fuse-helpers.c

/*
   Copyright (c) 2010-2012 Red Hat, Inc. <http://www.redhat.com>
   This file is part of GlusterFS.

   This file is licensed to you under your choice of the GNU Lesser
   General Public License, version 3 or any later version (LGPLv3 or
   later), or the GNU General Public License, version 2 (GPLv2), in all
   cases as published by the Free Software Foundation.
*/
#ifdef __NetBSD__
#define _KMEMUSER
#endif

#if defined(GF_SOLARIS_HOST_OS)
#include <sys/procfs.h>
#elif defined(__FreeBSD__)
#include <sys/types.h>
#include <libutil.h>
#elif defined(CTL_KERN)
#include <sys/sysctl.h>
#endif
#include <pwd.h>

#include "fuse-bridge.h"

static void
fuse_resolve_wipe(fuse_resolve_t *resolve)
{
    GF_FREE((void *)resolve->path);

    GF_FREE((void *)resolve->bname);

    if (resolve->fd)
        fd_unref(resolve->fd);

    loc_wipe(&resolve->resolve_loc);

    if (resolve->hint) {
        inode_unref(resolve->hint);
        resolve->hint = 0;
    }

    if (resolve->parhint) {
        inode_unref(resolve->parhint);
        resolve->parhint = 0;
    }
}

void
free_fuse_state(fuse_state_t *state)
{
    xlator_t *this = NULL;
    fuse_private_t *priv = NULL;
    uint64_t winds = 0;
    char switched = 0;

    this = state->this;

    priv = this->private;

    loc_wipe(&state->loc);

    loc_wipe(&state->loc2);

    if (state->xdata) {
        dict_unref(state->xdata);
        state->xdata = (void *)0xaaaaeeee;
    }
    if (state->xattr)
        dict_unref(state->xattr);

    if (state->name) {
        GF_FREE(state->name);
        state->name = NULL;
    }
    if (state->fd) {
        fd_unref(state->fd);
        state->fd = (void *)0xfdfdfdfd;
    }
    if (state->finh) {
        GF_FREE(state->finh);
        state->finh = NULL;
    }

    fuse_resolve_wipe(&state->resolve);
    fuse_resolve_wipe(&state->resolve2);

    pthread_mutex_lock(&priv->sync_mutex);
    {
        winds = --state->active_subvol->winds;
        switched = state->active_subvol->switched;
    }
    pthread_mutex_unlock(&priv->sync_mutex);

    if ((winds == 0) && (switched)) {
        xlator_notify(state->active_subvol, GF_EVENT_PARENT_DOWN,
                      state->active_subvol, NULL);
    }

#ifdef DEBUG
    memset(state, 0x90, sizeof(*state));
#endif
    GF_FREE(state);
    state = NULL;
}

fuse_state_t *
get_fuse_state(xlator_t *this, fuse_in_header_t *finh)
{
    fuse_state_t *state = NULL;
    xlator_t *active_subvol = NULL;
    fuse_private_t *priv = NULL;

    state = (void *)GF_CALLOC(1, sizeof(*state), gf_fuse_mt_fuse_state_t);
    if (!state)
        return NULL;

    state->this = THIS;
    priv = this->private;

    pthread_mutex_lock(&priv->sync_mutex);
    {
        while (priv->handle_graph_switch)
            pthread_cond_wait(&priv->migrate_cond, &priv->sync_mutex);
        active_subvol = fuse_active_subvol(state->this);
        active_subvol->winds++;
    }
    pthread_mutex_unlock(&priv->sync_mutex);

    state->active_subvol = active_subvol;
    state->itable = active_subvol->itable;

    state->pool = this->ctx->pool;
    state->finh = finh;
    state->this = this;

