X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Futils.c;h=db2ed8e7d11dee928a6f96be4167a94669f015c6;hp=ea1e5db0ee31dd192d7661dd2537f9a9c5c30298;hb=d77dded285b058e4242c8a3d2233f80e725ceefc;hpb=8db0dc005c98126fb0e6ede59a695e399ad31e01

diff --git a/src/common/utils.c b/src/common/utils.c
index ea1e5db0e..db2ed8e7d 100644
--- a/src/common/utils.c
+++ b/src/common/utils.c
@@ -18,6 +18,7 @@
  */
 
 #define _GNU_SOURCE
+#define _LGPL_SOURCE
 #include <assert.h>
 #include <ctype.h>
 #include <fcntl.h>
@@ -28,11 +29,14 @@
 #include <sys/types.h>
 #include <unistd.h>
 #include <inttypes.h>
-#include <regex.h>
 #include <grp.h>
+#include <pwd.h>
+#include <sys/file.h>
+#include <dirent.h>
 
 #include <common/common.h>
 #include <common/runas.h>
+#include <common/compat/getenv.h>
 
 #include "utils.h"
 #include "defaults.h"
@@ -89,6 +93,10 @@ 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);
+		if (cut_path == NULL) {
+			PERROR("strndup");
+			goto error;
+		}
 
 		/* Try to resolve this part */
 		try_path = realpath((char *)cut_path, NULL);
@@ -142,6 +150,10 @@ char *utils_partial_realpath(const char *path, char *resolved_path, size_t size)
 		 * path are pointers for the same memory space
 		 */
 		cut_path = strdup(prev);
+		if (cut_path == NULL) {
+			PERROR("strdup");
+			goto error;
+		}
 
 		/* Concatenate the strings */
 		snprintf(resolved_path, size, "%s%s", try_path_prev, cut_path);
@@ -215,7 +227,10 @@ char *utils_expand_path(const char *path)
 
 		/* We prepare the start_path not containing it */
 		start_path = strndup(absolute_path, next - absolute_path);
-
+		if (!start_path) {
+			PERROR("strndup");
+			goto error;
+		}
 		/* And we concatenate it with the part after this string */
 		snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 2);
 
@@ -232,6 +247,10 @@ char *utils_expand_path(const char *path)
 
 		/* Then we prepare the start_path not containing it */
 		start_path = strndup(absolute_path, previous - absolute_path);
+		if (!start_path) {
+			PERROR("strndup");
+			goto error;
+		}
 
 		/* And we concatenate it with the part after the '/../' */
 		snprintf(absolute_path, PATH_MAX, "%s%s", start_path, next + 4);
@@ -460,21 +479,95 @@ int utils_create_pid_file(pid_t pid, const char *filepath)
 	ret = fprintf(fp, "%d\n", pid);
 	if (ret < 0) {
 		PERROR("fprintf pid file");
+		goto error;
 	}
 
-	fclose(fp);
+	if (fclose(fp)) {
+		PERROR("fclose");
+	}
 	DBG("Pid %d written in file %s", pid, filepath);
+	ret = 0;
 error:
 	return ret;
 }
 
 /*
- * Recursively create directory using the given path and mode.
+ * Create lock file to the given path and filename.
+ * Returns the associated file descriptor, -1 on error.
+ */
+LTTNG_HIDDEN
+int utils_create_lock_file(const char *filepath)
+{
+	int ret;
+	int fd;
+
+	assert(filepath);
+
+	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;
+		goto error;
+	}
+
+	/*
+	 * Attempt to lock the file. If this fails, there is
+	 * already a process using the same lock file running
+	 * and we should exit.
+	 */
+	ret = flock(fd, LOCK_EX | LOCK_NB);
+	if (ret) {
+		ERR("Could not get lock file %s, another instance is running.",
+			filepath);
+		if (close(fd)) {
+			PERROR("close lock file");
+		}
+		fd = ret;
+		goto error;
+	}
+
+error:
+	return fd;
+}
+
+/*
+ * 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;
@@ -519,7 +612,7 @@ 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;
@@ -530,8 +623,34 @@ error:
 	return ret;
 }
 
+/*
+ * Recursively create directory using the given path and mode, under the
+ * provided uid and gid.
+ *
+ * On success, return 0 else a negative error code.
+ */
+LTTNG_HIDDEN
+int utils_mkdir_recursive(const char *path, mode_t mode, int uid, int gid)
+{
+	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);
+	}
+
+	return ret;
+}
+
 /*
  * Create the stream tracefile on disk.
+ * path is the output parameter. It needs to be PATH_MAX len.
  *
  * Return 0 on success or else a negative value.
  */
@@ -649,42 +768,10 @@ error:
 	return ret;
 }
 
