Correct PPTP server firewall rules chain.

[tomato/davidwu.git] / release / src / router / shared / usb.c

/*

        Tomato Firmware
        USB Support Module

*/
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <ctype.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <stdarg.h>
#include <syslog.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <dirent.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#include <sys/sysinfo.h>
#include <sys/types.h>

#include <bcmnvram.h>
#include <bcmdevs.h>
#include <wlutils.h>

#include "shutils.h"
#include "shared.h"


/* Serialize using fcntl() calls 
 */

int file_lock(char *tag)
{
        char fn[64];
        struct flock lock;
        int lockfd = -1;
        pid_t lockpid;

        sprintf(fn, "/var/lock/%s.lock", tag);
        if ((lockfd = open(fn, O_CREAT | O_RDWR, 0666)) < 0)
                goto lock_error;

        pid_t pid = getpid();
        if (read(lockfd, &lockpid, sizeof(pid_t))) {
                // check if we already hold a lock
                if (pid == lockpid) {
                        // don't close the file here as that will release all locks
                        return -1;
                }
        }

        memset(&lock, 0, sizeof(lock));
        lock.l_type = F_WRLCK;
        lock.l_pid = pid;

        if (fcntl(lockfd, F_SETLKW, &lock) < 0) {
                close(lockfd);
                goto lock_error;
        }

        lseek(lockfd, 0, SEEK_SET);
        write(lockfd, &pid, sizeof(pid_t));
        return lockfd;
lock_error:
        // No proper error processing
        syslog(LOG_DEBUG, "Error %d locking %s, proceeding anyway", errno, fn);
        return -1;
}

void file_unlock(int lockfd)
{
        if (lockfd >= 0) {
                ftruncate(lockfd, 0);
                close(lockfd);
        }
}


/* Execute a function for each disc partition on the specified controller.
 *
 * Directory /dev/discs/ looks like this:
 * disc0 -> ../scsi/host0/bus0/target0/lun0/
 * disc1 -> ../scsi/host1/bus0/target0/lun0/
 * disc2 -> ../scsi/host2/bus0/target0/lun0/
 * disc3 -> ../scsi/host2/bus0/target0/lun1/
 *
 * Scsi host 2 supports multiple drives.
 * Scsi host 0 & 1 support one drive.
 *
 * For attached drives, like this.  If not attached, there is no "part#" item.
 * Here, only one drive, with 2 partitions, is plugged in.
 * /dev/discs/disc0/disc
 * /dev/discs/disc0/part1
 * /dev/discs/disc0/part2
 * /dev/discs/disc1/disc
 * /dev/discs/disc2/disc
 *
 * Which is the same as:
 * /dev/scsi/host0/bus0/target0/lun0/disc
 * /dev/scsi/host0/bus0/target0/lun0/part1
 * /dev/scsi/host0/bus0/target0/lun0/part2
 * /dev/scsi/host1/bus0/target0/lun0/disc
 * /dev/scsi/host2/bus0/target0/lun0/disc
 * /dev/scsi/host2/bus0/target0/lun1/disc
 *
 * Implementation notes:
 * Various mucking about with a disc that just got plugged in or unplugged
 * will make the scsi subsystem try a re-validate, and read the partition table of the disc.
 * This will make sure the partitions show up.
 *
 * It appears to try to do the revalidate and re-read & update the partition
 * information when this code does the "readdir of /dev/discs/disc0/?".  If the
 * disc has any mounted partitions the revalidate will be rejected.  So the
 * current partition info will remain.  On an unplug event, when it is doing the
 * readdir's, it will try to do the revalidate as we are doing the readdir's.
 * But luckily they'll be rejected, otherwise the later partitions will disappear as
 * soon as we get the first one.
 * But be very careful!  If something goes not exactly right, the partition entries
 * will disappear before we've had a chance to unmount from them.
 *
 * To avoid this automatic revalidation, we go through /proc/partitions looking for the partitions
 * that /dev/discs point to.  That will avoid the implicit revalidate attempt.
 * 
 * If host < 0, do all hosts.   If >= 0, it is the host number to do.
 *
 */

