0), array_count(arr), separator);
}