X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=52fb25dbe7202a3af44d1548ea1b021b2ad7ee65;hp=766f224c7e167118d30dbd99c6b32595b4fe99e4;hb=77e7fddf47ca285c4d4d161745ddaf2bca6b46b2;hpb=a596dcb9418fb17d2ad247630efb5d764a7b6abe

diff --git a/src/common/utils.c b/src/common/utils.c
index 766f224c7..52fb25dbe 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -24,7 +24,6 @@
 #include <fcntl.h>
 #include <limits.h>
 #include <stdlib.h>
-#include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <unistd.h>
@@ -37,6 +36,7 @@
 #include <common/common.h>
 #include <common/runas.h>
 #include <common/compat/getenv.h>
+#include <common/compat/string.h>
 
 #include "utils.h"
 #include "defaults.h"
@@ -55,7 +55,7 @@
 LTTNG_HIDDEN
 char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
 {
-	char *cut_path, *try_path = NULL, *try_path_prev = NULL;
+	char *cut_path = NULL, *try_path = NULL, *try_path_prev = NULL;
 	const char *next, *prev, *end;
 
 	/* Safety net */
@@ -92,9 +92,9 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
 		}
 
 		/* Cut the part we will be trying to resolve */
-		cut_path = strndup(path, next - path);
+		cut_path = lttng_strndup(path, next - path);
 		if (cut_path == NULL) {
-			PERROR("strndup");
+			PERROR("lttng_strndup");
 			goto error;
 		}
 
@@ -124,7 +124,8 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
 
 		/* Free the allocated memory */
 		free(cut_path);
-	};
+		cut_path = NULL;
+	}
 
 	/* Allocate memory for the resolved path if necessary */
 	if (resolved_path == NULL) {
@@ -161,6 +162,8 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
 		/* Free the allocated memory */
 		free(cut_path);
 		free(try_path_prev);
+		cut_path = NULL;
+		try_path_prev = NULL;
 	/*
 	 * Else, we just copy the path in our resolved_path to
 	 * return it as is
@@ -174,6 +177,7 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
 
 error:
 	free(resolved_path);
+	free(cut_path);
 	return NULL;
 }
 
@@ -226,9 +230,9 @@ char *utils_expand_path(const char *path)
 	while ((next = strstr(absolute_path, "/./"))) {
 
 		/* We prepare the start_path not containing it */
-		start_path = strndup(absolute_path, next - absolute_path);
+		start_path = lttng_strndup(absolute_path, next - absolute_path);
 		if (!start_path) {
-			PERROR("strndup");
+			PERROR("lttng_strndup");
 			goto error;
 		}
 		/* And we concatenate it with the part after this string */
@@ -246,9 +250,9 @@ char *utils_expand_path(const char *path)
 		}
 
 		/* Then we prepare the start_path not containing it */
-		start_path = strndup(absolute_path, previous - absolute_path);
+		start_path = lttng_strndup(absolute_path, previous - absolute_path);
 		if (!start_path) {
-			PERROR("strndup");
+			PERROR("lttng_strndup");
 			goto error;
 		}
 
@@ -500,11 +504,13 @@ int utils_create_lock_file(const char *filepath)
 {
 	int ret;
 	int fd;
+	struct flock lock;
 
 	assert(filepath);
 
-	fd = open(filepath, O_CREAT,
-		O_WRONLY | S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
+	memset(&lock, 0, sizeof(lock));
+	fd = open(filepath, O_CREAT | O_WRONLY, S_IRUSR | S_IWUSR |
+		S_IRGRP | S_IWGRP);
 	if (fd < 0) {
 		PERROR("open lock file %s", filepath);
 		ret = -1;
@@ -516,8 +522,12 @@ int utils_create_lock_file(const char *filepath)
 	 * already a process using the same lock file running
 	 * and we should exit.
 	 */
-	ret = flock(fd, LOCK_EX | LOCK_NB);
-	if (ret) {
+	lock.l_whence = SEEK_SET;
+	lock.l_type = F_WRLCK;
+
+	ret = fcntl(fd, F_SETLK, &lock);
+	if (ret == -1) {
+		PERROR("fcntl lock file");
 		ERR("Could not get lock file %s, another instance is running.",
 			filepath);
 		if (close(fd)) {
@@ -532,12 +542,42 @@ error:
 }
 
