saleae-logic: 1.1.15 -> 1.2.9

Changelog:
http://support.saleae.com/hc/en-us/articles/210245593-Saleae-Logic-Beta-Software-Changelog

(Yes, the changelog title contains the word 'beta', but as of version
1.2.9 the beta branding is removed from the software as the beta branch
was merged to master.)

This software update is required for newer logic analysers (e.g. Logic
Pro 8). (The original Logic is still supported, although it's difficult
to find info about it on their website.)

v1.2.9 grew new dependencies: libxcb, zlib, pciutils, xkeyboardconfig.

The LD_PRELOAD library hack, used to divert writes from
$out/Settings/settings.xml to $HOME/.saleae-logic-settings.xml, has been
updated. The new software writes more paths
($out/{Settings,Errors,Databases,Calibration}) and uses a few extra
library calls to access those paths
(open,openat,stat,access,unlink,...). So instead of single file
redirect, the library now redirects accesses to all those directories,
mirrored in $HOME/.saleae-logic/. (Existing
$HOME/.saleae-logic-settings.xml files will be automatically migrated to
$HOME/.saleae-logic/Settings/settings.xml.)

1 files changed, 248 insertions, 21 deletions

diff --git a/pkgs/development/tools/misc/saleae-logic/preload.c b/pkgs/development/tools/misc/saleae-logic/preload.c
index 6b3632db97b..b4451e4d99f 100644
--- a/pkgs/development/tools/misc/saleae-logic/preload.c
+++ b/pkgs/development/tools/misc/saleae-logic/preload.c
@@ -2,17 +2,20 @@
  * LD_PRELOAD trick to make Saleae Logic work from a read-only installation
  * directory.
  *
- * Saleae Logic tries to write to the ./Settings/settings.xml file, relative to
- * its installation directory. Because the nix store is read-only, we have to
- * redirect access to this file somewhere else. Here's the map:
+ * Saleae Logic tries to write to a few directories inside its installation
+ * directory. Because the Nix store is read-only, we have to redirect access to
+ * this file somewhere else. Here's the map:
  *
- *   $out/Settings/settings.xml => $HOME/.saleae-logic-settings.xml
+ *   $out/Settings/    => $HOME/.saleae-logic/Settings/
+ *   $out/Databases/   => $HOME/.saleae-logic/Databases/
+ *   $out/Errors/      => $HOME/.saleae-logic/Errors/
+ *   $out/Calibration/ => $HOME/.saleae-logic/Calibration/
  *
  * This also makes the software multi-user aware :-)
  *
- * NOTE: The next Logic version is supposed to have command line parameters for
- * configuring where the Settings/ directory is located, but until then we have
- * to use this.
+ * NOTE: AFAIK (Bjørn Forsman), Logic version 1.2+ was supposed to have a
+ * command line parameter for redirecting these write operations, but
+ * apparently that feature got postponed.
  *
  * Usage:
  *   gcc -shared -fPIC -DOUT="$out" preload.c -o preload.so -ldl
@@ -33,30 +36,65 @@
 #include <limits.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <errno.h>
 
 #ifndef OUT
 #error Missing OUT define - path to the installation directory.
 #endif
 
+/*
+ * TODO: How to properly wrap "open", which is declared as a variadic function
+ * in glibc? The man page lists these signatures:
+ *
+ *   int open(const char *pathname, int flags);
+ *   int open(const char *pathname, int flags, mode_t mode);
+ *
+ * But using either signature in this code cause a compile error, because
+ * glibc has declared the function as "int open(const char *, int, ...)".
+ * Same thing with "openat".
+ *
+ * For now we discard the variadic args. It seems to work.
+ *
+ * Relevant:
+ * http://stackoverflow.com/questions/28462523/how-to-wrap-ioctlint-d-unsigned-long-request-using-ld-preload
+ */
 typedef FILE *(*fopen_func_t)(const char *path, const char *mode);
 typedef FILE *(*fopen64_func_t)(const char *path, const char *mode);
+typedef int (*open_func_t)(const char *pathname, int flags, ...);
+typedef int (*open64_func_t)(const char *pathname, int flags, ...);
+typedef int (*openat_func_t)(int dirfd, const char *pathname, int flags, ...);
+typedef int (*openat64_func_t)(int dirfd, const char *pathname, int flags, ...);
+typedef int (*xstat_func_t)(int vers, const char *pathname, struct stat *buf);
+typedef int (*xstat64_func_t)(int vers, const char *pathname, struct stat64 *buf);
+typedef int (*access_func_t)(const char *pathname, int mode);
+typedef int (*faccessat_func_t)(int dirfd, const char *pathname, int mode, int flags);
+typedef int (*unlink_func_t)(const char *pathname);
 
