Build init as C++.

This is just the minimal change to keep it building.

Change-Id: I245c5b8413a1db114576c81462eb5737f5ffcef2
diff --git a/init/util.cpp b/init/util.cpp
new file mode 100644
index 0000000..c484168
--- /dev/null
+++ b/init/util.cpp
@@ -0,0 +1,504 @@
+/*
+ * Copyright (C) 2008 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <errno.h>
+#include <time.h>
+#include <ftw.h>
+
+#include <selinux/label.h>
+#include <selinux/android.h>
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+/* for ANDROID_SOCKET_* */
+#include <cutils/sockets.h>
+
+#include <private/android_filesystem_config.h>
+
+#include "init.h"
+#include "log.h"
+#include "util.h"
+
+/*
+ * android_name_to_id - returns the integer uid/gid associated with the given
+ * name, or -1U on error.
+ */
+static unsigned int android_name_to_id(const char *name)
+{
+    const struct android_id_info *info = android_ids;
+    unsigned int n;
+
+    for (n = 0; n < android_id_count; n++) {
+        if (!strcmp(info[n].name, name))
+            return info[n].aid;
+    }
+
+    return -1U;
+}
+
+/*
+ * decode_uid - decodes and returns the given string, which can be either the
+ * numeric or name representation, into the integer uid or gid. Returns -1U on
+ * error.
+ */
+unsigned int decode_uid(const char *s)
+{
+    unsigned int v;
+
+    if (!s || *s == '\0')
+        return -1U;
+    if (isalpha(s[0]))
+        return android_name_to_id(s);
+
+    errno = 0;
+    v = (unsigned int) strtoul(s, 0, 0);
+    if (errno)
+        return -1U;
+    return v;
+}
+
+/*
+ * create_socket - creates a Unix domain socket in ANDROID_SOCKET_DIR
+ * ("/dev/socket") as dictated in init.rc. This socket is inherited by the
+ * daemon. We communicate the file descriptor's value via the environment
+ * variable ANDROID_SOCKET_ENV_PREFIX<name> ("ANDROID_SOCKET_foo").
+ */
+int create_socket(const char *name, int type, mode_t perm, uid_t uid,
+                  gid_t gid, const char *socketcon)
+{
+    struct sockaddr_un addr;
+    int fd, ret;
+    char *filecon;
+
+    if (socketcon)
+        setsockcreatecon(socketcon);
+
+    fd = socket(PF_UNIX, type, 0);
+    if (fd < 0) {
+        ERROR("Failed to open socket '%s': %s\n", name, strerror(errno));
+        return -1;
+    }
+
+    if (socketcon)
+        setsockcreatecon(NULL);
+
+    memset(&addr, 0 , sizeof(addr));
+    addr.sun_family = AF_UNIX;
+    snprintf(addr.sun_path, sizeof(addr.sun_path), ANDROID_SOCKET_DIR"/%s",
+             name);
+
+    ret = unlink(addr.sun_path);
+    if (ret != 0 && errno != ENOENT) {
+        ERROR("Failed to unlink old socket '%s': %s\n", name, strerror(errno));
+        goto out_close;
+    }
+
+    filecon = NULL;
+    if (sehandle) {
+        ret = selabel_lookup(sehandle, &filecon, addr.sun_path, S_IFSOCK);
+        if (ret == 0)
+            setfscreatecon(filecon);
+    }
+
+    ret = bind(fd, (struct sockaddr *) &addr, sizeof (addr));
+    if (ret) {
+        ERROR("Failed to bind socket '%s': %s\n", name, strerror(errno));
+        goto out_unlink;
+    }
+
+    setfscreatecon(NULL);
+    freecon(filecon);
+
+    chown(addr.sun_path, uid, gid);
+    chmod(addr.sun_path, perm);
+
+    INFO("Created socket '%s' with mode '%o', user '%d', group '%d'\n",
+         addr.sun_path, perm, uid, gid);
+
+    return fd;
+
+out_unlink:
+    unlink(addr.sun_path);
+out_close:
+    close(fd);
+    return -1;
+}
+
+/* reads a file, making sure it is terminated with \n \0 */
+char *read_file(const char *fn, unsigned *_sz)
+{
+    char *data = NULL;
+    int sz;
+    int fd;
+    struct stat sb;
+
+    data = 0;
+    fd = open(fn, O_RDONLY|O_CLOEXEC);
+    if(fd < 0) return 0;
+
+    // for security reasons, disallow world-writable
+    // or group-writable files
+    if (fstat(fd, &sb) < 0) {
+        ERROR("fstat failed for '%s'\n", fn);
+        goto oops;
+    }
+    if ((sb.st_mode & (S_IWGRP | S_IWOTH)) != 0) {
+        ERROR("skipping insecure file '%s'\n", fn);