    LOCK_INIT(&state->lock);

    return state;
}

void
frame_fill_groups(call_frame_t *frame)
{
#if defined(GF_LINUX_HOST_OS)
    xlator_t *this = frame->this;
    fuse_private_t *priv = this->private;
    char filename[32];
    char line[4096];
    char *ptr = NULL;
    long int id = 0;
    char *saveptr = NULL;
    char *endptr = NULL;
    int ret = 0;
    int ngroups = 0;
    gid_t *mygroups = NULL;

    if (priv->resolve_gids) {
        struct passwd pwent;
        char mystrs[1024];
        struct passwd *result;

        if (getpwuid_r(frame->root->uid, &pwent, mystrs, sizeof(mystrs),
                       &result) != 0) {
            gf_log(this->name, GF_LOG_ERROR,
                   "getpwuid_r(%u) "
                   "failed",
                   frame->root->uid);
            return;
        }
        if (result == 0) {
            gf_log(this->name, GF_LOG_ERROR,
                   "getpwuid_r(%u): "
                   "no matching record",
                   frame->root->uid);
            return;
        }

        ngroups = gf_getgrouplist(result->pw_name, frame->root->gid, &mygroups);
        if (ngroups == -1) {
            gf_log(this->name, GF_LOG_ERROR,
                   "could not map %s to "
                   "group list (ngroups %d, max %d)",
                   result->pw_name, ngroups, GF_MAX_AUX_GROUPS);
            return;
        }

        call_stack_set_groups(frame->root, ngroups, &mygroups);
    } else {
        FILE *fp = NULL;

        ret = snprintf(filename, sizeof filename, "/proc/%d/status",
                       frame->root->pid);
        if (ret >= sizeof filename) {
            gf_log(this->name, GF_LOG_ERROR, "procfs path exceeds buffer size");
            goto out;
        }

        fp = fopen(filename, "r");
        if (!fp) {
            gf_log(this->name, GF_LOG_ERROR, "failed to open %s: %s", filename,
                   strerror(errno));
            goto out;
        }

        for (;;) {
            gf_boolean_t found_groups = _gf_false;
            int idx = 0;

            if (call_stack_alloc_groups(frame->root, ngroups) != 0) {
                gf_log(this->name, GF_LOG_ERROR,
                       "failed to allocate gid buffer");
                goto out;
            }

            while ((ptr = fgets(line, sizeof line, fp))) {
                if (strncmp(ptr, "Groups:", 7) == 0) {
                    found_groups = _gf_true;
                    break;
                }
            }
            if (!found_groups) {
                gf_log(this->name, GF_LOG_ERROR, "cannot find gid list in %s",
                       filename);
                break;
            }
            ptr = line + 8;

            for (ptr = strtok_r(ptr, " \t\r\n", &saveptr); ptr;
                 ptr = strtok_r(NULL, " \t\r\n", &saveptr)) {
                errno = 0;
                id = strtol(ptr, &endptr, 0);
                if (errno == ERANGE || !endptr || *endptr) {
                    gf_log(this->name, GF_LOG_ERROR, "failed to parse %s",
                           filename);
                    break;
                }
                if (idx < call_stack_groups_capacity(frame->root))
                    frame->root->groups[idx] = id;
                idx++;
                if (idx == GF_MAX_AUX_GROUPS)
                    break;
            }
            if (idx > call_stack_groups_capacity(frame->root)) {
                ngroups = idx;
                rewind(fp);
            } else {
                frame->root->ngrps = idx;
                break;
            }
        }
    out:
        if (fp)
            fclose(fp);
    }
#elif defined(GF_SOLARIS_HOST_OS)
    char filename[32];
    char scratch[128];
    prcred_t *prcred = (prcred_t *)scratch;
    FILE *fp = NULL;
    int ret = 0;
    int ngrps;

    ret = snprintf(filename, sizeof filename, "/proc/%d/cred",
                   frame->root->pid);

    if (ret < sizeof filename) {
        fp = fopen(filename, "r");
        if (fp != NULL) {
            if (fgets(scratch, sizeof scratch, fp) != NULL) {
                ngrps = MIN(prcred->pr_ngroups, GF_MAX_AUX_GROUPS);
                if (call_stack_alloc_groups(frame->root, ngrps) != 0) {
                    fclose(fp);
                    return;
                }
            }
            fclose(fp);
        }
    }
#elif defined(CTL_KERN) /* DARWIN and *BSD */
    /*
       N.B. CTL_KERN is an enum on Linux. (Meaning, if it's not
       obvious, that it's not subject to preprocessor directives
       like '#if defined'.)
       Unlike Linux, on Mac OS and the BSDs it is a #define. We
       could test to see that KERN_PROC is defined, but, barring any
       evidence to the contrary, I think that's overkill.
       We might also test that GF_DARWIN_HOST_OS is defined, why
       limit this to just Mac OS. It's equally valid for the BSDs
       and we do have people building on NetBSD and FreeBSD.
    */
    int name[] = {CTL_KERN, KERN_PROC, KERN_PROC_PID, frame->root->pid};
    size_t namelen = sizeof name / sizeof name[0];
    struct kinfo_proc kp;
    size_t kplen = sizeof(kp);
    int i, ngroups;