 /*
- * Redirect $out/Settings/settings.xml => $HOME/.saleae-logic-settings.xml. No
- * other paths are changed. Path is truncated if bigger than PATH_MAX.
+ * Redirect $out/{Settings,Databases,Errors,Calibration}/ => $HOME/.saleae-logic/.
+ * Path is truncated if bigger than PATH_MAX.
  *
  * @param pathname Original file path.
  * @param buffer Pointer to a buffer of size PATH_MAX bytes that this function
  * will write the new redirected path to (if needed).
  *
  * @return Pointer to the resulting path. It will either be equal to the
- * pathname or buffer argument.
+ * pathname (no redirect) or buffer argument (was redirected).
  */
 static const char *redirect(const char *pathname, char *buffer)
 {
 	const char *homepath;
 	const char *new_path;
 	static char have_warned;
+	const char *remainder;
+	static char have_initialized;
+	static size_t out_strlen;
+	static size_t settings_strlen;
+	static size_t databases_strlen;
+	static size_t errors_strlen;
+	static size_t calibration_strlen;
+	int ret;
+	int i;
 
 	homepath = getenv("HOME");
 	if (!homepath) {
@@ -67,9 +105,59 @@ static const char *redirect(const char *pathname, char *buffer)
 		}
 	}
 
+	if (!have_initialized) {
+		/*
+		 * The directories that Saleae Logic expects to find.
+		 * The first element is intentionally empty (create base dir).
+		 */
+		char *dirs[] = {"", "/Settings", "/Databases", "/Errors", "/Calibration"};
+		char old_settings_path[PATH_MAX];
+		access_func_t orig_access;
+
+		out_strlen = strlen(OUT);
+		settings_strlen = out_strlen + strlen("/Settings");
+		databases_strlen = out_strlen + strlen("/Databases");
+		errors_strlen = out_strlen + strlen("/Errors");
+		calibration_strlen = out_strlen + strlen("/Calibration");
+		for (i = 0; i < sizeof dirs / sizeof dirs[0]; i++) {
+			snprintf(buffer, PATH_MAX, "%s/.saleae-logic%s", homepath, dirs[i]);
+			buffer[PATH_MAX-1] = '\0';
+			ret = mkdir(buffer, 0755);
+			if (0 != ret && errno != EEXIST) {
+				fprintf(stderr, "ERROR: Failed to create directory \"%s\": %s\n",
+						buffer, strerror(errno));
+				return NULL;
+			}
+		}
+
+		/*
+		 * Automatic migration of the settings file:
+		 * ~/.saleae-logic-settings.xml => ~/.saleae-logic/Settings/settings.xml
+		 */
+		snprintf(old_settings_path, PATH_MAX, "%s/.saleae-logic-settings.xml", homepath);
+		old_settings_path[PATH_MAX-1] = '\0';
+		orig_access = (access_func_t)dlsym(RTLD_NEXT, "access");
+		if (orig_access(old_settings_path, F_OK) == 0) {
+			snprintf(buffer, PATH_MAX, "%s/.saleae-logic/Settings/settings.xml", homepath);
+			buffer[PATH_MAX-1] = '\0';
+			ret = rename(old_settings_path, buffer);
+			if (ret != 0) {
+				fprintf(stderr, "WARN: Failed to move %s to %s",
+						old_settings_path, buffer);
+			}
+		}
+
+		have_initialized = 1;
+	}
+
 	new_path = pathname;
-	if (strcmp(OUT "/Settings/settings.xml", pathname) == 0) {
-		snprintf(buffer, PATH_MAX, "%s/.saleae-logic-settings.xml", homepath);
+	remainder = pathname + out_strlen;
+
+	if ((strncmp(OUT "/Settings", pathname, settings_strlen) == 0) ||
+	    (strncmp(OUT "/Databases", pathname, databases_strlen) == 0) ||
+	    (strncmp(OUT "/Errors", pathname, errors_strlen) == 0) ||
+	    (strncmp(OUT "/Calibration", pathname, calibration_strlen) == 0)) {
+		snprintf(buffer, PATH_MAX, "%s/.saleae-logic%s", homepath, remainder);
 		buffer[PATH_MAX-1] = '\0';
 		new_path = buffer;
 	}
@@ -79,36 +167,175 @@ static const char *redirect(const char *pathname, char *buffer)
 
 FILE *fopen(const char *pathname, const char *mode)
 {
-	FILE *fp;
 	const char *path;
 	char buffer[PATH_MAX];
 	fopen_func_t orig_fopen;
 
 	orig_fopen = (fopen_func_t)dlsym(RTLD_NEXT, "fopen");
 	path = redirect(pathname, buffer);
-	fp = orig_fopen(path, mode);
-
 	if (path != pathname && getenv("PRELOAD_DEBUG")) {
-		fprintf(stderr, "preload_debug: fopen(\"%s\", \"%s\") => \"%s\": fp=%p\n", pathname, mode, path, fp);
+		fprintf(stderr, "preload_debug: fopen(\"%s\", \"%s\") => \"%s\"\n", pathname, mode, path);
 	}
 