/* check if the block device has no partition */
int is_no_partition(const char *discname)
{
        FILE *procpt;
        char line[128], ptname[32];
        int ma, mi, sz;
        int count = 0;

        if ((procpt = fopen("/proc/partitions", "r"))) {
                while (fgets(line, sizeof(line), procpt)) {
                        if (sscanf(line, " %d %d %d %[^\n ]", &ma, &mi, &sz, ptname) != 4)
                                continue;
                        if (strstr(ptname, discname))
                                count++;
                }
        }

        return (count == 1);
}

int exec_for_host(int host, int obsolete, uint flags, host_exec func)
{
        DIR *usb_dev_disc;
        char bfr[256];  /* Will be: /dev/discs/disc#                                    */
        char ptname[32];/* Will be: discDN_PN                                           */
        char dsname[16];/* Will be: discDN                                              */
        int host_no;    /* SCSI controller/host # */
        struct dirent *dp;
        FILE *prt_fp;
        int siz;
        char line[256];
        int result = 0;

        flags |= EFH_1ST_HOST;

#ifdef LINUX26
        char hostbuf[16];
        DIR *dir_host;

        /*
         * Scsi block devices in kernel 2.6 (for attached devices) can be found as
         *      /sys/bus/scsi/devices/<host_no>:x:x:x/block:[sda|sdb|...]
         */
        if ((usb_dev_disc = opendir("/sys/bus/scsi/devices"))) {
                sprintf(hostbuf, "%d:", host);

                while ((dp = readdir(usb_dev_disc))) {
                        if (host >= 0 && strncmp(dp->d_name, hostbuf, strlen(hostbuf)) != 0)
                                continue;
                        if (sscanf(dp->d_name, "%d:%*s:%*s:%*s", &host_no) != 1)
                                continue;
                        sprintf(bfr, "/sys/bus/scsi/devices/%s", dp->d_name);
                        if ((dir_host = opendir(bfr))) {
                                while ((dp = readdir(dir_host))) {
                                        if (strncmp(dp->d_name, "block:", 6) != 0)
                                                continue;
                                        strncpy(dsname, dp->d_name + 6, sizeof(dsname));
                                        siz = strlen(dsname);

                                        flags |= EFH_1ST_DISC;
                                        if (func && (prt_fp = fopen("/proc/partitions", "r"))) {
                                                while (fgets(line, sizeof(line) - 2, prt_fp)) {
                                                        if (sscanf(line, " %*s %*s %*s %s", ptname) == 1) {
                                                                if (strncmp(ptname, dsname, siz) == 0) {
                                                                        if ((strcmp(ptname, dsname) == 0) && !is_no_partition(dsname))
                                                                                continue;
                                                                        sprintf(line, "/dev/%s", ptname);
                                                                        result = (*func)(line, host_no, dsname, ptname, flags) || result;
                                                                        flags &= ~(EFH_1ST_HOST | EFH_1ST_DISC);
                                                                }
                                                        }
                                                }
                                                fclose(prt_fp);
                                        }
                                }
                                closedir(dir_host);
                        }
                }
                closedir(usb_dev_disc);
        }

#else   /* !LINUX26 */
        char link[256]; /* Will be: ../scsi/host#/bus0/target0/lun#  that bfr links to. */
                        /* When calling the func, will be: /dev/discs/disc#/part#       */
        char bfr2[128]; /* Will be: /dev/discs/disc#/disc     for the BLKRRPART.        */
        char *cp;
        int len;
        int disc_num;   /* Disc # */
        int part_num;   /* Parition # */
        char *mp;       /* Ptr to after any leading ../ path */

        if ((usb_dev_disc = opendir(DEV_DISCS_ROOT))) {
                while ((dp = readdir(usb_dev_disc))) {
                        sprintf(bfr, "%s/%s", DEV_DISCS_ROOT, dp->d_name);
                        if (strncmp(dp->d_name, "disc", 4) != 0)
                                continue;

                        disc_num = atoi(dp->d_name + 4);
                        len = readlink(bfr, link, sizeof(link) - 1);
                        if (len < 0)
                                continue;

                        link[len] = 0;
                        cp = strstr(link, "/scsi/host");
                        if (!cp)
                                continue;

