X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=libudev%2Flibudev-util.c;h=030b78cd224382ff8c2de359b541c766a579443f;hb=c11f89b61a7872f640a15292a21c43504ce664da;hp=61cd963421a4842db897318b0aa83537ef29aac5;hpb=32ecabb15d76bd9db8f7d15dcd39807383a93934;p=elogind.git

diff --git a/libudev/libudev-util.c b/libudev/libudev-util.c
index 61cd96342..030b78cd2 100644
--- a/libudev/libudev-util.c
+++ b/libudev/libudev-util.c
@@ -31,7 +31,7 @@ static ssize_t get_sys_link(struct udev *udev, const char *slink, const char *sy
 
 	util_strscpyl(path, sizeof(path), syspath, "/", slink, NULL);
 	len = readlink(path, path, sizeof(path));
-	if (len < 0 || len >= (ssize_t) sizeof(path))
+	if (len <= 0 || len == (ssize_t)sizeof(path))
 		return -1;
 	path[len] = '\0';
 	pos = strrchr(path, '/');
@@ -87,13 +87,13 @@ int util_log_priority(const char *priority)
 	int prio;
 
 	prio = strtol(priority, &endptr, 10);
-	if (endptr[0] == '\0')
+	if (endptr[0] == '\0' || isspace(endptr[0]))
 		return prio;
 	if (strncmp(priority, "err", 3) == 0)
 		return LOG_ERR;
-	if (strcmp(priority, "info") == 0)
+	if (strncmp(priority, "info", 4) == 0)
 		return LOG_INFO;
-	if (strcmp(priority, "debug") == 0)
+	if (strncmp(priority, "debug", 5) == 0)
 		return LOG_DEBUG;
 	return 0;
 }
@@ -448,55 +448,107 @@ int udev_util_encode_string(const char *str, char *str_enc, size_t len)
 {
 	size_t i, j;
 
-	if (str == NULL || str_enc == NULL || len == 0)
+	if (str == NULL || str_enc == NULL)
 		return -1;
 
-	str_enc[0] = '\0';
 	for (i = 0, j = 0; str[i] != '\0'; i++) {
 		int seqlen;
 
 		seqlen = utf8_encoded_valid_unichar(&str[i]);
 		if (seqlen > 1) {
+			if (len-j < (size_t)seqlen)
+				goto err;
 			memcpy(&str_enc[j], &str[i], seqlen);
 			j += seqlen;
 			i += (seqlen-1);
 		} else if (str[i] == '\\' || !is_whitelisted(str[i], NULL)) {
+			if (len-j < 4)
+				goto err;
 			sprintf(&str_enc[j], "\\x%02x", (unsigned char) str[i]);
 			j += 4;
 		} else {
+			if (len-j < 1)
+				goto err;
 			str_enc[j] = str[i];
 			j++;
 		}
-		if (j+3 >= len)
-			goto err;
 	}
+	if (len-j < 1)
+		goto err;
 	str_enc[j] = '\0';
 	return 0;
 err:
 	return -1;
 }
 
-void util_set_fd_cloexec(int fd)
+/*
+ * http://sites.google.com/site/murmurhash/
+ *
+ * All code is released to the public domain. For business purposes,
+ * Murmurhash is under the MIT license.
+ *
+ */
+static unsigned int murmur_hash2(const char *key, int len, unsigned int seed)
 {
-	int flags;
-
-	flags = fcntl(fd, F_GETFD);
-	if (flags < 0)
-		flags = FD_CLOEXEC;
-	else
-		flags |= FD_CLOEXEC;
-	fcntl(fd, F_SETFD, flags);
+	/*
+	 *  'm' and 'r' are mixing constants generated offline.
+	 *  They're not really 'magic', they just happen to work well.
+	 */
+	const unsigned int m = 0x5bd1e995;
+	const int r = 24;
+
+	/* initialize the hash to a 'random' value */
+	unsigned int h = seed ^ len;
+
+	/* mix 4 bytes at a time into the hash */
+	const unsigned char * data = (const unsigned char *)key;
+
+	while(len >= 4) {
+		unsigned int k = *(unsigned int *)data;
+
+		k *= m; 
+		k ^= k >> r; 
+		k *= m; 
+		h *= m; 
+		h ^= k;
+
+		data += 4;
+		len -= 4;
+	}
+
+	/* handle the last few bytes of the input array */
+	switch(len) {
+	case 3:
+		h ^= data[2] << 16;
+	case 2:
+		h ^= data[1] << 8;
+	case 1:
+		h ^= data[0];
+		h *= m;
+	};
+
+	/* do a few final mixes of the hash to ensure the last few bytes are well-incorporated */
+	h ^= h >> 13;
+	h *= m;
+	h ^= h >> 15;
+
+	return h;
 }
 
 unsigned int util_string_hash32(const char *str)
 {
-	unsigned int hash = 0;
+	return murmur_hash2(str, strlen(str), 0);
+}
 
-	while (str[0] != '\0') {
-		hash += str[0] << 4;
-		hash += str[0] >> 4;
-		hash *= 11;
-		str++;
-	}
-	return hash;
+/* get a bunch of bit numbers out of the hash, and set the bits in our bit field */
+uint64_t util_string_bloom64(const char *str)
+{
+	uint64_t bits = 0;
+	unsigned int hash = util_string_hash32(str);
+
+	bits |= 1LLU << (hash & 63);
+	bits |= 1LLU << ((hash >> 6) & 63);
+	bits |= 1LLU << ((hash >> 12) & 63);
+	bits |= 1LLU << ((hash >> 18) & 63);
+	return bits;
 }