-	return fp;
+	return orig_fopen(path, mode);
 }
 
 FILE *fopen64(const char *pathname, const char *mode)
 {
-	FILE *fp;
 	const char *path;
 	char buffer[PATH_MAX];
 	fopen64_func_t orig_fopen64;
 
 	orig_fopen64 = (fopen64_func_t)dlsym(RTLD_NEXT, "fopen64");
 	path = redirect(pathname, buffer);
-	fp = orig_fopen64(path, mode);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: fopen64(\"%s\", \"%s\") => \"%s\"\n", pathname, mode, path);
+	}
+
+	return orig_fopen64(path, mode);
+}
+
+int open(const char *pathname, int flags, ...)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	open_func_t orig_open;
+
+	orig_open = (open_func_t)dlsym(RTLD_NEXT, "open");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: open(\"%s\", ...) => \"%s\"\n", pathname, path);
+	}
+
+	return orig_open(path, flags);
+}
+
+int open64(const char *pathname, int flags, ...)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	open64_func_t orig_open64;
+
+	orig_open64 = (open64_func_t)dlsym(RTLD_NEXT, "open64");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: open64(\"%s\", ...) => \"%s\"\n", pathname, path);
+	}
 
+	return orig_open64(path, flags);
+}
+
+int openat(int dirfd, const char *pathname, int flags, ...)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	openat_func_t orig_openat;
+
+	orig_openat = (openat_func_t)dlsym(RTLD_NEXT, "openat");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: openat(%d, \"%s\", %#x) => \"%s\"\n", dirfd, pathname, flags, path);
+	}
+
+	return orig_openat(dirfd, path, flags);
+}
+
+int openat64(int dirfd, const char *pathname, int flags, ...)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	openat64_func_t orig_openat64;
+
+	orig_openat64 = (openat64_func_t)dlsym(RTLD_NEXT, "openat64");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: openat64(%d, \"%s\", %#x) => \"%s\"\n", dirfd, pathname, flags, path);
+	}
+
+	return orig_openat64(dirfd, path, flags);
+}
+
+/*
+ * Notes about "stat".
+ *
+ * The stat function is special, at least in glibc, in that it cannot be
+ * directly overridden by LD_PRELOAD, due to it being inline wrapper around
+ * __xstat. The __xstat functions take one extra parameter, a version number,
+ * to indicate what "struct stat" should look like. This trick allows changing
+ * the contents of mode_t without changing the shared library major number. See
+ * sys/stat.h header for more info.
+ */
+int __xstat(int vers, const char *pathname, struct stat *buf)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	xstat_func_t orig_xstat;
+
+	orig_xstat = (xstat_func_t)dlsym(RTLD_NEXT, "__xstat");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: (__x)stat(\"%s\", ...) => \"%s\"\n", pathname, path);
+	}
+
+	return orig_xstat(vers, path, buf);
+}
+
+int __xstat64(int vers, const char *pathname, struct stat64 *buf)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	xstat64_func_t orig_xstat64;
+
+	orig_xstat64 = (xstat64_func_t)dlsym(RTLD_NEXT, "__xstat64");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: (__x)stat64(\"%s\", ...) => \"%s\"\n", pathname, path);
+	}
+
+	return orig_xstat64(vers, path, buf);
+}
+
+int access(const char *pathname, int mode)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	access_func_t orig_access;
+
+	orig_access = (access_func_t)dlsym(RTLD_NEXT, "access");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: access(\"%s\", ...) => \"%s\"\n", pathname, path);
+	}
+
+	return orig_access(path, mode);
+}
+
+int faccessat(int dirfd, const char *pathname, int mode, int flags)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	faccessat_func_t orig_faccessat;
+
+	orig_faccessat = (faccessat_func_t)dlsym(RTLD_NEXT, "faccessat");
+	path = redirect(pathname, buffer);
+	if (path != pathname && getenv("PRELOAD_DEBUG")) {
+		fprintf(stderr, "preload_debug: faccessat(\"%s\", ...) => \"%s\"\n", pathname, path);
+	}
+
+	return orig_faccessat(dirfd, path, mode, flags);
+}
+
+int unlink(const char *pathname)
+{
+	const char *path;
+	char buffer[PATH_MAX];
+	unlink_func_t orig_unlink;
+
+	orig_unlink = (unlink_func_t)dlsym(RTLD_NEXT, "unlink");
+	path = redirect(pathname, buffer);
 	if (path != pathname && getenv("PRELOAD_DEBUG")) {
-		fprintf(stderr, "preload_debug: fopen64(\"%s\", \"%s\") => \"%s\": fp=%p\n", pathname, mode, path, fp);
+		fprintf(stderr, "preload_debug: unlink(\"%s\") => \"%s\"\n", pathname, path);
 	}
 
-	return fp;
+	return orig_unlink(path);
 }