+        goto oops;
+    }
+
+    sz = lseek(fd, 0, SEEK_END);
+    if(sz < 0) goto oops;
+
+    if(lseek(fd, 0, SEEK_SET) != 0) goto oops;
+
+    data = (char*) malloc(sz + 2);
+    if(data == 0) goto oops;
+
+    if(read(fd, data, sz) != sz) goto oops;
+    close(fd);
+    data[sz] = '\n';
+    data[sz+1] = 0;
+    if(_sz) *_sz = sz;
+    return data;
+
+oops:
+    close(fd);
+    free(data);
+    return 0;
+}
+
+#define MAX_MTD_PARTITIONS 16
+
+static struct {
+    char name[16];
+    int number;
+} mtd_part_map[MAX_MTD_PARTITIONS];
+
+static int mtd_part_count = -1;
+
+static void find_mtd_partitions(void)
+{
+    int fd;
+    char buf[1024];
+    char *pmtdbufp;
+    ssize_t pmtdsize;
+    int r;
+
+    fd = open("/proc/mtd", O_RDONLY|O_CLOEXEC);
+    if (fd < 0)
+        return;
+
+    buf[sizeof(buf) - 1] = '\0';
+    pmtdsize = read(fd, buf, sizeof(buf) - 1);
+    pmtdbufp = buf;
+    while (pmtdsize > 0) {
+        int mtdnum, mtdsize, mtderasesize;
+        char mtdname[16];
+        mtdname[0] = '\0';
+        mtdnum = -1;
+        r = sscanf(pmtdbufp, "mtd%d: %x %x %15s",
+                   &mtdnum, &mtdsize, &mtderasesize, mtdname);
+        if ((r == 4) && (mtdname[0] == '"')) {
+            char *x = strchr(mtdname + 1, '"');
+            if (x) {
+                *x = 0;
+            }
+            INFO("mtd partition %d, %s\n", mtdnum, mtdname + 1);
+            if (mtd_part_count < MAX_MTD_PARTITIONS) {
+                strcpy(mtd_part_map[mtd_part_count].name, mtdname + 1);
+                mtd_part_map[mtd_part_count].number = mtdnum;
+                mtd_part_count++;
+            } else {
+                ERROR("too many mtd partitions\n");
+            }
+        }
+        while (pmtdsize > 0 && *pmtdbufp != '\n') {
+            pmtdbufp++;
+            pmtdsize--;
+        }
+        if (pmtdsize > 0) {
+            pmtdbufp++;
+            pmtdsize--;
+        }
+    }
+    close(fd);
+}
+
+int mtd_name_to_number(const char *name)
+{
+    int n;
+    if (mtd_part_count < 0) {
+        mtd_part_count = 0;
+        find_mtd_partitions();
+    }
+    for (n = 0; n < mtd_part_count; n++) {
+        if (!strcmp(name, mtd_part_map[n].name)) {
+            return mtd_part_map[n].number;
+        }
+    }
+    return -1;
+}
+
+/*
+ * gettime() - returns the time in seconds of the system's monotonic clock or
+ * zero on error.
+ */
+time_t gettime(void)
+{
+    struct timespec ts;
+    int ret;
+
+    ret = clock_gettime(CLOCK_MONOTONIC, &ts);
+    if (ret < 0) {
+        ERROR("clock_gettime(CLOCK_MONOTONIC) failed: %s\n", strerror(errno));
+        return 0;
+    }
+
+    return ts.tv_sec;
+}
+
+int mkdir_recursive(const char *pathname, mode_t mode)
+{
+    char buf[128];
+    const char *slash;
+    const char *p = pathname;
+    int width;
+    int ret;
+    struct stat info;
+
+    while ((slash = strchr(p, '/')) != NULL) {
+        width = slash - pathname;
+        p = slash + 1;
+        if (width < 0)
+            break;
+        if (width == 0)
+            continue;
+        if ((unsigned int)width > sizeof(buf) - 1) {
+            ERROR("path too long for mkdir_recursive\n");
+            return -1;
+        }
+        memcpy(buf, pathname, width);
+        buf[width] = 0;
+        if (stat(buf, &info) != 0) {
+            ret = make_dir(buf, mode);
+            if (ret && errno != EEXIST)
+                return ret;
+        }
+    }
+    ret = make_dir(pathname, mode);
+    if (ret && errno != EEXIST)
+        return ret;
+    return 0;
+}
+
+/*
+ * replaces any unacceptable characters with '_', the
+ * length of the resulting string is equal to the input string
+ */
+void sanitize(char *s)
+{
+    const char* accept =
+            "abcdefghijklmnopqrstuvwxyz"
+            "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+            "0123456789"
+            "_-.";
+
+    if (!s)
+        return;
+
+    while (*s) {
+        s += strspn(s, accept);