    if (sysctl(name, namelen, &kp, &kplen, NULL, 0) != 0)
        return;
    ngroups = MIN(kp.kp_eproc.e_ucred.cr_ngroups, NGROUPS_MAX);
    if (call_stack_alloc_groups(frame->root, ngroups) != 0)
        return;
    for (i = 0; i < ngroups; i++)
        frame->root->groups[i] = kp.kp_eproc.e_ucred.cr_groups[i];
    frame->root->ngrps = ngroups;
#else
    frame->root->ngrps = 0;
#endif /* GF_LINUX_HOST_OS */
}

/*
 * Get the groups for the PID associated with this frame. If enabled,
 * use the gid cache to reduce group list collection.
 */
static void
get_groups(fuse_private_t *priv, call_frame_t *frame)
{
    int i;
    const gid_list_t *gl;
    gid_list_t agl;

    if (!priv || !priv->gid_cache_timeout) {
        frame_fill_groups(frame);
        return;
    }

    if (-1 == priv->gid_cache_timeout) {
        frame->root->ngrps = 0;
        return;
    }

    gl = gid_cache_lookup(&priv->gid_cache, frame->root->pid, frame->root->uid,
                          frame->root->gid);
    if (gl) {
        if (call_stack_alloc_groups(frame->root, gl->gl_count) != 0) {
            gid_cache_release(&priv->gid_cache, gl);
            return;
        }
        frame->root->ngrps = gl->gl_count;
        for (i = 0; i < gl->gl_count; i++)
            frame->root->groups[i] = gl->gl_list[i];
        gid_cache_release(&priv->gid_cache, gl);
        return;
    }

    frame_fill_groups(frame);

    agl.gl_id = frame->root->pid;
    agl.gl_uid = frame->root->uid;
    agl.gl_gid = frame->root->gid;
    agl.gl_count = frame->root->ngrps;
    agl.gl_list = GF_CALLOC(frame->root->ngrps, sizeof(gid_t),
                            gf_fuse_mt_gids_t);
    if (!agl.gl_list)
        return;

    for (i = 0; i < frame->root->ngrps; i++)
        agl.gl_list[i] = frame->root->groups[i];

    if (gid_cache_add(&priv->gid_cache, &agl) != 1)
        GF_FREE(agl.gl_list);
}

call_frame_t *
get_call_frame_for_req(fuse_state_t *state)
{
    call_pool_t *pool = NULL;
    fuse_in_header_t *finh = NULL;
    call_frame_t *frame = NULL;
    xlator_t *this = NULL;
    fuse_private_t *priv = NULL;

    pool = state->pool;
    finh = state->finh;
    this = state->this;
    priv = this->private;

    frame = create_frame(this, pool);
    if (!frame)
        return NULL;

    if (finh) {
        frame->root->uid = finh->uid;
        frame->root->gid = finh->gid;
        frame->root->pid = finh->pid;
        set_lk_owner_from_uint64(&frame->root->lk_owner, state->lk_owner);
    }

    get_groups(priv, frame);

    if (priv && priv->client_pid_set)
        frame->root->pid = priv->client_pid;

    frame->root->type = GF_OP_TYPE_FOP;

    return frame;
}

inode_t *
fuse_ino_to_inode(uint64_t ino, xlator_t *fuse)
{
    inode_t *inode = NULL;
    xlator_t *active_subvol = NULL;

    if (ino == 1) {
        active_subvol = fuse_active_subvol(fuse);
        if (active_subvol)
            inode = active_subvol->itable->root;
    } else {
        inode = (inode_t *)(unsigned long)ino;
        inode_ref(inode);
    }

    return inode;
}

uint64_t
inode_to_fuse_nodeid(inode_t *inode)
{
    if (!inode)
        return 0;
    if (__is_root_gfid(inode->gfid))
        return 1;

    return (unsigned long)inode;
}

GF_MUST_CHECK int32_t
fuse_loc_fill(loc_t *loc, fuse_state_t *state, ino_t ino, ino_t par,
              const char *name)
{
    inode_t *inode = NULL;
    inode_t *parent = NULL;
    int32_t ret = -1;
    char *path = NULL;
    uuid_t null_gfid = {
        0,
    };