 /*
- * Recursively create directory using the given path and mode.
+ * Create directory using the given path and mode.
  *
  * On success, return 0 else a negative error code.
  */
 LTTNG_HIDDEN
-int utils_mkdir_recursive(const char *path, mode_t mode)
+int utils_mkdir(const char *path, mode_t mode, int uid, int gid)
+{
+	int ret;
+
+	if (uid < 0 || gid < 0) {
+		ret = mkdir(path, mode);
+	} else {
+		ret = run_as_mkdir(path, mode, uid, gid);
+	}
+	if (ret < 0) {
+		if (errno != EEXIST) {
+			PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL",
+					uid, gid);
+		} else {
+			ret = 0;
+		}
+	}
+
+	return ret;
+}
+
+/*
+ * Internal version of mkdir_recursive. Runs as the current user.
+ * Don't call directly; use utils_mkdir_recursive().
+ *
+ * This function is ominously marked as "unsafe" since it should only
+ * be called by a caller that has transitioned to the uid and gid under which
+ * the directory creation should occur.
+ */
+LTTNG_HIDDEN
+int _utils_mkdir_recursive_unsafe(const char *path, mode_t mode)
 {
 	char *p, tmp[PATH_MAX];
 	size_t len;
@@ -582,7 +622,7 @@ int utils_mkdir_recursive(const char *path, mode_t mode)
 	ret = mkdir(tmp, mode);
 	if (ret < 0) {
 		if (errno != EEXIST) {
-			PERROR("mkdir recursive last piece");
+			PERROR("mkdir recursive last element");
 			ret = -errno;
 		} else {
 			ret = 0;
@@ -594,20 +634,44 @@ error:
 }
 
 /*
- * Create the stream tracefile on disk.
+ * Recursively create directory using the given path and mode, under the
+ * provided uid and gid.
  *
- * Return 0 on success or else a negative value.
+ * On success, return 0 else a negative error code.
  */
 LTTNG_HIDDEN
-int utils_create_stream_file(const char *path_name, char *file_name, uint64_t size,
-		uint64_t count, int uid, int gid, char *suffix)
+int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
 {
-	int ret, out_fd, flags, mode;
-	char full_path[PATH_MAX], *path_name_suffix = NULL, *path;
-	char *extra = NULL;
+	int ret;
+
+	if (uid < 0 || gid < 0) {
+		/* Run as current user. */
+		ret = _utils_mkdir_recursive_unsafe(path, mode);
+	} else {
+		ret = run_as_mkdir_recursive(path, mode, uid, gid);
+	}
+	if (ret < 0) {
+		PERROR("mkdir %s, uid %d, gid %d", path ? path : "NULL",
+				uid, gid);
+	}
 
-	assert(path_name);
-	assert(file_name);
+	return ret;
+}
+
+/*
+ * path is the output parameter. It needs to be PATH_MAX len.
+ *
+ * Return 0 on success or else a negative value.
+ */
+static int utils_stream_file_name(char *path,
+		const char *path_name, const char *file_name,
+		uint64_t size, uint64_t count,
+		const char *suffix)
+{
+	int ret;
+	char full_path[PATH_MAX];
+	char *path_name_suffix = NULL;
+	char *extra = NULL;
 
 	ret = snprintf(full_path, sizeof(full_path), "%s/%s",
 			path_name, file_name);
@@ -630,8 +694,8 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si
 	}
 
 	/*
-	 * If we split the trace in multiple files, we have to add the count at the
-	 * end of the tracefile name
+	 * If we split the trace in multiple files, we have to add the count at
+	 * the end of the tracefile name.
 	 */
 	if (extra) {
 		ret = asprintf(&path_name_suffix, "%s%s", full_path, extra);
@@ -639,9 +703,37 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si
 			PERROR("Allocating path name with extra string");
 			goto error_free_suffix;
 		}
-		path = path_name_suffix;
+		strncpy(path, path_name_suffix, PATH_MAX - 1);
+		path[PATH_MAX - 1] = '\0';
 	} else {
-		path = full_path;
+		strncpy(path, full_path, PATH_MAX - 1);
+	}
+	path[PATH_MAX - 1] = '\0';
+	ret = 0;
+
+	free(path_name_suffix);
+error_free_suffix:
+	free(extra);
+error:
+	return ret;
+}
+
+/*
+ * Create the stream file on disk.
+ *
+ * Return 0 on success or else a negative value.
+ */
+LTTNG_HIDDEN
+int utils_create_stream_file(const char *path_name, char *file_name, uint64_t size,
+		uint64_t count, int uid, int gid, char *suffix)
+{
+	int ret, flags, mode;
+	char path[PATH_MAX];
+
+	ret = utils_stream_file_name(path, path_name, file_name,
+			size, count, suffix);
+	if (ret < 0) {
+		goto error;
 	}
 
