MarcoBuster/Magisk
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Better cmdline parsing

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This commit is contained in:
topjohnwu 2019-02-09 05:23:56 -05:00
parent ed25e1bbd6
commit 1f5267204b
1 changed files with 64 additions and 38 deletions
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102
native/jni/core/init.cpp
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@ -33,6 +33,8 @@
#include <sys/mman.h>
#include <sys/sendfile.h>
#include <sys/sysmacros.h>
#include <functional>
#include <string_view>
#include <xz.h>
@ -70,38 +72,62 @@ struct device {
char path[64];
};
static void parse_cmdline(struct cmdline *cmd) {
// cleanup
memset(cmd, 0, sizeof(*cmd));
static void parse_cmdline(const std::function<void (std::string_view, const char *)> &fn) {
char cmdline[4096];
int fd = open("/proc/cmdline", O_RDONLY | O_CLOEXEC);
cmdline[read(fd, cmdline, sizeof(cmdline))] = '\0';
close(fd);
bool skip_initramfs = false, kirin = false;
int enter_recovery = 0;
for (char *tok = strtok(cmdline, " "); tok; tok = strtok(nullptr, " ")) {
if (strncmp(tok, "androidboot.slot_suffix", 23) == 0) {
sscanf(tok, "androidboot.slot_suffix=%s", cmd->slot);
} else if (strncmp(tok, "androidboot.slot", 16) == 0) {
cmd->slot[0] = '_';
sscanf(tok, "androidboot.slot=%c", cmd->slot + 1);
} else if (strcmp(tok, "skip_initramfs") == 0) {
skip_initramfs = true;
} else if (strncmp(tok, "androidboot.android_dt_dir", 26) == 0) {
sscanf(tok, "androidboot.android_dt_dir=%s", cmd->dt_dir);
} else if (strncmp(tok, "enter_recovery", 14) == 0) {
sscanf(tok, "enter_recovery=%d", &enter_recovery);
} else if (strncmp(tok, "androidboot.hardware", 20) == 0) {
kirin = strstr(tok, "kirin") || strstr(tok, "hi3660");
char *tok, *eql, *tmp, *saveptr;
saveptr = cmdline;
while ((tok = strtok_r(nullptr, " \n", &saveptr)) != nullptr) {
eql = strchr(tok, '=');
if (eql) {
*eql = '\0';
if (eql[1] == '"') {
tmp = strchr(saveptr, '"');
if (tmp != nullptr) {
*tmp = '\0';
saveptr[-1] = ' ';
saveptr = tmp + 1;
eql++;
}
}
fn(tok, eql + 1);
} else {
fn(tok, "");
}
}
}
static void parse_cmdline(struct cmdline *cmd) {
char cmdline[4096];
int fd = open("/proc/cmdline", O_RDONLY | O_CLOEXEC);
cmdline[read(fd, cmdline, sizeof(cmdline))] = '\0';
close(fd);
bool skip_initramfs = false, kirin = false, enter_recovery = false;
parse_cmdline([&](auto key, auto value) -> void {
if (key == "androidboot.slot_suffix") {
strcpy(cmd->slot, value);
} else if (key == "androidboot.slot") {
cmd->slot[0] = '_';
strcpy(cmd->slot + 1, value);
} else if (key == "skip_initramfs") {
skip_initramfs = true;
} else if (key == "androidboot.android_dt_dir") {
strcpy(cmd->dt_dir, value);
} else if (key == "entry_recovery") {
enter_recovery = value[0] == '1';
} else if (key == "androidboot.hardware") {
kirin = strstr(value, "kirin") || strstr(value, "hi3660");
}
});
if (kirin && enter_recovery) {
// Inform that we are actually booting as recovery
FILE *f = fopen("/.backup/.magisk", "a");
FILE *f = fopen("/.backup/.magisk", "ae");
fprintf(f, "RECOVERYMODE=true\n");
fclose(f);
cmd->early_boot = true;
@ -139,7 +165,7 @@ static bool setup_block(struct device *dev, const char *partname) {
struct dirent *entry;
DIR *dir = opendir("/sys/dev/block");
if (dir == nullptr)
return 1;
return false;
bool found = false;
while ((entry = readdir(dir))) {
if (strcmp(entry->d_name, ".") == 0 || strcmp(entry->d_name, "..") == 0)
@ -171,16 +197,15 @@ static bool read_fstab_dt(const struct cmdline *cmd, const char *mnt_point, char
// Don't early mount if the mount point is symlink
if (S_ISLNK(st.st_mode))
return false;
int fd;
sprintf(buf, "%s/fstab/%s/dev", cmd->dt_dir, mnt_point);
if (access(buf, F_OK) == 0) {
int fd = open(buf, O_RDONLY | O_CLOEXEC);
if ((fd = xopen(buf, O_RDONLY | O_CLOEXEC)) >= 0) {
read(fd, buf, sizeof(buf));
close(fd);
char *name = strrchr(buf, '/') + 1;
sprintf(partname, "%s%s", name, strend(name, cmd->slot) ? cmd->slot : "");
sprintf(buf, "%s/fstab/%s/type", cmd->dt_dir, mnt_point);
if (access(buf, F_OK) == 0) {
int fd = open(buf, O_RDONLY | O_CLOEXEC);
if ((fd = xopen(buf, O_RDONLY | O_CLOEXEC)) >= 0) {
lstat(buf, &st);
read(fd, partfs, st.st_size);
close(fd);
@ -293,7 +318,7 @@ static bool unxz(int fd, const uint8_t *buf, size_t size) {
}
static int dump_magisk(const char *path, mode_t mode) {
int fd = creat(path, mode);
int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
if (fd < 0)
return 1;
if (!unxz(fd, magisk_xz, sizeof(magisk_xz)))
@ -303,7 +328,7 @@ static int dump_magisk(const char *path, mode_t mode) {
}
static int dump_manager(const char *path, mode_t mode) {
int fd = creat(path, mode);
int fd = open(path, O_WRONLY | O_CREAT | O_TRUNC | O_CLOEXEC, mode);
if (fd < 0)
return 1;
if (!unxz(fd, manager_xz, sizeof(manager_xz)))
@ -353,6 +378,7 @@ static void setup_overlay() {
char buf[128];
int fd;
// Wait for early-init start
while (access(EARLYINIT, F_OK) != 0)
usleep(10);
selinux_builtin_impl();
@ -450,19 +476,19 @@ int main(int argc, char *argv[]) {
if (null > STDERR_FILENO)
close(null);
// Backup stuffs
full_read("/init", &self, &self_sz);
full_read("/.backup/.magisk", &config, &config_sz);
// Communicate with kernel using procfs and sysfs
mkdir("/proc", 0755);
xmount("proc", "/proc", "proc", 0, nullptr);
mkdir("/sys", 0755);
xmount("sysfs", "/sys", "sysfs", 0, nullptr);
struct cmdline cmd;
struct cmdline cmd{};
parse_cmdline(&cmd);
// Backup stuffs
full_read("/init", &self, &self_sz);
full_read("/.backup/.magisk", &config, &config_sz);
/* ***********
* Initialize
* ***********/
@ -480,11 +506,11 @@ int main(int argc, char *argv[]) {
// Revert original init binary
link("/.backup/init", "/init");
rm_rf("/.backup");
}
// Do not go further if system_root device is booting as recovery
if (!cmd.early_boot && access("/sbin/recovery", F_OK) == 0)
exec_init(argv);
// Do not go further if device is booting into recovery
if (access("/sbin/recovery", F_OK) == 0)
exec_init(argv);
}
/* ************
* Early Mount