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    Subject[PATCH 5/7][RFC] netfilter: xt_qtaguid: start tracking iface rx/tx at low level
    Date
    From: JP Abgrall <jpa@google.com>

    qtaguid tracks the device stats by monitoring when it goes up and down,
    then it gets the dev_stats().
    But devs don't correctly report stats (either they don't count headers
    symmetrically between rx/tx, or they count internal control messages).

    Now qtaguid counts the rx/tx bytes/packets during raw:prerouting and
    mangle:postrouting (nat is not available in ipv6).

    The results are in
    /proc/net/xt_qtaguid/iface_stat_fmt
    which outputs a format line (bash expansion):
    ifname total_skb_{rx,tx}_{bytes,packets}

    Added event counters for pre/post handling.
    Added extra ctrl_*() pid/uid debugging.

    Cc: netdev@vger.kernel.org
    Cc: JP Abgrall <jpa@google.com>
    Cc: Ashish Sharma <ashishsharma@google.com>
    Cc: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
    Signed-off-by: JP Abgrall <jpa@google.com>
    Signed-off-by: John Stultz <john.stultz@linaro.org>
    ---
    net/netfilter/xt_qtaguid.c | 277 +++++++++++++++++++++++++++--------
    net/netfilter/xt_qtaguid_internal.h | 5 +-
    net/netfilter/xt_qtaguid_print.c | 18 ++-
    3 files changed, 233 insertions(+), 67 deletions(-)

    diff --git a/net/netfilter/xt_qtaguid.c b/net/netfilter/xt_qtaguid.c
    index 47dfb9e..f490ef5 100644
    --- a/net/netfilter/xt_qtaguid.c
    +++ b/net/netfilter/xt_qtaguid.c
    @@ -104,8 +104,15 @@ module_param_named(debug_mask, qtaguid_debug_mask, uint, S_IRUGO | S_IWUSR);
    /*---------------------------------------------------------------------------*/
    static const char *iface_stat_procdirname = "iface_stat";
    static struct proc_dir_entry *iface_stat_procdir;
    +/*
    + * The iface_stat_all* will go away once userspace gets use to the new fields
    + * that have a format line.
    + */
    static const char *iface_stat_all_procfilename = "iface_stat_all";
    static struct proc_dir_entry *iface_stat_all_procfile;
    +static const char *iface_stat_fmt_procfilename = "iface_stat_fmt";
    +static struct proc_dir_entry *iface_stat_fmt_procfile;
    +

    /*
    * Ordering of locks:
    @@ -118,9 +125,9 @@ static struct proc_dir_entry *iface_stat_all_procfile;
    * Notice how sock_tag_list_lock is held sometimes when uid_tag_data_tree_lock
    * is acquired.
    *
    - * Call tree with all lock holders as of 2011-09-25:
    + * Call tree with all lock holders as of 2012-04-27:
    *
    - * iface_stat_all_proc_read()
    + * iface_stat_fmt_proc_read()
    * iface_stat_list_lock
    * (struct iface_stat)
    *
    @@ -771,13 +778,14 @@ done:
    return iface_entry;
    }

    -static int iface_stat_all_proc_read(char *page, char **num_items_returned,
    +static int iface_stat_fmt_proc_read(char *page, char **num_items_returned,
    off_t items_to_skip, int char_count,
    int *eof, void *data)
    {
    char *outp = page;
    int item_index = 0;
    int len;
    + int fmt = (int)data; /* The data is just 1 (old) or 2 (uses fmt) */
    struct iface_stat *iface_entry;
    struct rtnl_link_stats64 dev_stats, *stats;
    struct rtnl_link_stats64 no_dev_stats = {0};
    @@ -787,14 +795,32 @@ static int iface_stat_all_proc_read(char *page, char **num_items_returned,
    return 0;
    }

