--- trunk/grubby/grubby.c	2020/07/07 11:09:37	3136
+++ trunk/grubby/grubby.c	2020/07/07 11:24:19	3150
@@ -68,6 +68,8 @@
 
 char *saved_command_line = NULL;
 
+const char *mounts = "/proc/mounts";
+
 /* comments get lumped in with indention */
 struct lineElement {
 	char *item;
@@ -480,20 +482,28 @@
 	snprintf(result, resultMaxSize, "%s", ++current);
 
 	i++;
+	int result_len = 0;
 	for (; i < line->numElements; ++i) {
 		current = line->elements[i].item;
 		current_len = strlen(current);
 		current_indent = line->elements[i].indent;
 		current_indent_len = strlen(current_indent);
 
-		strncat(result, current_indent, current_indent_len);
+		memcpy(result + result_len, current_indent, current_indent_len);
+		result_len += current_indent_len;
+
 		if (current[current_len - 1] != quote_char) {
-			strncat(result, current, current_len);
+			memcpy(result + result_len, current_indent,
+			       current_indent_len);
+			result_len += current_len;
 		} else {
-			strncat(result, current, current_len - 1);
+			memcpy(result + result_len, current_indent,
+			       current_indent_len);
+			result_len += (current_len - 1);
 			break;
 		}
 	}
+	result[result_len] = '\0';
 	return result;
 }
 
@@ -701,7 +711,7 @@
 		     struct configFileInfo *cfi);
 static int getNextLine(char **bufPtr, struct singleLine *line,
 		       struct configFileInfo *cfi);
-static char *getRootSpecifier(char *str);
+static size_t getRootSpecifier(const char *str);
 static void requote(struct singleLine *line, struct configFileInfo *cfi);
 static void insertElement(struct singleLine *line,
 			  const char *item, int insertHere,
@@ -1438,6 +1448,7 @@
 			extras = malloc(len + 1);
 			*extras = '\0';
 
+			int buf_len = 0;
 			/* get title. */
 			for (int i = 0; i < line->numElements; i++) {
 				if (!strcmp
@@ -1454,13 +1465,18 @@
 
 				len = strlen(title);
 				if (title[len - 1] == quote_char) {
-					strncat(buf, title, len - 1);
+					memcpy(buf + buf_len, title, len - 1);
+					buf_len += (len - 1);
 					break;
 				} else {
-					strcat(buf, title);
-					strcat(buf, line->elements[i].indent);
+					memcpy(buf + buf_len, title, len);
+					buf_len += len;
+					len = strlen(line->elements[i].indent);
+					memcpy(buf + buf_len, line->elements[i].indent, len);
+					buf_len += len;
 				}
 			}
+			buf[buf_len] = '\0';
 
 			/* get extras */
 			int count = 0;
@@ -2118,6 +2134,129 @@
 	return s[slen] == c;
 }
 