                        host_no = atoi(cp + 10);
                        if (host >= 0 && host_no != host)
                                continue;

                        /* We have found a disc that is on this controller.
                         * Loop thru all the partitions on this disc.
                         * The new way, reading thru /proc/partitions.
                         */
                        mp = link;
                        if ((cp = strstr(link, "../")) != NULL)
                                mp = cp + 3;
                        siz = strlen(mp);

                        flags |= EFH_1ST_DISC;
                        if (func && (prt_fp = fopen("/proc/partitions", "r"))) {
                                while (fgets(line, sizeof(line) - 2, prt_fp)) {
                                        if (sscanf(line, " %*s %*s %*s %s", bfr2) == 1 &&
                                            strncmp(bfr2, mp, siz) == 0)
                                        {
                                                if ((cp = strstr(bfr2, "/part"))) {
                                                        part_num = atoi(cp + 5);
                                                        sprintf(line, "%s/part%d", bfr, part_num);
                                                        sprintf(dsname, "disc%d", disc_num);
                                                        sprintf(ptname, "disc%d_%d", disc_num, part_num);
                                                }
                                                else if ((cp = strstr(bfr2, "/disc"))) {
                                                        *(++cp) = 0;
                                                        if (!is_no_partition(bfr2))
                                                                continue;
                                                        sprintf(line, "%s/disc", bfr);
                                                        sprintf(dsname, "disc%d", disc_num);
                                                        strcpy(ptname, dsname);
                                                }
                                                else {
                                                        continue;
                                                }
                                                result = (*func)(line, host_no, dsname, ptname, flags) || result;
                                                flags &= ~(EFH_1ST_HOST | EFH_1ST_DISC);
                                        }
                                }
                                fclose(prt_fp);
                        }
                }
                closedir(usb_dev_disc);
        }

#endif  /* LINUX26 */

        return result;
}

/* Concept taken from the e2fsprogs/ismounted.c.
 * Find wherever 'file' (actually: device) is mounted.
 * Either the exact same device-name, or another device-name.
 * The latter is detected by comparing the rdev or dev&inode.
 * So aliasing won't fool us---we'll still find if it's mounted.
 * Return its mnt entry.
 * In particular, the caller would look at the mnt->mountpoint.
 *
 * Find the matching devname(s) in mounts or swaps.
 * If func is supplied, call it for each match.  If not, return mnt on the first match.
 */

static inline int is_same_device(char *fsname, dev_t file_rdev, dev_t file_dev, ino_t file_ino)
{
        struct stat st_buf;

        if (stat(fsname, &st_buf) == 0) {
                if (S_ISBLK(st_buf.st_mode)) {
                        if (file_rdev && (file_rdev == st_buf.st_rdev))
                                return 1;
                }
                else {
                        if (file_dev && ((file_dev == st_buf.st_dev) &&
                                (file_ino == st_buf.st_ino)))
                                return 1;
                        /* Check for [swap]file being on the device. */
                        if (file_dev == 0 && file_ino == 0 && file_rdev == st_buf.st_dev)
                                return 1;
                }
        }
        return 0;
}


struct mntent *findmntents(char *file, int swp, int (*func)(struct mntent *mnt, uint flags), uint flags)
{
        struct mntent   *mnt;
        struct stat     st_buf;
        dev_t           file_dev=0, file_rdev=0;
        ino_t           file_ino=0;
        FILE            *f;

        if ((f = setmntent(swp ? "/proc/swaps": "/proc/mounts", "r")) == NULL)
                return NULL;

        if (stat(file, &st_buf) == 0) {
                if (S_ISBLK(st_buf.st_mode)) {
                        file_rdev = st_buf.st_rdev;
                }
                else {
                        file_dev = st_buf.st_dev;
                        file_ino = st_buf.st_ino;
                }
        }
        while ((mnt = getmntent(f)) != NULL) {
                /* Always ignore rootfs mount */
                if (strcmp(mnt->mnt_fsname, "rootfs") == 0)
                        continue;

                if (strcmp(file, mnt->mnt_fsname) == 0 ||
                    strcmp(file, mnt->mnt_dir) == 0 ||
                    is_same_device(mnt->mnt_fsname, file_rdev , file_dev, file_ino)) {
                        if (func == NULL)
                                break;
                        (*func)(mnt, flags);
                }
        }

