X-Git-Url: https://git.exim.org/exim.git/blobdiff_plain/4fab92fbc2b63bac2d89c1dae69fa1845cb640b7..25beaee4c28ed29a37078e6c68fa3d18ced6ec8c:/src/src/string.c

diff --git a/src/src/string.c b/src/src/string.c
index be1a1d7a4..3abe2a3bd 100644
--- a/src/src/string.c
+++ b/src/src/string.c
@@ -2,7 +2,7 @@
 *     Exim - an Internet mail transport agent    *
 *************************************************/
 
-/* Copyright (c) University of Cambridge 1995 - 2016 */
+/* Copyright (c) University of Cambridge 1995 - 2018 */
 /* See the file NOTICE for conditions of use and distribution. */
 
 /* Miscellaneous string-handling functions. Some are not required for
@@ -42,7 +42,7 @@ int yield = 4;
 /* If an optional mask is permitted, check for it. If found, pass back the
 offset. */
 
-if (maskptr != NULL)
+if (maskptr)
   {
   const uschar *ss = s + Ustrlen(s);
   *maskptr = 0;
@@ -79,7 +79,7 @@ if (Ustrchr(s, ':') != NULL)
     if we hit the / that introduces a mask or the % that introduces the
     interface specifier (scope id) of a link-local address. */
 
-    if (*s == 0 || *s == '%' || *s == '/') return had_double_colon? yield : 0;
+    if (*s == 0 || *s == '%' || *s == '/') return had_double_colon ? yield : 0;
 
     /* If a component starts with an additional colon, we have hit a double
     colon. This is permitted to appear once only, and counts as at least
@@ -135,13 +135,16 @@ if (Ustrchr(s, ':') != NULL)
 
 for (i = 0; i < 4; i++)
   {
+  long n;
+  uschar * end;
+
   if (i != 0 && *s++ != '.') return 0;
-  if (!isdigit(*s++)) return 0;
-  if (isdigit(*s) && isdigit(*(++s))) s++;
+  n = strtol(CCS s, CSS &end, 10);
+  if (n > 255 || n < 0 || end <= s || end > s+3) return 0;
+  s = end;
   }
 
-return (*s == 0 || (*s == '/' && maskptr != NULL && *maskptr != 0))?
-  yield : 0;
+return !*s || (*s == '/' && maskptr && *maskptr != 0) ? yield : 0;
 }
 #endif  /* COMPILE_UTILITY */
 
@@ -306,7 +309,7 @@ expanded string. */
 
 ss = store_get(length + nonprintcount * 3 + 1);
 
-/* Copy everying, escaping non printers. */
+/* Copy everything, escaping non printers. */
 
 t = s;
 tt = ss;
@@ -911,7 +914,7 @@ sep_is_special = iscntrl(sep);
 
 /* Handle the case when a buffer is provided. */
 
-if (buffer != NULL)
+if (buffer)
   {
   int p = 0;
   for (; *s != 0; s++)
@@ -927,9 +930,8 @@ if (buffer != NULL)
 
 else
   {
-  int size = 0;
-  int ptr = 0;
   const uschar *ss;
+  gstring * g = NULL;
 
   /* We know that *s != 0 at this point. However, it might be pointing to a
   separator, which could indicate an empty string, or (if an ispunct()
@@ -951,13 +953,14 @@ else
 
   for (;;)
     {
-    for (ss = s + 1; *ss != 0 && *ss != sep; ss++);
-    buffer = string_catn(buffer, &size, &ptr, s, ss-s);
+    for (ss = s + 1; *ss != 0 && *ss != sep; ss++) ;
+    g = string_catn(g, s, ss-s);
     s = ss;
     if (*s == 0 || *(++s) != sep || sep_is_special) break;
     }
-  while (ptr > 0 && isspace(buffer[ptr-1])) ptr--;
-  buffer[ptr] = 0;
+  while (g->ptr > 0 && isspace(g->s[g->ptr-1])) g->ptr--;
+  buffer = string_from_gstring(g);
+  gstring_reset_unused(g);
   }
 
 /* Update the current pointer and return the new string */
@@ -965,104 +968,176 @@ else
 *listptr = s;
 return buffer;
 }
-#endif  /* COMPILE_UTILITY */
 
 
-#ifndef COMPILE_UTILITY
+static const uschar *
+Ustrnchr(const uschar * s, int c, unsigned * len)
+{
+unsigned siz = *len;
+while (siz)
+  {
+  if (!*s) return NULL;
+  if (*s == c)
+    {
+    *len = siz;
+    return s;
+    }
+  s++;
+  siz--;
+  }
+return NULL;
+}
+
+
 /************************************************
 *	Add element to separated list           *
 ************************************************/
-/* This function is used to build a list, returning
-an allocated null-terminated growable string. The
-given element has any embedded seperator characters
+/* This function is used to build a list, returning an allocated null-terminated
+growable string. The given element has any embedded separator characters
 doubled.
 