 	flags = O_WRONLY | O_CREAT | O_TRUNC;
@@ -649,21 +741,44 @@ int utils_create_stream_file(const char *path_name, char *file_name, uint64_t si
 	mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP;
 
 	if (uid < 0 || gid < 0) {
-		out_fd = open(path, flags, mode);
+		ret = open(path, flags, mode);
 	} else {
-		out_fd = run_as_open(path, flags, mode, uid, gid);
+		ret = run_as_open(path, flags, mode, uid, gid);
 	}
-	if (out_fd < 0) {
+	if (ret < 0) {
 		PERROR("open stream path %s", path);
-		goto error_open;
 	}
-	ret = out_fd;
+error:
+	return ret;
+}
 
-error_open:
-	free(path_name_suffix);
-error_free_suffix:
-	free(extra);
+/*
+ * Unlink the stream tracefile from disk.
+ *
+ * Return 0 on success or else a negative value.
+ */
+LTTNG_HIDDEN
+int utils_unlink_stream_file(const char *path_name, char *file_name, uint64_t size,
+		uint64_t count, int uid, int gid, char *suffix)
+{
+	int ret;
+	char path[PATH_MAX];
+
+	ret = utils_stream_file_name(path, path_name, file_name,
+			size, count, suffix);
+	if (ret < 0) {
+		goto error;
+	}
+	if (uid < 0 || gid < 0) {
+		ret = unlink(path);
+	} else {
+		ret = run_as_unlink(path, uid, gid);
+	}
+	if (ret < 0) {
+		goto error;
+	}
 error:
+	DBG("utils_unlink_stream_file %s returns %d", path, ret);
 	return ret;
 }
 
@@ -693,7 +808,25 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
 	}
 
 	if (count > 0) {
+		/*
+		 * In tracefile rotation, for the relay daemon we need
+		 * to unlink the old file if present, because it may
+		 * still be open in reading by the live thread, and we
+		 * need to ensure that we do not overwrite the content
+		 * between get_index and get_packet. Since we have no
+		 * way to verify integrity of the data content compared
+		 * to the associated index, we need to ensure the reader
+		 * has exclusive access to the file content, and that
+		 * the open of the data file is performed in get_index.
+		 * Unlinking the old file rather than overwriting it
+		 * achieves this.
+		 */
 		*new_count = (*new_count + 1) % count;
+		ret = utils_unlink_stream_file(path_name, file_name,
+				size, *new_count, uid, gid, 0);
+		if (ret < 0 && errno != ENOENT) {
+			goto error;
+		}
 	} else {
 		(*new_count)++;
 	}
@@ -1070,6 +1203,7 @@ LTTNG_HIDDEN
 int utils_recursive_rmdir(const char *path)
 {
 	DIR *dir;
+	size_t path_len;
 	int dir_fd, ret = 0, closeret, is_empty = 1;
 	struct dirent *entry;
 
@@ -1085,13 +1219,34 @@ int utils_recursive_rmdir(const char *path)
 		return -1;
 	}
 
+	path_len = strlen(path);
 	while ((entry = readdir(dir))) {
 		if (!strcmp(entry->d_name, ".")
 				|| !strcmp(entry->d_name, ".."))
 			continue;
-		switch (entry->d_type) {
-		case DT_DIR:
-		{
+
+		struct stat st;
+		size_t name_len;
+		char filename[PATH_MAX];
+
+		name_len = strlen(entry->d_name);
+		if (path_len + name_len + 2 > sizeof(filename)) {
+			ERR("Failed to remove file: path name too long (%s/%s)",
+				path, entry->d_name);
+			continue;
+		}
+		if (snprintf(filename, sizeof(filename), "%s/%s",
+				path, entry->d_name) < 0) {
+			ERR("Failed to format path.");
+			continue;
+		}
+
+		if (stat(filename, &st)) {
+			PERROR("stat");
+			continue;
+		}
+
+		if (S_ISDIR(st.st_mode)) {
 			char subpath[PATH_MAX];
 
 			strncpy(subpath, path, PATH_MAX);
@@ -1103,12 +1258,9 @@ int utils_recursive_rmdir(const char *path)
 			if (utils_recursive_rmdir(subpath)) {
 				is_empty = 0;
 			}
-			break;
-		}
-		case DT_REG:
+		} else if (S_ISREG(st.st_mode)) {
 			is_empty = 0;
-			break;
-		default:
+		} else {
 			ret = -EINVAL;
 			goto end;
 		}