    /* resistance against multiple invocation of loc_fill not to get
       reference leaks via inode_search() */

    if (name) {
        parent = loc->parent;
        if (!parent) {
            parent = fuse_ino_to_inode(par, state->this);
            loc->parent = parent;
            if (parent)
                gf_uuid_copy(loc->pargfid, parent->gfid);
        }

        inode = loc->inode;
        if (!inode && parent) {
            inode = inode_grep(parent->table, parent, name);
            loc->inode = inode;
        }

        ret = inode_path(parent, name, &path);
        if (ret <= 0) {
            gf_log("glusterfs-fuse", GF_LOG_DEBUG,
                   "inode_path failed for %s/%s",
                   (parent) ? uuid_utoa(parent->gfid) : "0", name);
            goto fail;
        }
        loc->path = path;
    } else {
        inode = loc->inode;
        if (!inode) {
            inode = fuse_ino_to_inode(ino, state->this);
            loc->inode = inode;
            if (inode)
                gf_uuid_copy(loc->gfid, inode->gfid);
        }

        parent = loc->parent;
        if (!parent) {
            parent = inode_parent(inode, null_gfid, NULL);
            loc->parent = parent;
            if (parent)
                gf_uuid_copy(loc->pargfid, parent->gfid);
        }

        ret = inode_path(inode, NULL, &path);
        if (ret <= 0) {
            gf_log("glusterfs-fuse", GF_LOG_DEBUG, "inode_path failed for %s",
                   (inode) ? uuid_utoa(inode->gfid) : "0");
            goto fail;
        }
        loc->path = path;
    }

    if (loc->path) {
        loc->name = strrchr(loc->path, '/');
        if (loc->name)
            loc->name++;
        else
            loc->name = "";
    }

    if ((ino != 1) && (parent == NULL)) {
        gf_log("fuse-bridge", GF_LOG_DEBUG,
               "failed to search parent for %" PRId64 "/%s (%" PRId64 ")",
               (ino_t)par, name, (ino_t)ino);
        ret = -1;
        goto fail;
    }
    ret = 0;
fail:
    /* this should not happen as inode_path returns -1 when buf is NULL
       for sure */
    if (path && !loc->path)
        GF_FREE(path);
    return ret;
}

/* courtesy of folly */
void
gf_fuse_stat2attr(struct iatt *st, struct fuse_attr *fa,
                  gf_boolean_t enable_ino32)
{
    if (enable_ino32)
        fa->ino = GF_FUSE_SQUASH_INO(st->ia_ino);
    else
        fa->ino = st->ia_ino;

    fa->size = st->ia_size;
    fa->blocks = st->ia_blocks;
    fa->atime = st->ia_atime;
    fa->mtime = st->ia_mtime;
    fa->ctime = st->ia_ctime;
    fa->atimensec = st->ia_atime_nsec;
    fa->mtimensec = st->ia_mtime_nsec;
    fa->ctimensec = st->ia_ctime_nsec;
    fa->mode = st_mode_from_ia(st->ia_prot, st->ia_type);
    fa->nlink = st->ia_nlink;
    fa->uid = st->ia_uid;
    fa->gid = st->ia_gid;
    fa->rdev = makedev(ia_major(st->ia_rdev), ia_minor(st->ia_rdev));
#if FUSE_KERNEL_MINOR_VERSION >= 9
    fa->blksize = st->ia_blksize;
#endif
#ifdef GF_DARWIN_HOST_OS
    fa->crtime = (uint64_t)-1;
    fa->crtimensec = (uint32_t)-1;
    fa->flags = 0;
#endif
}

void
gf_fuse_fill_dirent(gf_dirent_t *entry, struct fuse_dirent *fde,
                    gf_boolean_t enable_ino32)
{
    if (enable_ino32)
        fde->ino = GF_FUSE_SQUASH_INO(entry->d_ino);
    else
        fde->ino = entry->d_ino;

    fde->off = entry->d_off;
    fde->type = entry->d_type;
    fde->namelen = strlen(entry->d_name);
    (void)memcpy(fde->name, entry->d_name, fde->namelen);
}

static int
fuse_do_flip_xattr_ns(char *okey, const char *nns, char **nkey)
{
    int ret = 0;
    char *key = NULL;

    okey = strchr(okey, '.');
    GF_ASSERT(okey);

    int key_len = strlen(nns) + strlen(okey);
    key = GF_MALLOC(key_len + 1, gf_common_mt_char);
    if (!key) {
        ret = -1;
        goto out;
    }

    strcpy(key, nns);
    strcat(key, okey);