+typedef struct {
+	const char *start;
+	size_t      chars;
+} field;
+
+static int iscomma(int c)
+{
+	return c == ',';
+}
+
+static int isequal(int c)
+{
+	return c == '=';
+}
+
+static field findField(const field *in, typeof(isspace) *isdelim, field *out)
+{
+	field nxt = {};
+	size_t off = 0;
+
+	while (off < in->chars && isdelim(in->start[off]))
+		off++;
+
+	if (off == in->chars)
+		return nxt;
+
+	out->start = &in->start[off];
+	out->chars = 0;
+
+	while (off + out->chars < in->chars && !isdelim(out->start[out->chars]))
+		out->chars++;
+
+	nxt.start = out->start + out->chars;
+	nxt.chars = in->chars - off - out->chars;
+	return nxt;
+}
+
+static int fieldEquals(const field *in, const char *str)
+{
+	return in->chars == strlen(str) &&
+		strncmp(in->start, str, in->chars) == 0;
+}
+
+/* Parse /proc/mounts to determine the subvolume prefix. */
+static size_t subvolPrefix(const char *str)
+{
+	FILE *file = NULL;
+	char *line = NULL;
+	size_t prfx = 0;
+	size_t size = 0;
+
+	file = fopen(mounts, "r");
+	if (!file)
+		return 0;
+
+	for (ssize_t s; (s = getline(&line, &size, file)) >= 0; ) {
+		field nxt = { line, s };
+		field dev = {};
+		field path = {};
+		field type = {};
+		field opts = {};
+		field opt = {};
+
+		nxt = findField(&nxt, isspace, &dev);
+		if (!nxt.start)
+			continue;
+
+		nxt = findField(&nxt, isspace, &path);
+		if (!nxt.start)
+			continue;
+
+		nxt = findField(&nxt, isspace, &type);
+		if (!nxt.start)
+			continue;
+
+		nxt = findField(&nxt, isspace, &opts);
+		if (!nxt.start)
+			continue;
+
+		if (!fieldEquals(&type, "btrfs"))
+			continue;
+
+		/* We have found a btrfs mount point. */
+
+		nxt = opts;
+		while ((nxt = findField(&nxt, iscomma, &opt)).start) {
+			field key = {};
+			field val = {};
+
+			opt = findField(&opt, isequal, &key);
+			if (!opt.start)
+				continue;
+
+			opt = findField(&opt, isequal, &val);
+			if (!opt.start)
+				continue;
+
+			if (!fieldEquals(&key, "subvol"))
+				continue;
+
+			/* We have found a btrfs subvolume mount point. */
+
+			if (strncmp(val.start, str, val.chars))
+				continue;
+
+			if (val.start[val.chars - 1] != '/' &&
+				str[val.chars] != '/')
+				continue;
+
+			/* The subvolume mount point matches our input. */
+
+			if (prfx < val.chars)
+				prfx = val.chars;
+		}
+	}
+
+	dbgPrintf("%s(): str: '%s', prfx: '%s'\n", __FUNCTION__, str, prfx);
+
+	fclose(file);
+	free(line);
+	return prfx;
+}
+
 int suitableImage(struct singleEntry *entry, const char *bootPrefix,
 		  int skipRemoved, int flags)
 {
@@ -2125,7 +2264,7 @@
 	char *fullName;
 	int i;
 	char *dev;
-	char *rootspec;
+	size_t rs;
 	char *rootdev;
 
 	if (skipRemoved && entry->skip) {
@@ -2153,12 +2292,11 @@
 
 	fullName = alloca(strlen(bootPrefix) +
 			  strlen(line->elements[1].item) + 1);
-	rootspec = getRootSpecifier(line->elements[1].item);
-	int rootspec_offset = rootspec ? strlen(rootspec) : 0;
+	rs = getRootSpecifier(line->elements[1].item);
 	int hasslash = endswith(bootPrefix, '/') ||
-	    beginswith(line->elements[1].item + rootspec_offset, '/');
+	    beginswith(line->elements[1].item + rs, '/');
 	sprintf(fullName, "%s%s%s", bootPrefix, hasslash ? "" : "/",
-		line->elements[1].item + rootspec_offset);
+		line->elements[1].item + rs);
 	if (access(fullName, R_OK)) {
 		notSuitablePrintf(entry, 0, "access to %s failed\n", fullName);
 		return 0;
@@ -2250,7 +2388,6 @@
 	struct singleLine *line;
 	int i;
 	char *chptr;
-	char *rootspec = NULL;
 	enum lineType_e checkType = LT_KERNEL;
 
 	if (isdigit(*kernel)) {
@@ -2355,14 +2492,10 @@
 
 				if (line && line->type != LT_MENUENTRY &&
 				    line->numElements >= 2) {
-					rootspec =
-					    getRootSpecifier(line->elements[1].
-							     item);
-					if (!strcmp
-					    (line->elements[1].item +
-					     ((rootspec !=
-					       NULL) ? strlen(rootspec) : 0),
-					     kernel + strlen(prefix)))
+					if (!strcmp(line->elements[1].item +
+						getRootSpecifier(
+							line->elements[1].item),
+						kernel + strlen(prefix)))
 						break;
 				}
 				if (line->type == LT_MENUENTRY &&
@@ -3271,12 +3404,22 @@
 		    type & (LT_HYPER | LT_KERNEL | LT_MBMODULE | LT_INITRD |
 			    LT_KERNEL_EFI | LT_INITRD_EFI | LT_KERNEL_16 |
 			    LT_INITRD_16)) {
-			char *rootspec =
-			    getRootSpecifier(tmplLine->elements[1].item);
-			if (rootspec != NULL) {
+			const char *prfx = tmplLine->elements[1].item;
+			size_t rs = getRootSpecifier(prfx);
+			if (isinitrd(tmplLine->type)) {
+				for (struct singleLine *l = entry->lines;
+				     rs == 0 && l; l = l->next) {
+					if (iskernel(l->type)) {
+						prfx = l->elements[1].item;
+						rs = getRootSpecifier(prfx);
+						break;
+					}
+				}
+			}
+			if (rs > 0) {
 				free(newLine->elements[1].item);
-				newLine->elements[1].item =
-				    sdupprintf("%s%s", rootspec, val);
+				newLine->elements[1].item = sdupprintf(
+					"%.*s%s", (int) rs, prfx, val);
 			}
 		}
 	}
@@ -3621,9 +3764,9 @@
 
 	if (!chptra && !chptrb)
 		return 0;
-	else if (!chptra)
+	else if (!chptra && chptrb)
 		return *chptrb - 0;
-	else if (!chptrb)
+	else if (!chptrb && chptra)
 		return 0 - *chptra;
 	else
 		return strcmp(chptra, chptrb);
@@ -4328,17 +4471,19 @@
 	return 1;
 }
 