+Despite having the same growable-string interface as string_cat() the list is
+always returned null-terminated.
+
 Arguments:
-  list	points to the start of the list that is being built, or NULL
+  list	expanding-string for the list that is being built, or NULL
 	if this is a new list that has no contents yet
-  sep	list seperator charactoer
-  ele	new lement to be appended to the list
+  sep	list separator character
+  ele	new element to be appended to the list
 
 Returns:  pointer to the start of the list, changed if copied for expansion.
 */
 
-uschar *
-string_append_listele(uschar * list, uschar sep, const uschar * ele)
+gstring *
+string_append_listele(gstring * list, uschar sep, const uschar * ele)
 {
-uschar * new = NULL;
-int sz = 0, off = 0;
 uschar * sp;
 
-if (list)
-  {
-  new = string_cat (new, &sz, &off, list);
-  new = string_catn(new, &sz, &off, &sep, 1);
-  }
+if (list && list->ptr)
+  list = string_catn(list, &sep, 1);
 
 while((sp = Ustrchr(ele, sep)))
   {
-  new = string_catn(new, &sz, &off, ele, sp-ele+1);
-  new = string_catn(new, &sz, &off, &sep, 1);
+  list = string_catn(list, ele, sp-ele+1);
+  list = string_catn(list, &sep, 1);
   ele = sp+1;
   }
-new = string_cat(new, &sz, &off, ele);
-new[off] = '\0';
-return new;
+list = string_cat(list, ele);
+(void) string_from_gstring(list);
+return list;
 }
 
 
-static const uschar *
-Ustrnchr(const uschar * s, int c, unsigned * len)
+gstring *
+string_append_listele_n(gstring * list, uschar sep, const uschar * ele,
+ unsigned len)
 {
-unsigned siz = *len;
-while (siz)
-  {
-  if (!*s) return NULL;
-  if (*s == c)
-    {
-    *len = siz;
-    return s;
-    }
-  s++;
-  siz--;
-  }
-return NULL;
-}
-
-uschar *
-string_append_listele_n(uschar * list, uschar sep, const uschar * ele,
-  unsigned len)
-{
-uschar * new = NULL;
-int sz = 0, off = 0;
 const uschar * sp;
 
-if (list)
-  {
-  new = string_cat (new, &sz, &off, list);
-  new = string_catn(new, &sz, &off, &sep, 1);
-  }
+if (list && list->ptr)
+  list = string_catn(list, &sep, 1);
 
 while((sp = Ustrnchr(ele, sep, &len)))
   {
-  new = string_catn(new, &sz, &off, ele, sp-ele+1);
-  new = string_catn(new, &sz, &off, &sep, 1);
+  list = string_catn(list, ele, sp-ele+1);
+  list = string_catn(list, &sep, 1);
   ele = sp+1;
   len--;
   }
-new = string_catn(new, &sz, &off, ele, len);
-new[off] = '\0';
-return new;
+list = string_catn(list, ele, len);
+(void) string_from_gstring(list);
+return list;
 }
-#endif  /* COMPILE_UTILITY */
 
 
 
-#ifndef COMPILE_UTILITY
+/* A slightly-bogus listmaker utility; the separator is a string so
+can be multiple chars - there is no checking for the element content
+containing any of the separator. */
+
+gstring *
+string_append2_listele_n(gstring * list, const uschar * sepstr,
+ const uschar * ele, unsigned len)
+{
+if (list && list->ptr)
+  list = string_cat(list, sepstr);
+
+list = string_catn(list, ele, len);
+(void) string_from_gstring(list);
+return list;
+}
+
+
+
+/************************************************/
+/* Create a growable-string with some preassigned space */
+
+gstring *
+string_get(unsigned size)
+{
+gstring * g = store_get(sizeof(gstring) + size);
+g->size = size;
+g->ptr = 0;
+g->s = US(g + 1);
+return g;
+}
+
+/* NUL-terminate the C string in the growable-string, and return it. */
+
+uschar *
+string_from_gstring(gstring * g)
+{
+if (!g) return NULL;
+g->s[g->ptr] = '\0';
+return g->s;
+}
+
+void
+gstring_reset_unused(gstring * g)
+{
+store_reset(g->s + (g->size = g->ptr + 1));
+}
+
 /*************************************************
 *             Add chars to string                *
 *************************************************/
 
