C++ PLOGE函数代码示例

static void mount_emulated_storage(int user_id) {
    const char *emulated_source = getenv("EMULATED_STORAGE_SOURCE");
    const char *emulated_target = getenv("EMULATED_STORAGE_TARGET");
    const char* legacy = getenv("EXTERNAL_STORAGE");

    if (!emulated_source || !emulated_target) {
        // No emulated storage is present
        return;
    }

    // Create a second private mount namespace for our process
    if (unshare(CLONE_NEWNS) < 0) {
        PLOGE("unshare");
        return;
    }

    if (mount("rootfs", "/", NULL, MS_SLAVE | MS_REC, NULL) < 0) {
        PLOGE("mount rootfs as slave");
        return;
    }

    // /mnt/shell/emulated -> /storage/emulated
    if (mount(emulated_source, emulated_target, NULL, MS_BIND, NULL) < 0) {
        PLOGE("mount emulated storage");
    }

    char target_user[PATH_MAX];
    snprintf(target_user, PATH_MAX, "%s/%d", emulated_target, user_id);

    // /mnt/shell/emulated/<user> -> /storage/emulated/legacy
    if (mount(target_user, legacy, NULL, MS_BIND | MS_REC, NULL) < 0) {
        PLOGE("mount legacy path");
    }
}

static int socket_accept(int serv_fd) {
    struct timeval tv;
    fd_set fds;
    int fd, rc;

    /* Wait 20 seconds for a connection, then give up. */
    tv.tv_sec = 20;
    tv.tv_usec = 0;
    FD_ZERO(&fds);
    FD_SET(serv_fd, &fds);
    do {
        rc = select(serv_fd + 1, &fds, NULL, NULL, &tv);
    } while (rc < 0 && errno == EINTR);
    if (rc < 1) {
        PLOGE("select");
        return -1;
    }

    fd = accept(serv_fd, NULL, NULL);
    if (fd < 0) {
        PLOGE("accept");
        return -1;
    }

    return fd;
}

static void write_int(int fd, int val) {
    int written = write(fd, &val, sizeof(int));
    if (written != sizeof(int)) {
        PLOGE("unable to write int");
        exit(-1);
    }
}

static void allow(char *shell, mode_t mask)
{
    struct su_initiator *from = &su_from;
    struct su_request *to = &su_to;
    char *exe = NULL;

    umask(mask);
    send_intent(&su_from, &su_to, "", 1, 1);

    if (!strcmp(shell, "")) {
        strcpy(shell , "/system/bin/sh");
    }
    exe = strrchr (shell, '/') + 1;
    setresgid(to->uid, to->uid, to->uid);
    setresuid(to->uid, to->uid, to->uid);
    LOGD("%u %s executing %u %s using shell %s : %s", from->uid, from->bin,
            to->uid, to->command, shell, exe);
    if (strcmp(to->command, DEFAULT_COMMAND)) {
        execl(shell, exe, "-c", to->command, (char*)NULL);
    } else {
        execl(shell, exe, "-", (char*)NULL);
    }
    PLOGE("exec");
    exit(EXIT_SUCCESS);
}

static void populate_environment(const struct su_context *ctx)
{
    struct passwd *pw;
    char *val;

    if (ctx->to.keepenv)
        return;

    pw = getpwuid(ctx->to.uid);
    if (pw) {
        setenv("HOME", pw->pw_dir, 1);
        setenv("SHELL", ctx->to.shell, 1);
        if (ctx->to.login || ctx->to.uid) {
            setenv("USER", pw->pw_name, 1);
            setenv("LOGNAME", pw->pw_name, 1);
        }
    }

    if (ctx->sdk_version >= 14) {
        val = get_parent_env(&ctx->from, "LD_LIBRARY_PATH", sizeof("LD_LIBRARY_PATH") - 1);
        if (val)
            if (setenv("LD_LIBRARY_PATH", val, 1))
                PLOGE("setenv(LD_LIBRARY_PATH)");
    }
}

static void prepare_bind() {
	int ret = 0;
	//Check if there is a use to mount bind
	if(access("/system/xbin/su", R_OK) != 0)
		return;

	ret = mkdir("/dev/su", 0700);

	ret = copy_file("/sbin/su", "/dev/su/su", 0755);
	if(ret) {
		PLOGE("Failed to copy su");
		return;
	}
	chmod("/dev/su/su", 0755);

	ret = setfilecon("/dev/su/su", "u:object_r:system_file:s0");
	if(ret) {
		LOGE("Failed to set file context");
		return;
	}

	ret = mount("/dev/su/su", "/system/xbin/su", "", MS_BIND, NULL);
	if(ret) {
		LOGE("Failed to mount bind");
		return;
	}
}

static void socket_cleanup(struct su_context *ctx) {
    if (ctx && ctx->sock_path[0]) {
        if (unlink(ctx->sock_path))
            PLOGE("unlink (%s)", ctx->sock_path);
        ctx->sock_path[0] = 0;
    }
}

static void sighandler(int sig) {
	(void)sig;
    restore_stdin();

    // Assume we'll only be called before death
    // See note before sigaction() in set_stdin_raw()
    //
    // Now, close all standard I/O to cause the pumps
    // to exit so we can continue and retrieve the exit
    // code
    close(STDIN_FILENO);
    close(STDOUT_FILENO);
    close(STDERR_FILENO);

