[asterisk-commits] rmudgett: branch 1.8 r347811 - /branches/1.8/main/pbx.c
SVN commits to the Asterisk project
asterisk-commits at lists.digium.com
Thu Dec 8 19:19:26 CST 2011
Author: rmudgett
Date: Thu Dec 8 19:19:23 2011
New Revision: 347811
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=347811
Log:
Fix some parsing issues in add_exten_to_pattern_tree().
* Simplify compare_char() and avoid potential sign extension issue.
* Fix infinite loop in add_exten_to_pattern_tree() handling of character
set escape handling.
* Added buffer overflow checks in add_exten_to_pattern_tree() character
set collection.
* Made ignore empty character sets.
* Added escape character handling to end-of-range character in character
sets. This has a slight change in behavior if the end-of-range character
is an escape character. You must now escape it.
* Fix potential sign extension issue when expanding character set ranges.
* Made remove duplicated characters from character sets. The duplicate
characters lower extension matching priority and prevent duplicate
extension detection.
* Fix escape character handling when the escape character is trying to
escape the end-of-string. We could have continued processing characters
after the end of the exten string. We could have added the previous
character to the pattern matching tree incorrectly.
(closes issue ASTERISK-18909)
Reported by: Luke-Jr
Modified:
branches/1.8/main/pbx.c
Modified: branches/1.8/main/pbx.c
URL: http://svnview.digium.com/svn/asterisk/branches/1.8/main/pbx.c?view=diff&rev=347811&r1=347810&r2=347811
==============================================================================
--- branches/1.8/main/pbx.c (original)
+++ branches/1.8/main/pbx.c Thu Dec 8 19:19:23 2011
@@ -1017,9 +1017,6 @@
static struct match_char *already_in_tree(struct match_char *current, char *pat, int is_pattern);
static struct match_char *add_exten_to_pattern_tree(struct ast_context *con,
struct ast_exten *e1, int findonly);
-static struct match_char *add_pattern_node(struct ast_context *con,
- struct match_char *current, char *pattern, int is_pattern,
- int already, int specificity, struct match_char **parent);
static void create_match_char_tree(struct ast_context *con);
static struct ast_exten *get_canmatch_exten(struct match_char *node);
static void destroy_pattern_tree(struct match_char *pattern_tree);
@@ -1040,17 +1037,23 @@
static struct ast_context *find_context_locked(const char *context);
static struct ast_context *find_context(const char *context);
-/* a func for qsort to use to sort a char array */
+/*!
+ * \internal
+ * \brief Character array comparison function for qsort.
+ *
+ * \param a Left side object.
+ * \param b Right side object.
+ *
+ * \retval <0 if a < b
+ * \retval =0 if a = b
+ * \retval >0 if a > b
+ */
static int compare_char(const void *a, const void *b)
{
- const char *ac = a;
- const char *bc = b;
- if ((*ac) < (*bc))
- return -1;
- else if ((*ac) == (*bc))
- return 0;
- else
- return 1;
+ const unsigned char *ac = a;
+ const unsigned char *bc = b;
+
+ return *ac - *bc;
}
/* labels, contexts are case sensitive priority numbers are ints */
@@ -1914,34 +1917,42 @@
}
-static struct match_char *add_pattern_node(struct ast_context *con, struct match_char *current, char *pattern, int is_pattern, int already, int specificity, struct match_char **nextcharptr)
+struct pattern_node {
+ /*! Pattern node specificity */
+ int specif;
+ /*! Pattern node match characters. */
+ char buf[256];
+};
+
+static struct match_char *add_pattern_node(struct ast_context *con, struct match_char *current, const struct pattern_node *pattern, int is_pattern, int already, struct match_char **nextcharptr)
{
struct match_char *m;
-
- if (!(m = ast_calloc(1, sizeof(*m) + strlen(pattern)))) {
+
+ if (!(m = ast_calloc(1, sizeof(*m) + strlen(pattern->buf)))) {
return NULL;
}
/* strcpy is safe here since we know its size and have allocated
* just enough space for when we allocated m
*/
- strcpy(m->x, pattern);
+ strcpy(m->x, pattern->buf);
/* the specificity scores are the same as used in the old
pattern matcher. */
m->is_pattern = is_pattern;
- if (specificity == 1 && is_pattern && pattern[0] == 'N')
+ if (pattern->specif == 1 && is_pattern && pattern->buf[0] == 'N') {
m->specificity = 0x0832;
- else if (specificity == 1 && is_pattern && pattern[0] == 'Z')
+ } else if (pattern->specif == 1 && is_pattern && pattern->buf[0] == 'Z') {
m->specificity = 0x0931;
- else if (specificity == 1 && is_pattern && pattern[0] == 'X')
+ } else if (pattern->specif == 1 && is_pattern && pattern->buf[0] == 'X') {
m->specificity = 0x0a30;
- else if (specificity == 1 && is_pattern && pattern[0] == '.')