+/* Arguments:
+  g		the grawable-string
+  p		current end of data
+  count		amount to grow by
+*/
+
+static void
+gstring_grow(gstring * g, int p, int count)
+{
+int oldsize = g->size;
+
+/* Mostly, string_cat() is used to build small strings of a few hundred
+characters at most. There are times, however, when the strings are very much
+longer (for example, a lookup that returns a vast number of alias addresses).
+To try to keep things reasonable, we use increments whose size depends on the
+existing length of the string. */
+
+unsigned inc = oldsize < 4096 ? 127 : 1023;
+g->size = ((p + count + inc) & ~inc) + 1;
+
+/* Try to extend an existing allocation. If the result of calling
+store_extend() is false, either there isn't room in the current memory block,
+or this string is not the top item on the dynamic store stack. We then have
+to get a new chunk of store and copy the old string. When building large
+strings, it is helpful to call store_release() on the old string, to release
+memory blocks that have become empty. (The block will be freed if the string
+is at its start.) However, we can do this only if we know that the old string
+was the last item on the dynamic memory stack. This is the case if it matches
+store_last_get. */
+
+if (!store_extend(g->s, oldsize, g->size))
+  g->s = store_newblock(g->s, g->size, p);
+}
+
+
+
 /* This function is used when building up strings of unknown length. Room is
 always left for a terminating zero to be added to the string that is being
 built. This function does not require the string that is being added to be NUL
@@ -1072,15 +1147,9 @@ sometimes called to extract parts of other strings.
 Arguments:
   string   points to the start of the string that is being built, or NULL
              if this is a new string that has no contents yet
-  size     points to a variable that holds the current capacity of the memory
-             block (updated if changed)
-  ptr      points to a variable that holds the offset at which to add
-             characters, updated to the new offset
   s        points to characters to add
   count    count of characters to add; must not exceed the length of s, if s
-             is a C string.  If -1 given, strlen(s) is used.
-
-If string is given as NULL, *size and *ptr should both be zero.
+             is a C string.
 
 Returns:   pointer to the start of the string, changed if copied for expansion.
            Note that a NUL is not added, though space is left for one. This is
@@ -1090,74 +1159,40 @@ Returns:   pointer to the start of the string, changed if copied for expansion.
 */
 /* coverity[+alloc] */
 
-uschar *
-string_catn(uschar *string, int *size, int *ptr, const uschar *s, int count)
+gstring *
+string_catn(gstring * g, const uschar *s, int count)
 {
-int p = *ptr;
+int p;
 
-if (p + count >= *size)
+if (!g)
   {
-  int oldsize = *size;
-
-  /* Mostly, string_cat() is used to build small strings of a few hundred
-  characters at most. There are times, however, when the strings are very much
-  longer (for example, a lookup that returns a vast number of alias addresses).
-  To try to keep things reasonable, we use increments whose size depends on the
-  existing length of the string. */
-
-  int inc = (oldsize < 4096)? 100 : 1024;
-  while (*size <= p + count) *size += inc;
-
-  /* New string */
-
-  if (string == NULL) string = store_get(*size);
-
-  /* Try to extend an existing allocation. If the result of calling
-  store_extend() is false, either there isn't room in the current memory block,
-  or this string is not the top item on the dynamic store stack. We then have
-  to get a new chunk of store and copy the old string. When building large
-  strings, it is helpful to call store_release() on the old string, to release
-  memory blocks that have become empty. (The block will be freed if the string
-  is at its start.) However, we can do this only if we know that the old string
-  was the last item on the dynamic memory stack. This is the case if it matches
-  store_last_get. */
-
-  else if (!store_extend(string, oldsize, *size))
-    {
-    BOOL release_ok = store_last_get[store_pool] == string;
-    uschar *newstring = store_get(*size);
-    memcpy(newstring, string, p);
-    if (release_ok) store_release(string);
-    string = newstring;
-    }
+  unsigned inc = count < 4096 ? 127 : 1023;
+  unsigned size = ((count + inc) &  ~inc) + 1;
+  g = string_get(size);
   }
 
+p = g->ptr;
+if (p + count >= g->size)
+  gstring_grow(g, p, count);
+
 /* Because we always specify the exact number of characters to copy, we can
 use memcpy(), which is likely to be more efficient than strncopy() because the
-latter has to check for zero bytes.
+latter has to check for zero bytes. */
 
-The Coverity annotation deals with the lack of correlated variable tracking;
-common use is a null string and zero size and pointer, on first use for a
-string being built. The "if" above then allocates, but Coverity assume that
-the "if" might not happen and whines for a null-deref done by the memcpy(). */
-
-/* coverity[deref_parm_field_in_call] : FALSE */
-memcpy(string + p, s, count);
-*ptr = p + count;
-return string;
+memcpy(g->s + p, s, count);
+g->ptr = p + count;
+return g;
 }
-
-
-uschar *
-string_cat(uschar *string, int *size, int *ptr, const uschar *s)
+ 
+ 
+gstring *
+string_cat(gstring *string, const uschar *s)
 {
-return string_catn(string, size, ptr, s, Ustrlen(s));
+return string_catn(string, s, Ustrlen(s));
 }
-#endif  /* COMPILE_UTILITY */
 
 
 
-#ifndef COMPILE_UTILITY
 /*************************************************
 *        Append strings to another string        *
 *************************************************/
@@ -1166,12 +1201,8 @@ return string_catn(string, size, ptr, s, Ustrlen(s));
 It calls string_cat() to do the dirty work.
 