    // Put back all the default handlers
    struct sigaction act;
    int i;

    memset(&act, '\0', sizeof(act));
    act.sa_handler = SIG_DFL;
    for (i = 0; quit_signals[i]; i++) {
        if (sigaction(quit_signals[i], &act, NULL) < 0) {
            PLOGE("Error removing signal handler");
            continue;
        }
    }
}

static void socket_cleanup(void)
{
    if (socket_path[0]) {
        if (unlink(socket_path))
            PLOGE("unlink (%s)", socket_path);
        socket_path[0] = 0;
    }
}

static char *get_parent_env(const struct su_initiator *from, const char *var, size_t varlen)
{
    char path[PATH_MAX];
    char env[8129];
    char *val = NULL;
    char *p;
    int fd = -1;
    int len, rest, i, l;

    snprintf(path, sizeof(path), "/proc/%u/environ", from->pid);
    fd = open(path, O_RDONLY);
    if (fd < 0) {
        PLOGE("Opening environment");
        return NULL;
    }

    rest = 0;
    do {
        len = read(fd, env + rest, sizeof(env) - rest);
        if (len < 0)
            PLOGE("Reading environment");
        if (len <= 0)
            break;
        len += rest;

        for (i = 0; i < len; i += l) {
            l = strnlen(env + i, len - i) + 1;
            if (i + l > len)
                break;

            if (!strncmp(var, env + i, varlen) && env[i + varlen] == '=') {
                p = env + i + varlen + 1;
                val = malloc(l - varlen - 1);
                if (val)
                    strncpy(val, p, l - varlen - 1);
                goto out;
            }
        }
        rest = len - i;
        memmove(env, env + i, rest);
    } while (1);
out:
    close(fd);

    return val;
}

void set_identity(unsigned int uid) {
    /*
     * Set effective uid back to root, otherwise setres[ug]id will fail
     * if uid isn't root.
     */
    if (seteuid(0)) {
        PLOGE("seteuid (root)");
        exit(EXIT_FAILURE);
    }
    if (setresgid(uid, uid, uid)) {
        PLOGE("setresgid (%u)", uid);
        exit(EXIT_FAILURE);
    }
    if (setresuid(uid, uid, uid)) {
        PLOGE("setresuid (%u)", uid);
        exit(EXIT_FAILURE);
    }
}

static void write_string(int fd, char* val) {
    int len = strlen(val);
    write_int(fd, len);
    int written = write(fd, val, len);
    if (written != len) {
        PLOGE("unable to write string");
        exit(-1);
    }
}

static int socket_create_temp(char *path, size_t len) {
    int fd;
    struct sockaddr_un sun;

    fd = socket(AF_LOCAL, SOCK_STREAM, 0);
    if (fd < 0) {
        PLOGE("socket");
        return -1;
    }
    if (fcntl(fd, F_SETFD, FD_CLOEXEC)) {
        PLOGE("fcntl FD_CLOEXEC");
        goto err;
    }

    memset(&sun, 0, sizeof(sun));
    sun.sun_family = AF_LOCAL;
    snprintf(path, len, "%s/.socket%d", REQUESTOR_CACHE_PATH, getpid());
    memset(sun.sun_path, 0, sizeof(sun.sun_path));
    snprintf(sun.sun_path, sizeof(sun.sun_path), "%s", path);

    /*
     * Delete the socket to protect from situations when
     * something bad occured previously and the kernel reused pid from that process.
     * Small probability, isn't it.
     */
    unlink(sun.sun_path);

    if (bind(fd, (struct sockaddr*)&sun, sizeof(sun)) < 0) {
        PLOGE("bind");
        goto err;
    }

    if (listen(fd, 1) < 0) {
        PLOGE("listen");
        goto err;
    }

    return fd;
err:
    close(fd);
    return -1;
}

static int run_daemon_child(int infd, int outfd, int errfd, int argc, char** argv) {
    if (-1 == dup2(outfd, STDOUT_FILENO)) {
        PLOGE("dup2 child outfd");
        exit(-1);
    }

    if (-1 == dup2(errfd, STDERR_FILENO)) {
        PLOGE("dup2 child errfd");
        exit(-1);
    }

    if (-1 == dup2(infd, STDIN_FILENO)) {
        PLOGE("dup2 child infd");
        exit(-1);
    }

    close(infd);
    close(outfd);
    close(errfd);

    return su_main_nodaemon(argc, argv);
}

static int socket_send_request(int fd, const struct su_context *ctx)
{
    size_t len;
    size_t bin_size, cmd_size;
    char *cmd;

#define write_token(fd, data)				\
do {							\
	uint32_t __data = htonl(data);			\
	size_t __count = sizeof(__data);		\
	size_t __len = write((fd), &__data, __count);	\
	if (__len != __count) {				\
		PLOGE("write(" #data ")");		\
		return -1;				\
	}						\
} while (0)

    write_token(fd, PROTO_VERSION);
    write_token(fd, PATH_MAX);
    write_token(fd, ARG_MAX);
    write_token(fd, ctx->from.uid);
    write_token(fd, ctx->to.uid);
    bin_size = strlen(ctx->from.bin) + 1;
    write_token(fd, bin_size);
    len = write(fd, ctx->from.bin, bin_size);
    if (len != bin_size) {
        PLOGE("write(bin)");
        return -1;
    }
    cmd = get_command(&ctx->to);
    cmd_size = strlen(cmd) + 1;
    write_token(fd, cmd_size);
    len = write(fd, cmd, cmd_size);
    if (len != cmd_size) {
        PLOGE("write(cmd)");
        return -1;
    }
    return 0;
}