+ } else if (pattern->specif == 1 && is_pattern && pattern->buf[0] == '.') {
m->specificity = 0x18000;
- else if (specificity == 1 && is_pattern && pattern[0] == '!')
+ } else if (pattern->specif == 1 && is_pattern && pattern->buf[0] == '!') {
m->specificity = 0x28000;
- else
- m->specificity = specificity;
+ } else {
+ m->specificity = pattern->specif;
+ }
if (!con->pattern_tree) {
insert_in_next_chars_alt_char_list(&con->pattern_tree, m);
@@ -1956,111 +1967,220 @@
return m;
}
+/*!
+ * \internal
+ * \brief Extract the next exten pattern node.
+ *
+ * \param node Pattern node to fill.
+ * \param src Next source character to read.
+ * \param pattern TRUE if the exten is a pattern.
+ * \param extenbuf Original exten buffer to use in diagnostic messages.
+ *
+ * \retval Ptr to next extenbuf pos to read.
+ */
+static const char *get_pattern_node(struct pattern_node *node, const char *src, int pattern, const char *extenbuf)
+{
+#define INC_DST_OVERFLOW_CHECK \
+ do { \
+ if (dst - node->buf < sizeof(node->buf) - 1) { \
+ ++dst; \
+ } else { \
+ overflow = 1; \
+ } \
+ } while (0)
+
+ node->specif = 0;
+ node->buf[0] = '\0';
+ while (*src) {
+ if (*src == '[' && pattern) {
+ char *dst = node->buf;
+ const char *src_next;
+ int length;
+ int overflow = 0;
+
+ /* get past the '[' */
+ ++src;
+ for (;;) {
+ if (*src == '\\') {
+ /* Escaped character. */
+ ++src;
+ if (*src == '[' || *src == '\\' || *src == '-' || *src == ']') {
+ *dst = *src++;
+ INC_DST_OVERFLOW_CHECK;
+ }
+ } else if (*src == '-') {
+ unsigned char first;
+ unsigned char last;
+
+ src_next = src;
+ first = *(src_next - 1);
+ last = *++src_next;
+
+ if (last == '\\') {
+ /* Escaped character. */
+ last = *++src_next;
+ }
+
+ /* Possible char range. */
+ if (node->buf[0] && last) {
+ /* Expand the char range. */
+ while (++first <= last) {
+ *dst = first;
+ INC_DST_OVERFLOW_CHECK;
+ }
+ src = src_next + 1;
+ } else {
+ /*
+ * There was no left or right char for the range.
+ * It is just a '-'.
+ */
+ *dst = *src++;
+ INC_DST_OVERFLOW_CHECK;
+ }
+ } else if (*src == '\0') {
+ ast_log(LOG_WARNING,
+ "A matching ']' was not found for '[' in exten pattern '%s'\n",
+ extenbuf);
+ break;
+ } else if (*src == ']') {
+ ++src;
+ break;
+ } else {
+ *dst = *src++;
+ INC_DST_OVERFLOW_CHECK;
+ }
+ }
+ /* null terminate the exploded range */
+ *dst = '\0';
+
+ if (overflow) {
+ ast_log(LOG_ERROR,
+ "Expanded character set too large to deal with in exten pattern '%s'. Ignoring character set.\n",
+ extenbuf);
+ node->buf[0] = '\0';
+ continue;
+ }
+
+ /* Sort the characters in character set. */
+ length = strlen(node->buf);
+ if (!length) {
+ ast_log(LOG_WARNING, "Empty character set in exten pattern '%s'. Ignoring.\n",
+ extenbuf);
+ node->buf[0] = '\0';
+ continue;
+ }
+ qsort(node->buf, length, 1, compare_char);
+
+ /* Remove duplicate characters from character set. */
+ dst = node->buf;
+ src_next = node->buf;
+ while (*src_next++) {
+ if (*dst != *src_next) {
+ *++dst = *src_next;
+ }
+ }
+
+ length = strlen(node->buf);
+ length <<= 8;
+ node->specif = length | (unsigned char) node->buf[0];
+ break;
+ } else if (*src == '-') {
+ /* Skip dashes in all extensions. */
+ ++src;
+ } else {
+ if (*src == '\\') {
+ /*
+ * XXX The escape character here does not remove any special
+ * meaning to characters except the '[', '\\', and '-'
+ * characters since they are special only in this function.
