Separate cpio logic from MagiskBoot

2025-09-06 06:36:58 +00:00 · 2017-12-01 17:17:24 +08:00
parent a30777bd9f
commit a5e4f3cc6b
6 changed files with 251 additions and 228 deletions
@@ -0,0 +1,146 @@
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include "magiskboot.h"
+#include "cpio.h"
+
+int check_verity_pattern(const char *s) {
+	int pos = 0;
+	if (s[0] == ',') ++pos;
+	if (strncmp(s + pos, "verify", 6) == 0)
+		pos += 6;
+	else if (strncmp(s + pos, "avb", 3) == 0)
+		pos += 3;
+	else
+		return -1;
+
+	if (s[pos] == '=') {
+		while (s[pos] != '\0' && s[pos] != ' ' && s[pos] != '\n' && s[pos] != ',') ++pos;
+	}
+	return pos;
+}
+
+int check_encryption_pattern(const char *s) {
+	const char *encrypt_list[] = { "forceencrypt", "forcefdeorfbe", NULL };
+	for (int i = 0 ; encrypt_list[i]; ++i) {
+		int len = strlen(encrypt_list[i]);
+		if (strncmp(s, encrypt_list[i], len) == 0)
+			return len;
+	}
+	return -1;
+}
+
+void cpio_patch(struct vector *v, int keepverity, int keepforceencrypt) {
+	cpio_entry *f;
+	int skip, write;
+	vec_for_each(v, f) {
+		if (!keepverity) {
+			if (strstr(f->filename, "fstab") != NULL && S_ISREG(f->mode)) {
+				write = 0;
+				for (int read = 0; read < f->filesize; ++write, ++read) {
+					if ((skip = check_verity_pattern(f->data + read)) > 0) {
+						fprintf(stderr, "Remove pattern [%.*s] in [%s]\n", skip, f->data + read, f->filename);
+						read += skip;
+					}
+					f->data[write] = f->data[read];
+				}
+				f->filesize = write;
+			} else if (strcmp(f->filename, "verity_key") == 0) {
+				fprintf(stderr, "Remove [verity_key]\n");
+				f->remove = 1;
+			}
+		}
+		if (!keepforceencrypt) {
+			if (strstr(f->filename, "fstab") != NULL && S_ISREG(f->mode)) {
+				write = 0;
+				for (int read = 0; read < f->filesize; ++write, ++read) {
+					if ((skip = check_encryption_pattern(f->data + read)) > 0) {
+						// assert(skip > 11)!
+						fprintf(stderr, "Replace pattern [%.*s] with [encryptable] in [%s]\n", skip, f->data + read, f->filename);
+						memcpy(f->data + write, "encryptable", 11);
+						write += 11;
+						read += skip;
+					}
+					f->data[write] = f->data[read];
+				}
+				f->filesize = write;
+			}
+		}
+	}
+}
+
+int cpio_commands(const char *command, int argc, char *argv[]) {
+	int recursive = 0, ret = 0;
+	command_t cmd;
+	char *incpio = argv[0];
+	++argv;
+	--argc;
+	if (strcmp(command, "test") == 0) {
+		cmd = TEST;
+	} else if (strcmp(command, "restore") == 0) {
+		cmd = RESTORE;
+	} else if (strcmp(command, "stocksha1") == 0) {
+		cmd = STOCKSHA1;
+	} else if (argc >= 1 && strcmp(command, "backup") == 0) {
+		cmd = BACKUP;
+	} else if (argc > 0 && strcmp(command, "rm") == 0) {
+		cmd = RM;
+		if (argc == 2 && strcmp(argv[0], "-r") == 0) {
+			recursive = 1;
+			++argv;
+			--argc;
+		}
+	} else if (argc == 2 && strcmp(command, "mv") == 0) {
+		cmd = MV;
+	} else if (argc == 2 && strcmp(command, "patch") == 0) {
+		cmd = PATCH;
+	} else if (argc == 2 && strcmp(command, "extract") == 0) {
+		cmd = EXTRACT;
+	} else if (argc == 2 && strcmp(command, "mkdir") == 0) {
+		cmd = MKDIR;
+	} else if (argc == 3 && strcmp(command, "add") == 0) {
+		cmd = ADD;
+	} else {
+		cmd = NONE;
+	}
+	struct vector v;
+	vec_init(&v);
+	parse_cpio(incpio, &v);
+	switch(cmd) {
+	case TEST:
+		cpio_test(&v);
+		break;
+	case RESTORE:
+		ret = cpio_restore(&v);
+		break;
+	case STOCKSHA1:
+		cpio_stocksha1(&v);
+		return 0;
+	case BACKUP:
+		cpio_backup(argv[0], argc > 1 ? argv[1] : NULL, &v);
+	case RM:
+		cpio_rm(recursive, argv[0], &v);
+		break;
+	case PATCH:
+		cpio_patch(&v, strcmp(argv[0], "true") == 0, strcmp(argv[1], "true") == 0);
+		break;
+	case EXTRACT:
+		cpio_extract(argv[0], argv[1], &v);
+		break;
+	case MKDIR:
+		cpio_mkdir(strtoul(argv[0], NULL, 8), argv[1], &v);
+		break;
+	case ADD:
+		cpio_add(strtoul(argv[0], NULL, 8), argv[1], argv[2], &v);
+		break;
+	case MV:
+		cpio_mv(&v, argv[0], argv[1]);
+		break;
+	case NONE:
+		return 1;
+	}
+	dump_cpio(incpio, &v);
+	cpio_vec_destroy(&v);
+	exit(ret);
+}