    - CT_DEBUG("qtaguid:proc iface_stat_all "
    + CT_DEBUG("qtaguid:proc iface_stat_fmt "
    + "pid=%u tgid=%u uid=%u "
    "page=%p *num_items_returned=%p off=%ld "
    - "char_count=%d *eof=%d\n", page, *num_items_returned,
    + "char_count=%d *eof=%d\n",
    + current->pid, current->tgid, current_fsuid(),
    + page, *num_items_returned,
    items_to_skip, char_count, *eof);

    if (*eof)
    return 0;

    + if (fmt == 2 && item_index++ >= items_to_skip) {
    + len = snprintf(outp, char_count,
    + "ifname "
    + "total_skb_rx_bytes total_skb_rx_packets "
    + "total_skb_tx_bytes total_skb_tx_packets\n"
    + );
    + if (len >= char_count) {
    + *outp = '\0';
    + return outp - page;
    + }
    + outp += len;
    + char_count -= len;
    + (*num_items_returned)++;
    + }
    +
    /*
    * This lock will prevent iface_stat_update() from changing active,
    * and in turn prevent an interface from unregistering itself.
    @@ -810,18 +836,37 @@ static int iface_stat_all_proc_read(char *page, char **num_items_returned,
    } else {
    stats = &no_dev_stats;
    }
    - len = snprintf(outp, char_count,
    - "%s %d "
    - "%llu %llu %llu %llu "
    - "%llu %llu %llu %llu\n",
    - iface_entry->ifname,
    - iface_entry->active,
    - iface_entry->totals[IFS_RX].bytes,
    - iface_entry->totals[IFS_RX].packets,
    - iface_entry->totals[IFS_TX].bytes,
    - iface_entry->totals[IFS_TX].packets,
    - stats->rx_bytes, stats->rx_packets,
    - stats->tx_bytes, stats->tx_packets);
    + /*
    + * If the meaning of the data changes, then update the fmtX
    + * string.
    + */
    + if (fmt == 1) {
    + len = snprintf(
    + outp, char_count,
    + "%s %d "
    + "%llu %llu %llu %llu "
    + "%llu %llu %llu %llu\n",
    + iface_entry->ifname,
    + iface_entry->active,
    + iface_entry->totals_via_dev[IFS_RX].bytes,
    + iface_entry->totals_via_dev[IFS_RX].packets,
    + iface_entry->totals_via_dev[IFS_TX].bytes,
    + iface_entry->totals_via_dev[IFS_TX].packets,
    + stats->rx_bytes, stats->rx_packets,
    + stats->tx_bytes, stats->tx_packets
    + );
    + } else {
    + len = snprintf(
    + outp, char_count,
    + "%s "
    + "%llu %llu %llu %llu\n",
    + iface_entry->ifname,
    + iface_entry->totals_via_skb[IFS_RX].bytes,
    + iface_entry->totals_via_skb[IFS_RX].packets,
    + iface_entry->totals_via_skb[IFS_TX].bytes,
    + iface_entry->totals_via_skb[IFS_TX].packets
    + );
    + }
    if (len >= char_count) {
    spin_unlock_bh(&iface_stat_list_lock);
    *outp = '\0';
    @@ -855,13 +900,17 @@ static void iface_create_proc_worker(struct work_struct *work)
    new_iface->proc_ptr = proc_entry;

    create_proc_read_entry("tx_bytes", proc_iface_perms, proc_entry,
    - read_proc_u64, &new_iface->totals[IFS_TX].bytes);
    + read_proc_u64,
    + &new_iface->totals_via_dev[IFS_TX].bytes);
    create_proc_read_entry("rx_bytes", proc_iface_perms, proc_entry,
    - read_proc_u64, &new_iface->totals[IFS_RX].bytes);
    + read_proc_u64,
    + &new_iface->totals_via_dev[IFS_RX].bytes);
    create_proc_read_entry("tx_packets", proc_iface_perms, proc_entry,
    - read_proc_u64, &new_iface->totals[IFS_TX].packets);
    + read_proc_u64,
    + &new_iface->totals_via_dev[IFS_TX].packets);
    create_proc_read_entry("rx_packets", proc_iface_perms, proc_entry,
    - read_proc_u64, &new_iface->totals[IFS_RX].packets);
    + read_proc_u64,
    + &new_iface->totals_via_dev[IFS_RX].packets);
    create_proc_read_entry("active", proc_iface_perms, proc_entry,
    read_proc_bool, &new_iface->active);