-/**
- * Prints the error message corresponding to a regex error code.
- *
- * @param errcode	The error code.
- * @param regex		The regex object that produced the error code.
- */
-static void regex_print_error(int errcode, regex_t *regex)
-{
-	/* Get length of error message and allocate accordingly */
-	size_t length;
-	char *buffer;
-
-	assert(regex != NULL);
-
-	length = regerror(errcode, regex, NULL, 0);
-	if (length == 0) {
-		ERR("regerror returned a length of 0");
-		return;
-	}
-
-	buffer = zmalloc(length);
-	if (!buffer) {
-		ERR("regex_print_error: zmalloc failed");
-		return;
-	}
-
-	/* Get and print error message */
-	regerror(errcode, regex, buffer, length);
-	ERR("regex error: %s\n", buffer);
-	free(buffer);
-
-}
 
 /**
  * Parse a string that represents a size in human readable format. It
- * supports decimal integers suffixed by 'k', 'M' or 'G'.
+ * supports decimal integers suffixed by 'k', 'K', 'M' or 'G'.
  *
  * The suffix multiply the integer by:
  * 'k': 1024
@@ -692,83 +779,90 @@ static void regex_print_error(int errcode, regex_t *regex)
  * 'G': 1024^3
  *
  * @param str	The string to parse.
- * @param size	Pointer to a size_t that will be filled with the
+ * @param size	Pointer to a uint64_t that will be filled with the
  *		resulting size.
  *
  * @return 0 on success, -1 on failure.
  */
 LTTNG_HIDDEN
-int utils_parse_size_suffix(char *str, uint64_t *size)
+int utils_parse_size_suffix(const char * const str, uint64_t * const size)
 {
-	regex_t regex;
 	int ret;
-	const int nmatch = 3;
-	regmatch_t suffix_match, matches[nmatch];
-	unsigned long long base_size;
+	uint64_t base_size;
 	long shift = 0;
+	const char *str_end;
+	char *num_end;
 
 	if (!str) {
-		return 0;
-	}
-
-	/* Compile regex */
-	ret = regcomp(&regex, "^\\(0x\\)\\{0,1\\}[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0);
-	if (ret != 0) {
-		regex_print_error(ret, &regex);
+		DBG("utils_parse_size_suffix: received a NULL string.");
 		ret = -1;
 		goto end;
 	}
 
-	/* Match regex */
-	ret = regexec(&regex, str, nmatch, matches, 0);
-	if (ret != 0) {
+	/* strtoull will accept a negative number, but we don't want to. */
+	if (strchr(str, '-') != NULL) {
+		DBG("utils_parse_size_suffix: invalid size string, should not contain '-'.");
 		ret = -1;
-		goto free;
+		goto end;
 	}
 
-	/* There is a match ! */
+	/* str_end will point to the \0 */
+	str_end = str + strlen(str);
 	errno = 0;
-	base_size = strtoull(str, NULL, 0);
+	base_size = strtoull(str, &num_end, 0);
 	if (errno != 0) {
-		PERROR("strtoull");
+		PERROR("utils_parse_size_suffix strtoull");
 		ret = -1;
-		goto free;
+		goto end;
 	}
 
-	/* Check if there is a suffix */
-	suffix_match = matches[2];
-	if (suffix_match.rm_eo - suffix_match.rm_so == 1) {
-		switch (*(str + suffix_match.rm_so)) {
-		case 'K':
-		case 'k':
-			shift = KIBI_LOG2;
-			break;
-		case 'M':
-			shift = MEBI_LOG2;
-			break;
-		case 'G':
-			shift = GIBI_LOG2;
-			break;
-		default:
-			ERR("parse_human_size: invalid suffix");
-			ret = -1;
-			goto free;
-		}
+	if (num_end == str) {
+		/* strtoull parsed nothing, not good. */
+		DBG("utils_parse_size_suffix: strtoull had nothing good to parse.");
+		ret = -1;
+		goto end;
+	}
+
+	/* Check if a prefix is present. */
+	switch (*num_end) {
+	case 'G':
+		shift = GIBI_LOG2;
+		num_end++;
+		break;
+	case 'M': /*  */
+		shift = MEBI_LOG2;
+		num_end++;
+		break;
+	case 'K':
+	case 'k':
+		shift = KIBI_LOG2;
+		num_end++;
+		break;
+	case '\0':
+		break;
+	default:
+		DBG("utils_parse_size_suffix: invalid suffix.");
+		ret = -1;
+		goto end;
+	}
+
+	/* Check for garbage after the valid input. */
+	if (num_end != str_end) {
+		DBG("utils_parse_size_suffix: Garbage after size string.");
+		ret = -1;
+		goto end;
 	}
 
 	*size = base_size << shift;
 