 Arguments:
-  string   points to the start of the string that is being built, or NULL
+  string   expanding-string that is being built, or NULL
              if this is a new string that has no contents yet
-  size     points to a variable that holds the current capacity of the memory
-             block (updated if changed)
-  ptr      points to a variable that holds the offset at which to add
-             characters, updated to the new offset
   count    the number of strings to append
   ...      "count" uschar* arguments, which must be valid zero-terminated
              C strings
@@ -1180,17 +1211,16 @@ Returns:   pointer to the start of the string, changed if copied for expansion.
            The string is not zero-terminated - see string_cat() above.
 */
 
-uschar *
-string_append(uschar *string, int *size, int *ptr, int count, ...)
+__inline__ gstring *
+string_append(gstring *string, int count, ...)
 {
 va_list ap;
-int i;
 
 va_start(ap, count);
-for (i = 0; i < count; i++)
+while (count-- > 0)
   {
   uschar *t = va_arg(ap, uschar *);
-  string = string_cat(string, size, ptr, t);
+  string = string_cat(string, t);
   }
 va_end(ap);
 
@@ -1213,7 +1243,7 @@ as a va_list item.
 
 The formats are the usual printf() ones, with some omissions (never used) and
 three additions for strings: %S forces lower case, %T forces upper case, and
-%#s or %#S prints nothing for a NULL string. Without thr # "NULL" is printed
+%#s or %#S prints nothing for a NULL string. Without the # "NULL" is printed
 (useful in debugging). There is also the addition of %D and %M, which insert
 the date in the form used for datestamped log files.
 
@@ -1359,20 +1389,28 @@ while (*fp != 0)
     switch(length)
       {
       case L_SHORT:
-      case L_NORMAL:   sprintf(CS p, newformat, va_arg(ap, int)); break;
-      case L_LONG:     sprintf(CS p, newformat, va_arg(ap, long int)); break;
-      case L_LONGLONG: sprintf(CS p, newformat, va_arg(ap, LONGLONG_T)); break;
-      case L_SIZE:     sprintf(CS p, newformat, va_arg(ap, size_t)); break;
+      case L_NORMAL:   p += sprintf(CS p, newformat, va_arg(ap, int)); break;
+      case L_LONG:     p += sprintf(CS p, newformat, va_arg(ap, long int)); break;
+      case L_LONGLONG: p += sprintf(CS p, newformat, va_arg(ap, LONGLONG_T)); break;
+      case L_SIZE:     p += sprintf(CS p, newformat, va_arg(ap, size_t)); break;
       }
-    while (*p) p++;
     break;
 
     case 'p':
-    if (p >= last - 24) { yield = FALSE; goto END_FORMAT; }
-    strncpy(newformat, item_start, fp - item_start);
-    newformat[fp - item_start] = 0;
-    sprintf(CS p, newformat, va_arg(ap, void *));
-    while (*p) p++;
+      {
+      void * ptr;
+      if (p >= last - 24) { yield = FALSE; goto END_FORMAT; }
+      /* sprintf() saying "(nil)" for a null pointer seems unreliable.
+      Handle it explicitly. */
+      if ((ptr = va_arg(ap, void *)))
+	{
+	strncpy(newformat, item_start, fp - item_start);
+	newformat[fp - item_start] = 0;
+	p += sprintf(CS p, newformat, ptr);
+	}
+      else
+	p += sprintf(CS p, "(nil)");
+      }
     break;
 
     /* %f format is inherently insecure if the numbers that it may be
@@ -1392,10 +1430,9 @@ while (*fp != 0)
     strncpy(newformat, item_start, fp - item_start);
     newformat[fp-item_start] = 0;
     if (length == L_LONGDOUBLE)
-      sprintf(CS p, newformat, va_arg(ap, long double));
+      p += sprintf(CS p, newformat, va_arg(ap, long double));
     else
-      sprintf(CS p, newformat, va_arg(ap, double));
-    while (*p) p++;
+      p += sprintf(CS p, newformat, va_arg(ap, double));
     break;
 
     /* String types */