X-Git-Url: https://git.verplant.org/?a=blobdiff_plain;f=src%2Fdaemon%2Fcommon.c;h=d53f1ec0aa968f63a8130362047cf2b83458f05a;hb=afb38f31abd27d5b4ce08023f8bbbaeeb353c55f;hp=c6559a804e3b003c45e2566c466c7f5413b2d6f3;hpb=ee830b46965eac77e608d536c51d15062b9842bb;p=collectd.git

diff --git a/src/daemon/common.c b/src/daemon/common.c
index c6559a80..d53f1ec0 100644
--- a/src/daemon/common.c
+++ b/src/daemon/common.c
@@ -60,6 +60,10 @@
 # include <arpa/inet.h>
 #endif
 
+#ifdef HAVE_SYS_CAPABILITY_H
+# include <sys/capability.h>
+#endif
+
 #ifdef HAVE_LIBKSTAT
 extern kstat_ctl_t *kc;
 #endif
@@ -330,50 +334,60 @@ int strsplit (char *string, char **fields, size_t size)
 	return ((int) i);
 }
 
-int strjoin (char *buffer, size_t buffer_size,
-		char **fields, size_t fields_num,
-		const char *sep)
-{
-	size_t avail;
-	char *ptr;
-	size_t sep_len;
+int strjoin(char *buffer, size_t buffer_size, char **fields, size_t fields_num,
+            const char *sep) {
+  size_t avail = 0;
+  char *ptr = buffer;
+  size_t sep_len = 0;
 
-	if ((buffer_size < 1) || (fields_num == 0))
-		return (-1);
+  size_t buffer_req = 0;
 
-	memset (buffer, 0, buffer_size);
-	ptr = buffer;
-	avail = buffer_size - 1;
+  if (((fields_num != 0) && (fields == NULL)) ||
+      ((buffer_size != 0) && (buffer == NULL)))
+    return (-EINVAL);
 
-	sep_len = 0;
-	if (sep != NULL)
-		sep_len = strlen (sep);
+  if (buffer != NULL)
+    buffer[0] = 0;
 
-	for (size_t i = 0; i < fields_num; i++)
-	{
-		size_t field_len;
+  if (buffer_size != 0)
+    avail = buffer_size - 1;
 
-		if ((i > 0) && (sep_len > 0))
-		{
-			if (avail < sep_len)
-				return (-1);
+  if (sep != NULL)
+    sep_len = strlen(sep);
 
-			memcpy (ptr, sep, sep_len);
-			ptr += sep_len;
-			avail -= sep_len;
-		}
+  for (size_t i = 0; i < fields_num; i++) {
+    size_t field_len = strlen(fields[i]);
 
-		field_len = strlen (fields[i]);
-		if (avail < field_len)
-			return (-1);
+    if (i != 0)
+      buffer_req += sep_len;
+    buffer_req += field_len;
 
-		memcpy (ptr, fields[i], field_len);
-		ptr += field_len;
-		avail -= field_len;
-	}
+    if ((i != 0) && (sep_len > 0)) {
+      if (sep_len >= avail) {
+        /* prevent subsequent iterations from writing to the
+         * buffer. */
+        avail = 0;
+        continue;
+      }
 
-	assert (buffer[buffer_size - 1] == 0);
-	return ((int) strlen (buffer));
+      memcpy(ptr, sep, sep_len);
+
+      ptr += sep_len;
+      avail -= sep_len;
+    }
+
+    if (field_len > avail)
+      field_len = avail;
+
+    memcpy(ptr, fields[i], field_len);
+    ptr += field_len;
+
+    avail -= field_len;
+    if (ptr != NULL)
+      *ptr = 0;
+  }
+
+  return (int)buffer_req;
 }
 
 int escape_string (char *buffer, size_t buffer_size)
@@ -1668,3 +1682,52 @@ void strarray_free (char **array, size_t array_len) /* {{{ */
 		sfree (array[i]);
 	sfree (array);
 } /* }}} void strarray_free */
+
+#ifdef HAVE_SYS_CAPABILITY_H
+int check_capability (int capability) /* {{{ */
+{
+#ifdef _LINUX_CAPABILITY_VERSION_3
+	cap_user_header_t cap_header = calloc(1, sizeof (*cap_header));
+	if (cap_header == NULL)
+	{
+		ERROR("check_capability: calloc failed");
+		return (-1);
+	}
+
+	cap_user_data_t cap_data = calloc(1, sizeof (*cap_data));
+	if (cap_data == NULL)
+	{
+		ERROR("check_capability: calloc failed");
+		sfree(cap_header);
+		return (-1);
+	}
+
+	cap_header->pid = getpid();
+	cap_header->version = _LINUX_CAPABILITY_VERSION;
+	if (capget(cap_header, cap_data) < 0)
+	{
+		ERROR("check_capability: capget failed");
+		sfree(cap_header);
+		sfree(cap_data);
+		return (-1);
+	}
+
+	if ((cap_data->effective & (1 << capability)) == 0)
+	{
+		sfree(cap_header);
+		sfree(cap_data);
+		return (-1);
+	}
+	else
+	{
+		sfree(cap_header);
+		sfree(cap_data);
+		return (0);
+	}
+#else
+	WARNING ("check_capability: unsupported capability implementation. "
+	    "Some plugin(s) may require elevated privileges to work properly.");
+	return (0);
+#endif /* _LINUX_CAPABILITY_VERSION_3 */
+} /* }}} int check_capability */
+#endif /* HAVE_SYS_CAPABILITY_H */