    @@ -965,11 +1014,13 @@ static void iface_check_stats_reset_and_adjust(struct net_device *net_dev,
    "iface reset its stats unexpectedly\n", __func__,
    net_dev->name);

    - iface->totals[IFS_TX].bytes += iface->last_known[IFS_TX].bytes;
    - iface->totals[IFS_TX].packets +=
    + iface->totals_via_dev[IFS_TX].bytes +=
    + iface->last_known[IFS_TX].bytes;
    + iface->totals_via_dev[IFS_TX].packets +=
    iface->last_known[IFS_TX].packets;
    - iface->totals[IFS_RX].bytes += iface->last_known[IFS_RX].bytes;
    - iface->totals[IFS_RX].packets +=
    + iface->totals_via_dev[IFS_RX].bytes +=
    + iface->last_known[IFS_RX].bytes;
    + iface->totals_via_dev[IFS_RX].packets +=
    iface->last_known[IFS_RX].packets;
    iface->last_known_valid = false;
    IF_DEBUG("qtaguid: %s(%s): iface=%p "
    @@ -1137,6 +1188,27 @@ static struct sock_tag *get_sock_stat(const struct sock *sk)
    return sock_tag_entry;
    }

    +static int ipx_proto(const struct sk_buff *skb,
    + struct xt_action_param *par)
    +{
    + int thoff, tproto;
    +
    + switch (par->family) {
    + case NFPROTO_IPV6:
    + tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
    + if (tproto < 0)
    + MT_DEBUG("%s(): transport header not found in ipv6"
    + " skb=%p\n", __func__, skb);
    + break;
    + case NFPROTO_IPV4:
    + tproto = ip_hdr(skb)->protocol;
    + break;
    + default:
    + tproto = IPPROTO_RAW;
    + }
    + return tproto;
    +}
    +
    static void
    data_counters_update(struct data_counters *dc, int set,
    enum ifs_tx_rx direction, int proto, int bytes)
    @@ -1197,10 +1269,10 @@ static void iface_stat_update(struct net_device *net_dev, bool stash_only)
    spin_unlock_bh(&iface_stat_list_lock);
    return;
    }
    - entry->totals[IFS_TX].bytes += stats->tx_bytes;
    - entry->totals[IFS_TX].packets += stats->tx_packets;
    - entry->totals[IFS_RX].bytes += stats->rx_bytes;
    - entry->totals[IFS_RX].packets += stats->rx_packets;
    + entry->totals_via_dev[IFS_TX].bytes += stats->tx_bytes;
    + entry->totals_via_dev[IFS_TX].packets += stats->tx_packets;
    + entry->totals_via_dev[IFS_RX].bytes += stats->rx_bytes;
    + entry->totals_via_dev[IFS_RX].packets += stats->rx_packets;
    /* We don't need the last_known[] anymore */
    entry->last_known_valid = false;
    _iface_stat_set_active(entry, net_dev, false);
    @@ -1210,6 +1282,67 @@ static void iface_stat_update(struct net_device *net_dev, bool stash_only)
    spin_unlock_bh(&iface_stat_list_lock);
    }