+ */
+ node->buf[0] = *++src;
+ if (!node->buf[0]) {
+ break;
+ }
+ } else {
+ node->buf[0] = *src;
+ if (pattern) {
+ /* make sure n,x,z patterns are canonicalized to N,X,Z */
+ if (node->buf[0] == 'n') {
+ node->buf[0] = 'N';
+ } else if (node->buf[0] == 'x') {
+ node->buf[0] = 'X';
+ } else if (node->buf[0] == 'z') {
+ node->buf[0] = 'Z';
+ }
+ }
+ }
+ node->buf[1] = '\0';
+ node->specif = 1;
+ ++src;
+ break;
+ }
+ }
+ return src;
+
+#undef INC_DST_OVERFLOW_CHECK
+}
+
static struct match_char *add_exten_to_pattern_tree(struct ast_context *con, struct ast_exten *e1, int findonly)
{
- struct match_char *m1 = NULL, *m2 = NULL, **m0;
- int specif;
+ struct match_char *m1 = NULL;
+ struct match_char *m2 = NULL;
+ struct match_char **m0;
+ const char *pos;
int already;
int pattern = 0;
- char buf[256];
+ int idx_cur;
+ int idx_next;
char extenbuf[512];
- char *s1 = extenbuf;
- int l1 = strlen(e1->exten) + strlen(e1->cidmatch) + 2;
-
-
- ast_copy_string(extenbuf, e1->exten, sizeof(extenbuf));
-
- if (e1->matchcid && l1 <= sizeof(extenbuf)) {
- strcat(extenbuf, "/");
- strcat(extenbuf, e1->cidmatch);
- } else if (l1 > sizeof(extenbuf)) {
- ast_log(LOG_ERROR, "The pattern %s/%s is too big to deal with: it will be ignored! Disaster!\n", e1->exten, e1->cidmatch);
- return 0;
- }
+ struct pattern_node pat_node[2];
+
+ if (e1->matchcid) {
+ if (sizeof(extenbuf) < strlen(e1->exten) + strlen(e1->cidmatch) + 2) {
+ ast_log(LOG_ERROR,
+ "The pattern %s/%s is too big to deal with: it will be ignored! Disaster!\n",
+ e1->exten, e1->cidmatch);
+ return NULL;
+ }
+ sprintf(extenbuf, "%s/%s", e1->exten, e1->cidmatch);/* Safe. We just checked. */
+ } else {
+ ast_copy_string(extenbuf, e1->exten, sizeof(extenbuf));
+ }
+
#ifdef NEED_DEBUG
- ast_log(LOG_DEBUG, "Adding exten %s%c%s to tree\n", s1, e1->matchcid ? '/' : ' ', e1->matchcid ? e1->cidmatch : "");
+ ast_log(LOG_DEBUG, "Adding exten %s to tree\n", extenbuf);
#endif
m1 = con->pattern_tree; /* each pattern starts over at the root of the pattern tree */
m0 = &con->pattern_tree;
already = 1;
- if ( *s1 == '_') {
+ pos = extenbuf;
+ if (*pos == '_') {
pattern = 1;
- s1++;
- }
- while (*s1) {
- if (pattern && *s1 == '[' && *(s1 - 1) != '\\') {
- char *s2 = buf;
- buf[0] = 0;
- s1++; /* get past the '[' */
- while (*s1 != ']' && *(s1 - 1) != '\\') {
- if (*s1 == '\\') {
- if (*(s1 + 1) == ']') {
- *s2++ = ']';
- s1 += 2;
- } else if (*(s1 + 1) == '\\') {
- *s2++ = '\\';
- s1 += 2;
- } else if (*(s1 + 1) == '-') {
- *s2++ = '-';
- s1 += 2;
- } else if (*(s1 + 1) == '[') {
- *s2++ = '[';
- s1 += 2;
- }
- } else if (*s1 == '-') { /* remember to add some error checking to all this! */
- char s3 = *(s1 - 1);
- char s4 = *(s1 + 1);
- for (s3++; s3 <= s4; s3++) {
- *s2++ = s3;
- }
- s1 += 2;
- } else if (*s1 == '\0') {