 	/* Check for overflow */
 	if ((*size >> shift) != base_size) {
-		ERR("parse_size_suffix: oops, overflow detected.");
+		DBG("utils_parse_size_suffix: oops, overflow detected.");
 		ret = -1;
-		goto free;
+		goto end;
 	}
 
 	ret = 0;
-
-free:
-	regfree(&regex);
 end:
 	return ret;
 }
@@ -847,11 +941,88 @@ LTTNG_HIDDEN
 char *utils_get_home_dir(void)
 {
 	char *val = NULL;
-	val = getenv(DEFAULT_LTTNG_HOME_ENV_VAR);
+	struct passwd *pwd;
+
+	val = lttng_secure_getenv(DEFAULT_LTTNG_HOME_ENV_VAR);
 	if (val != NULL) {
-		return val;
+		goto end;
+	}
+	val = lttng_secure_getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR);
+	if (val != NULL) {
+		goto end;
+	}
+
+	/* Fallback on the password file entry. */
+	pwd = getpwuid(getuid());
+	if (!pwd) {
+		goto end;
+	}
+	val = pwd->pw_dir;
+
+	DBG3("Home directory is '%s'", val);
+
+end:
+	return val;
+}
+
+/**
+ * Get user's home directory. Dynamically allocated, must be freed
+ * by the caller.
+ */
+LTTNG_HIDDEN
+char *utils_get_user_home_dir(uid_t uid)
+{
+	struct passwd pwd;
+	struct passwd *result;
+	char *home_dir = NULL;
+	char *buf = NULL;
+	long buflen;
+	int ret;
+
+	buflen = sysconf(_SC_GETPW_R_SIZE_MAX);
+	if (buflen == -1) {
+		goto end;
+	}
+retry:
+	buf = zmalloc(buflen);
+	if (!buf) {
+		goto end;
+	}
+
+	ret = getpwuid_r(uid, &pwd, buf, buflen, &result);
+	if (ret || !result) {
+		if (ret == ERANGE) {
+			free(buf);
+			buflen *= 2;
+			goto retry;
+		}
+		goto end;
 	}
-	return getenv(DEFAULT_LTTNG_FALLBACK_HOME_ENV_VAR);
+
+	home_dir = strdup(pwd.pw_dir);
+end:
+	free(buf);
+	return home_dir;
+}
+
+/*
+ * Obtain the value of LTTNG_KMOD_PROBES environment variable, if exists.
+ * Otherwise returns NULL.
+ */
+LTTNG_HIDDEN
+char *utils_get_kmod_probes_list(void)
+{
+	return lttng_secure_getenv(DEFAULT_LTTNG_KMOD_PROBES);
+}
+
+/*
+ * Obtain the value of LTTNG_EXTRA_KMOD_PROBES environment variable, if
+ * exists. Otherwise returns NULL.
+ */
+LTTNG_HIDDEN
+char *utils_get_extra_kmod_probes_list(void)
+{
+	return lttng_secure_getenv(DEFAULT_LTTNG_EXTRA_KMOD_PROBES);
 }
 
 /*
@@ -874,7 +1045,7 @@ size_t utils_get_current_time_str(const char *format, char *dst, size_t len)
 	timeinfo = localtime(&rawtime);
 	ret = strftime(dst, len, format, timeinfo);
 	if (ret == 0) {
-		ERR("Unable to strftime with format %s at dst %p of len %lu", format,
+		ERR("Unable to strftime with format %s at dst %p of len %zu", format,
 				dst, len);
 	}
 
@@ -935,12 +1106,77 @@ char *utils_generate_optstring(const struct option *long_options,
 			break;
 		}
 
-		optstring[str_pos++] = (char)long_options[i].val;
-		if (long_options[i].has_arg) {
-			optstring[str_pos++] = ':';
+		if (long_options[i].val != '\0') {
+			optstring[str_pos++] = (char) long_options[i].val;
+			if (long_options[i].has_arg) {
+				optstring[str_pos++] = ':';
+			}
 		}
 	}
 
 end:
 	return optstring;
 }
+
+/*
+ * Try to remove a hierarchy of empty directories, recursively. Don't unlink
+ * any file. Try to rmdir any empty directory within the hierarchy.
+ */
+LTTNG_HIDDEN
+int utils_recursive_rmdir(const char *path)
+{
+	DIR *dir;
+	int dir_fd, ret = 0, closeret, is_empty = 1;
+	struct dirent *entry;
+
+	/* Open directory */
+	dir = opendir(path);
+	if (!dir) {
+		PERROR("Cannot open '%s' path", path);
+		return -1;
+	}
+	dir_fd = dirfd(dir);
+	if (dir_fd < 0) {
+		PERROR("dirfd");
+		return -1;
+	}
+
+	while ((entry = readdir(dir))) {
+		if (!strcmp(entry->d_name, ".")
+				|| !strcmp(entry->d_name, ".."))
+			continue;
+		switch (entry->d_type) {
+		case DT_DIR:
+		{
+			char subpath[PATH_MAX];
+
+			strncpy(subpath, path, PATH_MAX);
+			subpath[PATH_MAX - 1] = '\0';
+			strncat(subpath, "/",
+				PATH_MAX - strlen(subpath) - 1);
+			strncat(subpath, entry->d_name,
+				PATH_MAX - strlen(subpath) - 1);
+			if (utils_recursive_rmdir(subpath)) {
+				is_empty = 0;
+			}
+			break;
+		}
+		case DT_REG:
+			is_empty = 0;
+			break;
+		default:
+			ret = -EINVAL;
+			goto end;
+		}
+	}
+end:
+	closeret = closedir(dir);
+	if (closeret) {
+		PERROR("closedir");
+	}
+	if (is_empty) {
+		DBG3("Attempting rmdir %s", path);
+		ret = rmdir(path);
+	}
+	return ret;
+}