+        if (*s) *s++ = '_';
+    }
+}
+
+void make_link(const char *oldpath, const char *newpath)
+{
+    int ret;
+    char buf[256];
+    char *slash;
+    int width;
+
+    slash = strrchr(newpath, '/');
+    if (!slash)
+        return;
+    width = slash - newpath;
+    if (width <= 0 || width > (int)sizeof(buf) - 1)
+        return;
+    memcpy(buf, newpath, width);
+    buf[width] = 0;
+    ret = mkdir_recursive(buf, 0755);
+    if (ret)
+        ERROR("Failed to create directory %s: %s (%d)\n", buf, strerror(errno), errno);
+
+    ret = symlink(oldpath, newpath);
+    if (ret && errno != EEXIST)
+        ERROR("Failed to symlink %s to %s: %s (%d)\n", oldpath, newpath, strerror(errno), errno);
+}
+
+void remove_link(const char *oldpath, const char *newpath)
+{
+    char path[256];
+    ssize_t ret;
+    ret = readlink(newpath, path, sizeof(path) - 1);
+    if (ret <= 0)
+        return;
+    path[ret] = 0;
+    if (!strcmp(path, oldpath))
+        unlink(newpath);
+}
+
+int wait_for_file(const char *filename, int timeout)
+{
+    struct stat info;
+    time_t timeout_time = gettime() + timeout;
+    int ret = -1;
+
+    while (gettime() < timeout_time && ((ret = stat(filename, &info)) < 0))
+        usleep(10000);
+
+    return ret;
+}
+
+void open_devnull_stdio(void)
+{
+    int fd;
+    static const char *name = "/dev/__null__";
+    if (mknod(name, S_IFCHR | 0600, (1 << 8) | 3) == 0) {
+        fd = open(name, O_RDWR);
+        unlink(name);
+        if (fd >= 0) {
+            dup2(fd, 0);
+            dup2(fd, 1);
+            dup2(fd, 2);
+            if (fd > 2) {
+                close(fd);
+            }
+            return;
+        }
+    }
+
+    exit(1);
+}
+
+void get_hardware_name(char *hardware, unsigned int *revision) {
+  // Hardware string was provided on kernel command line.
+  if (hardware[0]) {
+    return;
+  }
+
+  FILE* fp = fopen("/proc/cpuinfo", "re");
+  if (fp == NULL) {
+    return;
+  }
+  char buf[1024];
+  while (fgets(buf, sizeof(buf), fp) != NULL) {
+    if (strncmp(buf, "Hardware", 8) == 0) {
+      const char* hw = strstr(buf, ": ");
+      if (hw) {
+        hw += 2;
+        size_t n = 0;
+        while (*hw) {
+          if (!isspace(*hw)) {
+            hardware[n++] = tolower(*hw);
+          }
+          hw++;
+          if (n == 31) break;
+        }
+        hardware[n] = 0;
+      }
+    } else if (strncmp(buf, "Revision", 8) == 0) {
+      const char* rev = strstr(buf, ": ");
+      if (rev) {
+        *revision = strtoul(rev + 2, 0, 16);
+      }
+    }
+  }
+  fclose(fp);
+}
+
+void import_kernel_cmdline(int in_qemu,
+                           void (*import_kernel_nv)(char *name, int in_qemu))
+{
+    char cmdline[2048];
+    char *ptr;
+    int fd;
+
+    fd = open("/proc/cmdline", O_RDONLY | O_CLOEXEC);
+    if (fd >= 0) {
+        int n = read(fd, cmdline, sizeof(cmdline) - 1);
+        if (n < 0) n = 0;
+
+        /* get rid of trailing newline, it happens */
+        if (n > 0 && cmdline[n-1] == '\n') n--;
+
+        cmdline[n] = 0;
+        close(fd);
+    } else {
+        cmdline[0] = 0;
+    }
+
+    ptr = cmdline;
+    while (ptr && *ptr) {
+        char *x = strchr(ptr, ' ');
+        if (x != 0) *x++ = 0;
+        import_kernel_nv(ptr, in_qemu);
+        ptr = x;
+    }
+}
+
+int make_dir(const char *path, mode_t mode)
+{
+    int rc;
+
+    char *secontext = NULL;
+
+    if (sehandle) {
+        selabel_lookup(sehandle, &secontext, path, mode);
+        setfscreatecon(secontext);
+    }
+
+    rc = mkdir(path, mode);
+
+    if (secontext) {
+        int save_errno = errno;
+        freecon(secontext);
+        setfscreatecon(NULL);
+        errno = save_errno;
+    }
+
+    return rc;
+}
+
+int restorecon(const char* pathname)
+{
+    return selinux_android_restorecon(pathname, 0);
+}
+
+int restorecon_recursive(const char* pathname)
+{
+    return selinux_android_restorecon(pathname, SELINUX_ANDROID_RESTORECON_RECURSE);
+}