--- /dev/null
+/*
+ * LuCI Template - Utility functions
+ *
+ * Copyright (C) 2010 Jo-Philipp Wich <xm@subsignal.org>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "template_utils.h"
+
+/* initialize a buffer object */
+static struct template_buffer * buf_init(void)
+{
+ struct template_buffer *buf;
+
+ buf = (struct template_buffer *)malloc(sizeof(struct template_buffer));
+
+ if (buf != NULL)
+ {
+ buf->fill = 0;
+ buf->size = 1024;
+ buf->data = (unsigned char *)malloc(buf->size);
+
+ if (buf->data != NULL)
+ {
+ buf->dptr = buf->data;
+ buf->data[0] = 0;
+
+ return buf;
+ }
+
+ free(buf);
+ }
+
+ return NULL;
+}
+
+/* grow buffer */
+static int buf_grow(struct template_buffer *buf)
+{
+ unsigned int off = (buf->dptr - buf->data);
+ unsigned char *data =
+ (unsigned char *)realloc(buf->data, buf->size + 1024);
+
+ if (data != NULL)
+ {
+ buf->data = data;
+ buf->dptr = data + off;
+ buf->size += 1024;
+
+ return buf->size;
+ }
+
+ return 0;
+}
+
+/* put one char into buffer object */
+static int buf_putchar(struct template_buffer *buf, unsigned char c)
+{
+ if( ((buf->fill + 1) >= buf->size) && !buf_grow(buf) )
+ return 0;
+
+ *(buf->dptr++) = c;
+ *(buf->dptr) = 0;
+
+ buf->fill++;
+ return 1;
+}
+
+/* append data to buffer */
+static int buf_append(struct template_buffer *buf, unsigned char *s, int len)
+{
+ while ((buf->fill + len + 1) >= buf->size)
+ {
+ if (!buf_grow(buf))
+ return 0;
+ }
+
+ memcpy(buf->dptr, s, len);
+ buf->fill += len;
+ buf->dptr += len;
+
+ *(buf->dptr) = 0;
+
+ return len;
+}
+
+/* destroy buffer object and return pointer to data */
+static char * buf_destroy(struct template_buffer *buf)
+{
+ unsigned char *data = buf->data;
+
+ free(buf);
+ return (char *)data;
+}
+
+
+/* calculate the number of expected continuation chars */
+static inline int mb_num_chars(unsigned char c)
+{
+ if ((c & 0xE0) == 0xC0)
+ return 2;
+ else if ((c & 0xF0) == 0xE0)
+ return 3;
+ else if ((c & 0xF8) == 0xF0)
+ return 4;
+ else if ((c & 0xFC) == 0xF8)
+ return 5;
+ else if ((c & 0xFE) == 0xFC)
+ return 6;
+
+ return 1;
+}
+
+/* test whether the given byte is a valid continuation char */
+static inline int mb_is_cont(unsigned char c)
+{
+ return ((c >= 0x80) && (c <= 0xBF));
+}
+
+/* test whether the byte sequence at the given pointer with the given
+ * length is the shortest possible representation of the code point */
+static inline int mb_is_shortest(unsigned char *s, int n)
+{
+ switch (n)
+ {
+ case 2:
+ /* 1100000x (10xxxxxx) */
+ return ((*s & 0x1E) > 0);
+
+ case 3:
+ /* 11100000 100xxxxx (10xxxxxx) */
+ return ((*s & 0x1F) > 0) && ((*(s+1) & 0x60) > 0);
+
+ case 4:
+ /* 11110000 1000xxxx (10xxxxxx 10xxxxxx) */
+ return ((*s & 0x0F) > 0) && ((*(s+1) & 0x70) > 0);
+
+ case 5:
+ /* 11111000 10000xxx (10xxxxxx 10xxxxxx 10xxxxxx) */
+ return ((*s & 0x07) > 0) && ((*(s+1) & 0x78) > 0);
+
+ case 6:
+ /* 11111100 100000xx (10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx) */
+ return ((*s & 0x03) > 0) && ((*(s+1) & 0x7C) > 0);
+ }
+
+ return 1;
+}
+
+/* test whether the byte sequence at the given pointer with the given
+ * length is an UTF-16 surrogate */
+static inline int mb_is_surrogate(unsigned char *s, int n)
+{
+ return ((n == 3) && (*s == 0xED) && (*(s+1) >= 0xA0) && (*(s+1) <= 0xBF));
+}
+
+/* test whether the byte sequence at the given pointer with the given
+ * length is an illegal UTF-8 code point */
+static inline int mb_is_illegal(unsigned char *s, int n)
+{
+ return ((n == 3) && (*s == 0xEF) && (*(s+1) == 0xBF) &&
+ (*(s+2) >= 0xBE) && (*(s+2) <= 0xBF));
+}
+
+
+/* scan given source string, validate UTF-8 sequence and store result
+ * in given buffer object */
+static int _validate_utf8(unsigned char **s, int l, struct template_buffer *buf)
+{
+ unsigned char *ptr = *s;
+ unsigned int o = 0, v, n;
+
+ //for (o = 0; o < l; o++)
+ {
+ /* ascii byte without null */
+ if ((*(ptr+0) >= 0x01) && (*(ptr+0) <= 0x7F))
+ {
+ if (!buf_putchar(buf, *ptr++))
+ return 0;
+
+ o = 1;
+ }
+
+ /* multi byte sequence */
+ else if ((n = mb_num_chars(*ptr)) > 1)
+ {
+ /* count valid chars */
+ for (v = 1; (v <= n) && ((o+v) < l) && mb_is_cont(*(ptr+v)); v++);
+
+ switch (n)
+ {
+ case 6:
+ case 5:
+ /* five and six byte sequences are always invalid */
+ if (!buf_putchar(buf, '?'))