    +/*
    + * Update stats for the specified interface from the skb.
    + * Do nothing if the entry
    + * does not exist (when a device was never configured with an IP address).
    + * Called on each sk.
    + */
    +static void iface_stat_update_from_skb(const struct sk_buff *skb,
    + struct xt_action_param *par)
    +{
    + struct iface_stat *entry;
    + const struct net_device *el_dev;
    + enum ifs_tx_rx direction = par->in ? IFS_RX : IFS_TX;
    + int bytes = skb->len;
    +
    + if (!skb->dev) {
    + MT_DEBUG("qtaguid[%d]: no skb->dev\n", par->hooknum);
    + el_dev = par->in ? : par->out;
    + } else {
    + const struct net_device *other_dev;
    + el_dev = skb->dev;
    + other_dev = par->in ? : par->out;
    + if (el_dev != other_dev) {
    + MT_DEBUG("qtaguid[%d]: skb->dev=%p %s vs "
    + "par->(in/out)=%p %s\n",
    + par->hooknum, el_dev, el_dev->name, other_dev,
    + other_dev->name);
    + }
    + }
    +
    + if (unlikely(!el_dev)) {
    + pr_err("qtaguid[%d]: %s(): no par->in/out?!!\n",
    + par->hooknum, __func__);
    + BUG();
    + } else if (unlikely(!el_dev->name)) {
    + pr_err("qtaguid[%d]: %s(): no dev->name?!!\n",
    + par->hooknum, __func__);
    + BUG();
    + } else {
    + int proto = ipx_proto(skb, par);
    + MT_DEBUG("qtaguid[%d]: dev name=%s type=%d fam=%d proto=%d\n",
    + par->hooknum, el_dev->name, el_dev->type,
    + par->family, proto);
    + }
    +
    + spin_lock_bh(&iface_stat_list_lock);
    + entry = get_iface_entry(el_dev->name);
    + if (entry == NULL) {
    + IF_DEBUG("qtaguid: iface_stat: %s(%s): not tracked\n",
    + __func__, el_dev->name);
    + spin_unlock_bh(&iface_stat_list_lock);
    + return;
    + }
    +
    + IF_DEBUG("qtaguid: %s(%s): entry=%p\n", __func__,
    + el_dev->name, entry);
    +
    + entry->totals_via_skb[direction].bytes += bytes;
    + entry->totals_via_skb[direction].packets++;
    + spin_unlock_bh(&iface_stat_list_lock);
    +}
    +
    static void tag_stat_update(struct tag_stat *tag_entry,
    enum ifs_tx_rx direction, int proto, int bytes)
    {
    @@ -1457,18 +1590,31 @@ static int __init iface_stat_init(struct proc_dir_entry *parent_procdir)
    parent_procdir);
    if (!iface_stat_all_procfile) {
    pr_err("qtaguid: iface_stat: init "
    - " failed to create stat_all proc entry\n");
    + " failed to create stat_old proc entry\n");
    err = -1;
    goto err_zap_entry;
    }
    - iface_stat_all_procfile->read_proc = iface_stat_all_proc_read;
    + iface_stat_all_procfile->read_proc = iface_stat_fmt_proc_read;
    + iface_stat_all_procfile->data = (void *)1; /* fmt1 */
    +
    + iface_stat_fmt_procfile = create_proc_entry(iface_stat_fmt_procfilename,
    + proc_iface_perms,
    + parent_procdir);
    + if (!iface_stat_fmt_procfile) {
    + pr_err("qtaguid: iface_stat: init "
    + " failed to create stat_all proc entry\n");
    + err = -1;
    + goto err_zap_all_stats_entry;
    + }
    + iface_stat_fmt_procfile->read_proc = iface_stat_fmt_proc_read;
    + iface_stat_fmt_procfile->data = (void *)2; /* fmt2 */


    err = register_netdevice_notifier(&iface_netdev_notifier_blk);
    if (err) {
    pr_err("qtaguid: iface_stat: init "
    "failed to register dev event handler\n");
    - goto err_zap_all_stats_entry;
    + goto err_zap_all_stats_entries;
    }
    err = register_inetaddr_notifier(&iface_inetaddr_notifier_blk);
    if (err) {
    @@ -1489,6 +1635,8 @@ err_unreg_ip4_addr:
    unregister_inetaddr_notifier(&iface_inetaddr_notifier_blk);
    err_unreg_nd:
    unregister_netdevice_notifier(&iface_netdev_notifier_blk);
    +err_zap_all_stats_entries:
    + remove_proc_entry(iface_stat_fmt_procfilename, parent_procdir);
    err_zap_all_stats_entry:
    remove_proc_entry(iface_stat_all_procfilename, parent_procdir);
    err_zap_entry:
    @@ -1540,27 +1688,6 @@ static struct sock *qtaguid_find_sk(const struct sk_buff *skb,
    return sk;
    }