- ast_log(LOG_WARNING, "A matching ']' was not found for '[' in pattern string '%s'\n", extenbuf);
- break;
- } else {
- *s2++ = *s1++;
- }
- }
- *s2 = 0; /* null terminate the exploded range */
- /* sort the characters */
-
- specif = strlen(buf);
- qsort(buf, specif, 1, compare_char);
- specif <<= 8;
- specif += buf[0];
- } else if (*s1 == '-') {
- /* Skip dashes in patterns */
- s1++;
- continue;
- } else {
- if (*s1 == '\\') {
- s1++;
- buf[0] = *s1;
- } else {
- if (pattern) {
- if (*s1 == 'n') { /* make sure n,x,z patterns are canonicalized to N,X,Z */
- *s1 = 'N';
- } else if (*s1 == 'x') {
- *s1 = 'X';
- } else if (*s1 == 'z') {
- *s1 = 'Z';
- }
- }
- buf[0] = *s1;
- }
- buf[1] = 0;
- specif = 1;
- }
- m2 = 0;
- if (already && (m2 = already_in_tree(m1, buf, pattern)) && m2->next_char) {
- if (!(*(s1 + 1))) { /* if this is the end of the pattern, but not the end of the tree, then mark this node with the exten...
- a shorter pattern might win if the longer one doesn't match */
+ ++pos;
+ }
+ idx_cur = 0;
+ pos = get_pattern_node(&pat_node[idx_cur], pos, pattern, extenbuf);
+ for (; pat_node[idx_cur].buf[0]; idx_cur = idx_next) {
+ idx_next = (idx_cur + 1) % ARRAY_LEN(pat_node);
+ pos = get_pattern_node(&pat_node[idx_next], pos, pattern, extenbuf);
+
+ /* See about adding node to tree. */
+ m2 = NULL;
+ if (already && (m2 = already_in_tree(m1, pat_node[idx_cur].buf, pattern))
+ && m2->next_char) {
+ if (!pat_node[idx_next].buf[0]) {
+ /*
+ * This is the end of the pattern, but not the end of the tree.
+ * Mark this node with the exten... a shorter pattern might win
+ * if the longer one doesn't match.
+ */
if (findonly) {
return m2;
}
if (m2->exten) {
- ast_log(LOG_WARNING, "Found duplicate exten. Had %s found %s\n", m2->deleted ? "(deleted/invalid)" : m2->exten->exten, e1->exten);
+ ast_log(LOG_WARNING, "Found duplicate exten. Had %s found %s\n",
+ m2->deleted ? "(deleted/invalid)" : m2->exten->exten, e1->exten);
}
m2->exten = e1;
m2->deleted = 0;
@@ -2077,14 +2197,16 @@
if (findonly) {
return m1;
}
- if (!(m1 = add_pattern_node(con, m1, buf, pattern, already,specif, m0))) { /* m1 is the node just added */
+ m1 = add_pattern_node(con, m1, &pat_node[idx_cur], pattern, already, m0);
+ if (!m1) { /* m1 is the node just added */
return NULL;
}
m0 = &m1->next_char;
}
- if (!(*(s1 + 1))) {
+ if (!pat_node[idx_next].buf[0]) {
if (m2 && m2->exten) {
- ast_log(LOG_WARNING, "Found duplicate exten. Had %s found %s\n", m2->deleted ? "(deleted/invalid)" : m2->exten->exten, e1->exten);
+ ast_log(LOG_WARNING, "Found duplicate exten. Had %s found %s\n",
+ m2->deleted ? "(deleted/invalid)" : m2->exten->exten, e1->exten);
}
m1->deleted = 0;
m1->exten = e1;
@@ -2095,7 +2217,6 @@
*/
already = 0;
}
- s1++; /* advance to next char */
}
return m1;
}
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