X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Fdaemon%2Futils_subst.c;h=1bc28f724ea22e927e6981b09d28fd0d8de2bf8c;hb=4d86011a91b7fe05fd5f4d84fa88c19d8c031110;hp=2f28eb9b141fabbdaf452b227727dfa3f1b40bd5;hpb=6258e772d808f4e76ea8e23d9e2750cfc7e6c60d;p=collectd.git

diff --git a/src/daemon/utils_subst.c b/src/daemon/utils_subst.c
index 2f28eb9b..1bc28f72 100644
--- a/src/daemon/utils_subst.c
+++ b/src/daemon/utils_subst.c
@@ -29,35 +29,64 @@
  */
 
 #include "collectd.h"
+
 #include "common.h"
+#include "utils_subst.h"
 
-char *subst (char *buf, size_t buflen, const char *string, int off1, int off2,
+char *subst (char *buf, size_t buflen, const char *string, size_t off1, size_t off2,
 		const char *replacement)
 {
-	char  *buf_ptr = buf;
-	size_t len     = buflen;
+	char *out = buf;
+
+	char const *front;
+	char const *back;
+	size_t front_len;
+	size_t replacement_len;
+	size_t back_len;
+
+	if ((NULL == buf) || (0 == buflen) || (NULL == string) || (NULL == replacement))
+		return NULL;
 
-	if ((NULL == buf) || (0 >= buflen) || (NULL == string)
-			|| (0 > off1) || (0 > off2) || (off1 > off2)
-			|| (NULL == replacement))
+	size_t string_len = strlen (string);
+	if ((off1 > string_len) || (off2 > string_len) || (off1 > off2))
 		return NULL;
 
-	sstrncpy (buf_ptr, string,
-			((size_t)off1 + 1 > buflen) ? buflen : (size_t)off1 + 1);
-	buf_ptr += off1;
-	len     -= off1;
+	front = string;
+	back = string + off2;
+	front_len = off1;
+	replacement_len = strlen (replacement);
+	back_len = strlen (back);
+
+	if (front_len >= buflen) {
+		front_len = buflen - 1;
+		replacement_len = 0;
+		back_len = 0;
+	} else if ((front_len + replacement_len) >= buflen) {
+		replacement_len = buflen - (front_len + 1);
+		back_len = 0;
+	} else if ((front_len + replacement_len + back_len) >= buflen) {
+		back_len = buflen - (front_len + replacement_len + 1);
+	} else {
+		buflen = front_len + replacement_len + back_len + 1;
+	}
+	assert ((front_len + replacement_len + back_len) == (buflen - 1));
 
-	if (0 >= len)
-		return buf;
+	if (front_len != 0) {
+		sstrncpy (out, front, front_len + 1);
+		out += front_len;
+	}
 
-	sstrncpy (buf_ptr, replacement, len);
-	buf_ptr += strlen (replacement);
-	len     -= strlen (replacement);
+	if (replacement_len != 0) {
+		sstrncpy (out, replacement, replacement_len + 1);
+		out += replacement_len;
+	}
 
-	if (0 >= len)
-		return buf;
+	if (back_len != 0) {
+		sstrncpy (out, back, back_len + 1);
+		out += back_len;
+	}
 
-	sstrncpy (buf_ptr, string + off2, len);
+	out[0] = 0;
 	return buf;
 } /* subst */
 
@@ -74,7 +103,7 @@ char *asubst (const char *string, int off1, int off2, const char *replacement)
 
 	len = off1 + strlen (replacement) + strlen (string) - off2 + 1;
 
-	buf = (char *)malloc (len);
+	buf = malloc (len);
 	if (NULL == buf)
 		return NULL;
 
@@ -87,7 +116,6 @@ char *asubst (const char *string, int off1, int off2, const char *replacement)
 char *subst_string (char *buf, size_t buflen, const char *string,
 		const char *needle, const char *replacement)
 {
-	char *temp;
 	size_t needle_len;
 	size_t i;
 
@@ -95,19 +123,13 @@ char *subst_string (char *buf, size_t buflen, const char *string,
 			|| (needle == NULL) || (replacement == NULL))
 		return (NULL);
 
-	temp = (char *) malloc (buflen);
-	if (temp == NULL)
-	{
-		ERROR ("subst_string: malloc failed.");
-		return (NULL);
-	}
-
 	needle_len = strlen (needle);
-	strncpy (buf, string, buflen);
+	sstrncpy (buf, string, buflen);
 
 	/* Limit the loop to prevent endless loops. */
 	for (i = 0; i < buflen; i++)
 	{
+		char temp[buflen];
 		char *begin_ptr;
 		size_t begin;
 
@@ -141,7 +163,6 @@ char *subst_string (char *buf, size_t buflen, const char *string,
 				i, string, needle, replacement);
 	}
 
-	sfree (temp);
 	return (buf);
 } /* char *subst_string */