    -static int ipx_proto(const struct sk_buff *skb,
    - struct xt_action_param *par)
    -{
    - int thoff, tproto;
    -
    - switch (par->family) {
    - case NFPROTO_IPV6:
    - tproto = ipv6_find_hdr(skb, &thoff, -1, NULL, NULL);
    - if (tproto < 0)
    - MT_DEBUG("%s(): transport header not found in ipv6"
    - " skb=%p\n", __func__, skb);
    - break;
    - case NFPROTO_IPV4:
    - tproto = ip_hdr(skb)->protocol;
    - break;
    - default:
    - tproto = IPPROTO_RAW;
    - }
    - return tproto;
    -}
    -
    static void account_for_uid(const struct sk_buff *skb,
    const struct sock *alternate_sk, uid_t uid,
    struct xt_action_param *par)
    @@ -1620,8 +1747,22 @@ static bool qtaguid_mt(const struct sk_buff *skb, struct xt_action_param *par)
    goto ret_res;
    }

    - sk = skb->sk;
    + switch (par->hooknum) {
    + case NF_INET_PRE_ROUTING:
    + case NF_INET_POST_ROUTING:
    + atomic64_inc(&qtu_events.match_calls_prepost);
    + iface_stat_update_from_skb(skb, par);
    + /*
    + * We are done in pre/post. The skb will get processed
    + * further alter.
    + */
    + res = (info->match ^ info->invert);
    + goto ret_res;
    + break;
    + /* default: Fall through and do UID releated work */
    + }

    + sk = skb->sk;
    if (sk == NULL) {
    /*
    * A missing sk->sk_socket happens when packets are in-flight
    @@ -1796,8 +1937,10 @@ static int qtaguid_ctrl_proc_read(char *page, char **num_items_returned,
    if (*eof)
    return 0;

    - CT_DEBUG("qtaguid: proc ctrl page=%p off=%ld char_count=%d *eof=%d\n",
    - page, items_to_skip, char_count, *eof);
    + CT_DEBUG("qtaguid: proc ctrl pid=%u tgid=%u uid=%u "
    + "page=%p off=%ld char_count=%d *eof=%d\n",
    + current->pid, current->tgid, current_fsuid(),
    + page, items_to_skip, char_count, *eof);

    spin_lock_bh(&sock_tag_list_lock);
    for (node = rb_first(&sock_tag_tree);
    @@ -1841,6 +1984,7 @@ static int qtaguid_ctrl_proc_read(char *page, char **num_items_returned,
    "delete_cmds=%llu "
    "iface_events=%llu "
    "match_calls=%llu "
    + "match_calls_prepost=%llu "
    "match_found_sk=%llu "
    "match_found_sk_in_ct=%llu "
    "match_found_no_sk_in_ct=%llu "
    @@ -1852,6 +1996,7 @@ static int qtaguid_ctrl_proc_read(char *page, char **num_items_returned,
    atomic64_read(&qtu_events.delete_cmds),
    atomic64_read(&qtu_events.iface_events),
    atomic64_read(&qtu_events.match_calls),
    + atomic64_read(&qtu_events.match_calls_prepost),
    atomic64_read(&qtu_events.match_found_sk),
    atomic64_read(&qtu_events.match_found_sk_in_ct),
    atomic64_read(
    @@ -2125,7 +2270,9 @@ static int ctrl_cmd_tag(const char *input)
    el_socket = sockfd_lookup(sock_fd, &res); /* This locks the file */
    if (!el_socket) {
    pr_info("qtaguid: ctrl_tag(%s): failed to lookup"
    - " sock_fd=%d err=%d\n", input, sock_fd, res);
    + " sock_fd=%d err=%d pid=%u tgid=%u uid=%u\n",
    + input, sock_fd, res, current->pid, current->tgid,
    + current_fsuid());
    goto err;
    }
    CT_DEBUG("qtaguid: ctrl_tag(%s): socket->...->f_count=%ld ->sk=%p\n",
    @@ -2270,7 +2417,9 @@ static int ctrl_cmd_untag(const char *input)
    el_socket = sockfd_lookup(sock_fd, &res); /* This locks the file */
    if (!el_socket) {
    pr_info("qtaguid: ctrl_untag(%s): failed to lookup"
    - " sock_fd=%d err=%d\n", input, sock_fd, res);
    + " sock_fd=%d err=%d pid=%u tgid=%u uid=%u\n",
    + input, sock_fd, res, current->pid, current->tgid,
    + current_fsuid());
    goto err;
    }
    CT_DEBUG("qtaguid: ctrl_untag(%s): socket->...->f_count=%ld ->sk=%p\n",
    @@ -2346,6 +2495,9 @@ static int qtaguid_ctrl_parse(const char *input, int count)
    char cmd;
    int res;