    *nkey = key;

out:
    return ret;
}

static int
fuse_xattr_alloc_default(char *okey, char **nkey)
{
    int ret = 0;

    *nkey = gf_strdup(okey);
    if (!*nkey)
        ret = -1;
    return ret;
}

#define PRIV_XA_NS "trusted"
#define UNPRIV_XA_NS "system"

int
fuse_flip_xattr_ns(fuse_private_t *priv, char *okey, char **nkey)
{
    int ret = 0;
    gf_boolean_t need_flip = _gf_false;

    if (GF_CLIENT_PID_GSYNCD == priv->client_pid) {
        /* valid xattr(s): *xtime, volume-mark* */
        gf_log("glusterfs-fuse", GF_LOG_DEBUG,
               "PID: %d, checking xattr(s): "
               "volume-mark*, *xtime",
               priv->client_pid);
        if ((strcmp(okey, UNPRIV_XA_NS ".glusterfs.volume-mark") == 0) ||
            (fnmatch(UNPRIV_XA_NS ".glusterfs.volume-mark.*", okey,
                     FNM_PERIOD) == 0) ||
            (fnmatch(UNPRIV_XA_NS ".glusterfs.*.xtime", okey, FNM_PERIOD) == 0))
            need_flip = _gf_true;
    }

    if (need_flip) {
        gf_log("glusterfs-fuse", GF_LOG_DEBUG,
               "flipping %s to " PRIV_XA_NS " equivalent", okey);
        ret = fuse_do_flip_xattr_ns(okey, PRIV_XA_NS, nkey);
    } else {
        /* if we cannot match, continue with what we got */
        ret = fuse_xattr_alloc_default(okey, nkey);
    }

    return ret;
}

int
fuse_ignore_xattr_set(fuse_private_t *priv, char *key)
{
    int ret = 0;

    /* don't mess with user namespace */
    if (fnmatch("user.*", key, FNM_PERIOD) == 0)
        goto out;

    if (priv->client_pid != GF_CLIENT_PID_GSYNCD)
        goto out;

    /* trusted NS check */
    if (!((fnmatch("*.glusterfs.*.xtime", key, FNM_PERIOD) == 0) ||
          (fnmatch("*.glusterfs.volume-mark", key, FNM_PERIOD) == 0) ||
          (fnmatch("*.glusterfs.volume-mark.*", key, FNM_PERIOD) == 0) ||
          (fnmatch("system.posix_acl_access", key, FNM_PERIOD) == 0) ||
          (fnmatch("glusterfs.gfid.newfile", key, FNM_PERIOD) == 0) ||
          (fnmatch("*.glusterfs.shard.block-size", key, FNM_PERIOD) == 0) ||
          (fnmatch("*.glusterfs.shard.file-size", key, FNM_PERIOD) == 0)))
        ret = -1;

out:
    gf_log("glusterfs-fuse", GF_LOG_DEBUG,
           "%s setxattr: key [%s], "
           " client pid [%d]",
           (ret ? "disallowing" : "allowing"), key, priv->client_pid);

    return ret;
}

int
fuse_check_selinux_cap_xattr(fuse_private_t *priv, char *name)
{
    int ret = -1;

    if (strcmp(name, "security.selinux") &&
        strcmp(name, "security.capability")) {
        /* if xattr name is not of interest, no validations needed */
        ret = 0;
        goto out;
    }

    if ((strcmp(name, "security.selinux") == 0) && (priv->selinux)) {
        ret = 0;
    }

    if ((strcmp(name, "security.capability") == 0) &&
        ((priv->capability) || (priv->selinux))) {
        ret = 0;
    }

out:
    return ret;
}