+ return 0;
+
+ break;
+
+ default:
+ /* if the number of valid continuation bytes matches the
+ * expected number and if the sequence is legal, copy
+ * the bytes to the destination buffer */
+ if ((v == n) && mb_is_shortest(ptr, n) &&
+ !mb_is_surrogate(ptr, n) && !mb_is_illegal(ptr, n))
+ {
+ /* copy sequence */
+ if (!buf_append(buf, ptr, n))
+ return 0;
+ }
+
+ /* the found sequence is illegal, skip it */
+ else
+ {
+ /* invalid sequence */
+ if (!buf_putchar(buf, '?'))
+ return 0;
+ }
+
+ break;
+ }
+
+ /* advance beyound the last found valid continuation char */
+ o = v;
+ ptr += v;
+ }
+
+ /* invalid byte (0x00) */
+ else
+ {
+ if (!buf_putchar(buf, '?')) /* or 0xEF, 0xBF, 0xBD */
+ return 0;
+
+ o = 1;
+ ptr++;
+ }
+ }
+
+ *s = ptr;
+ return o;
+}
+
+/* sanitize given string and replace all invalid UTF-8 sequences with "?" */
+char * sanitize_utf8(const char *s, unsigned int l)
+{
+ struct template_buffer *buf = buf_init();
+ unsigned char *ptr = (unsigned char *)s;
+
+ if (!buf)
+ return NULL;
+
+ if (!_validate_utf8(&ptr, l, buf))
+ {
+ free(buf->data);
+ free(buf);
+ return NULL;
+ }
+
+ return buf_destroy(buf);
+}
+
+/* Sanitize given string and strip all invalid XML bytes
+ * Validate UTF-8 sequences
+ * Escape XML control chars */
+char * sanitize_pcdata(const char *s, unsigned int l)
+{
+ struct template_buffer *buf = buf_init();
+ unsigned char *ptr = (unsigned char *)s;
+ unsigned int o, v;
+ char esq[8];
+ int esl;
+
+ if (!buf)
+ return NULL;
+
+ for (o = 0; o < l; o++)
+ {
+ /* Invalid XML bytes */
+ if (((*ptr >= 0x00) && (*ptr <= 0x08)) ||
+ ((*ptr >= 0x0B) && (*ptr <= 0x0C)) ||
+ ((*ptr >= 0x0E) && (*ptr <= 0x1F)) ||
+ (*ptr == 0x7F))
+ {
+ ptr++;
+ }
+
+ /* Escapes */
+ else if ((*ptr == 0x26) ||
+ (*ptr == 0x27) ||
+ (*ptr == 0x22) ||
+ (*ptr == 0x3C) ||
+ (*ptr == 0x3E))
+ {
+ esl = snprintf(esq, sizeof(esq), "&#%i;", *ptr);
+
+ if (!buf_append(buf, (unsigned char *)esq, esl))
+ break;
+
+ ptr++;
+ }
+
+ /* ascii char */
+ else if (*ptr <= 0x7F)
+ {
+ buf_putchar(buf, *ptr++);
+ }
+
+ /* multi byte sequence */
+ else
+ {
+ if (!(v = _validate_utf8(&ptr, l - o, buf)))
+ break;
+
+ o += (v - 1);
+ }
+ }
+
+ return buf_destroy(buf);
+}
projects / oweals / luci.git / commitdiff