-static char *getRootSpecifier(char *str)
+static size_t getRootSpecifier(const char *str)
 {
-	char *idx, *rootspec = NULL;
+	size_t rs = 0;
 
 	if (*str == '(') {
-		idx = rootspec = strdup(str);
-		while (*idx && (*idx != ')') && (!isspace(*idx)))
-			idx++;
-		*(++idx) = '\0';
+		for (; str[rs] != ')' && !isspace(str[rs]); rs++) {
+			if (!str[rs])
+				return rs;
+		}
+		rs++;
 	}
-	return rootspec;
+
+	return rs + subvolPrefix(str + rs);
 }
 
 static char *getInitrdVal(struct grubConfig *config,
@@ -4970,6 +5115,9 @@
 		{"mbargs", 0, POPT_ARG_STRING, &newMBKernelArgs, 0,
 		 _("default arguments for the new multiboot kernel or "
 		   "new arguments for multiboot kernel being updated"), NULL},
+		{"mounts", 0, POPT_ARG_STRING, &mounts, 0,
+		 _("path to fake /proc/mounts file (for testing only)"),
+		 _("mounts")},
 		{"bad-image-okay", 0, 0, &badImageOkay, 0,
 		 _
 		 ("don't sanity check images in boot entries (for testing only)"),
@@ -5078,10 +5226,18 @@
 		exit(1);
 	}
 	saved_command_line[0] = '\0';
+	int cmdline_len = 0, arg_len;
 	for (int j = 1; j < argc; j++) {
-		strcat(saved_command_line, argv[j]);
-		strncat(saved_command_line, j == argc - 1 ? "" : " ", 1);
+		arg_len = strlen(argv[j]);
+		memcpy(saved_command_line + cmdline_len, argv[j], arg_len);
+		cmdline_len += arg_len;
+		if (j != argc - 1) {
+			memcpy(saved_command_line + cmdline_len, " ", 1);
+			cmdline_len++;
+		}
+
 	}
+	saved_command_line[cmdline_len] = '\0';
 
 	optCon = poptGetContext("grubby", argc, argv, options, 0);
 	poptReadDefaultConfig(optCon, 1);
@@ -5154,22 +5310,27 @@
 	if (!cfi) {
 		if (grub2FindConfig(&grub2ConfigType)) {
 			cfi = &grub2ConfigType;
+			configureGrub2 = 1;
 			if (envPath)
 				cfi->envFile = envPath;
-		} else
+		} else {
 #ifdef __ia64__
 			cfi = &eliloConfigType;
-#elif __powerpc__
+			configureLilo = 1;
+#elif defined(__powerpc__)
 			cfi = &yabootConfigType;
-#elif __sparc__
+			configureYaboot = 1;
+#elif defined(__sparc__)
 			cfi = &siloConfigType;
-#elif __s390__
+			configureSilo = 1;
+#elif defined(__s390__) || defined(__s390x__)
 			cfi = &ziplConfigType;
-#elif __s390x__
-			cfi = &ziplConfigtype;
+			configureZipl = 1;
 #else
 			cfi = &grubConfigType;
+			configureGrub = 1;
 #endif
+		}
 	}
 
 	if (!grubConfig) {
@@ -5363,7 +5524,7 @@
 	if (displayDefault) {
 		struct singleLine *line;
 		struct singleEntry *entry;
-		char *rootspec;
+		size_t rs;
 
 		if (config->defaultImage == NO_DEFAULT_ENTRY)
 			return 0;
@@ -5382,9 +5543,8 @@
 		if (!line)
 			return 0;
 
-		rootspec = getRootSpecifier(line->elements[1].item);
-		printf("%s%s\n", bootPrefix, line->elements[1].item +
-		       ((rootspec != NULL) ? strlen(rootspec) : 0));
+		rs = getRootSpecifier(line->elements[1].item);
+		printf("%s%s\n", bootPrefix, line->elements[1].item + rs);
 
 		return 0;