        endmntent(f);
        return mnt;
}


//#define SAME_AS_KERNEL
/* Simulate a hotplug event, as if a USB storage device
 * got plugged or unplugged.
 * Either use a hardcoded program name, or the same
 * hotplug program that the kernel uses for a real event.
 */
void add_remove_usbhost(char *host, int add)
{
        setenv("ACTION", add ? "add" : "remove", 1);
        setenv("SCSI_HOST", host, 1);
        setenv("PRODUCT", host, 1);
        setenv("INTERFACE", "TOMATO/0", 1);
#ifdef SAME_AS_KERNEL
        char pgm[256] = "/sbin/hotplug usb";
        char *p;
        int fd = open("/proc/sys/kernel/hotplug", O_RDONLY);
        if (fd) {
                if (read(fd, pgm, sizeof(pgm) - 5) >= 0) {
                        if ((p = strchr(pgm, '\n')) != NULL)
                                *p = 0;
                        strcat(pgm, " usb");
                }
                close(fd);
        }
        system(pgm);
#else
        // don't use value from /proc/sys/kernel/hotplug 
        // since it may be overriden by a user.
        system("/sbin/hotplug usb");
#endif
        unsetenv("INTERFACE");
        unsetenv("PRODUCT");
        unsetenv("SCSI_HOST");
        unsetenv("ACTION");
}


/****************************************************/
/* Use busybox routines to get labels for fat & ext */
/* Probe for label the same way that mount does.    */
/****************************************************/

#define VOLUME_ID_LABEL_SIZE            64
#define VOLUME_ID_UUID_SIZE             36
#define SB_BUFFER_SIZE                  0x11000

struct volume_id {
        int             fd;
        int             error;
        size_t          sbbuf_len;
        size_t          seekbuf_len;
        uint8_t         *sbbuf;
        uint8_t         *seekbuf;
        uint64_t        seekbuf_off;
        char            label[VOLUME_ID_LABEL_SIZE+1];
        char            uuid[VOLUME_ID_UUID_SIZE+1];
};

extern void volume_id_set_uuid();
extern void *volume_id_get_buffer();
extern void volume_id_free_buffer();
extern int volume_id_probe_ext();
extern int volume_id_probe_vfat();
extern int volume_id_probe_ntfs();
extern int volume_id_probe_linux_swap();

/* Put the label in *label and uuid in *uuid.
 * Return fstype if determined.
 */
char *find_label_or_uuid(char *dev_name, char *label, char *uuid)
{
        struct volume_id id;
        char *fstype = NULL;

        memset(&id, 0x00, sizeof(id));
        if (label) *label = 0;
        if (uuid) *uuid = 0;
        if ((id.fd = open(dev_name, O_RDONLY)) < 0)
                return NULL;

        volume_id_get_buffer(&id, 0, SB_BUFFER_SIZE);

        if (!id.error && volume_id_probe_linux_swap(&id) == 0)
                fstype = "swap";
        else if (!id.error && volume_id_probe_vfat(&id) == 0)
                fstype = "vfat";
        else if (!id.error && volume_id_probe_ext(&id) == 0)
                fstype = ((id.sbbuf[0x460] & 0x0008 /* JOURNAL_DEV */) != 0 ||
                          (id.sbbuf[0x45c] & 0x0004 /* HAS_JOURNAL */) != 0) ? "ext3" : "ext2";
        else if (!id.error && volume_id_probe_ntfs(&id) == 0)
                fstype = "ntfs";
        else if (!id.error)
                fstype = "unknown";

        volume_id_free_buffer(&id);
        if (label && (*id.label != 0))
                strcpy(label, id.label);
        if (uuid && (*id.uuid != 0))
                strcpy(uuid, id.uuid);
        close(id.fd);
        return (fstype);
}

void *xmalloc(size_t siz)
{
        return (malloc(siz));
}

void *xrealloc(void *old, size_t size)
{
        return realloc(old, size);
}

ssize_t full_read(int fd, void *buf, size_t len)
{
        return read(fd, buf, len);
}