    + CT_DEBUG("qtaguid: ctrl(%s): pid=%u tgid=%u uid=%u\n",
    + input, current->pid, current->tgid, current_fsuid());
    +
    cmd = input[0];
    /* Collect params for commands */
    switch (cmd) {
    @@ -2522,9 +2674,12 @@ static int qtaguid_stats_proc_read(char *page, char **num_items_returned,
    return len;
    }

    - CT_DEBUG("qtaguid:proc stats page=%p *num_items_returned=%p off=%ld "
    - "char_count=%d *eof=%d\n", page, *num_items_returned,
    - items_to_skip, char_count, *eof);
    + CT_DEBUG("qtaguid:proc stats pid=%u tgid=%u uid=%u "
    + "page=%p *num_items_returned=%p off=%ld "
    + "char_count=%d *eof=%d\n",
    + current->pid, current->tgid, current_fsuid(),
    + page, *num_items_returned,
    + items_to_skip, char_count, *eof);

    if (*eof)
    return 0;
    diff --git a/net/netfilter/xt_qtaguid_internal.h b/net/netfilter/xt_qtaguid_internal.h
    index 02479d6..d79f838 100644
    --- a/net/netfilter/xt_qtaguid_internal.h
    +++ b/net/netfilter/xt_qtaguid_internal.h
    @@ -202,7 +202,8 @@ struct iface_stat {
    /* net_dev is only valid for active iface_stat */
    struct net_device *net_dev;

    - struct byte_packet_counters totals[IFS_MAX_DIRECTIONS];
    + struct byte_packet_counters totals_via_dev[IFS_MAX_DIRECTIONS];
    + struct byte_packet_counters totals_via_skb[IFS_MAX_DIRECTIONS];
    /*
    * We keep the last_known, because some devices reset their counters
    * just before NETDEV_UP, while some will reset just before
    @@ -254,6 +255,8 @@ struct qtaguid_event_counts {
    atomic64_t iface_events; /* Number of NETDEV_* events handled */

    atomic64_t match_calls; /* Number of times iptables called mt */
    + /* Number of times iptables called mt from pre or post routing hooks */
    + atomic64_t match_calls_prepost;
    /*
    * match_found_sk_*: numbers related to the netfilter matching
    * function finding a sock for the sk_buff.
    diff --git a/net/netfilter/xt_qtaguid_print.c b/net/netfilter/xt_qtaguid_print.c
    index 3917678..8cbd8e4 100644
    --- a/net/netfilter/xt_qtaguid_print.c
    +++ b/net/netfilter/xt_qtaguid_print.c
    @@ -183,7 +183,11 @@ char *pp_iface_stat(struct iface_stat *is)
    res = kasprintf(GFP_ATOMIC, "iface_stat@%p{"
    "list=list_head{...}, "
    "ifname=%s, "
    - "total={rx={bytes=%llu, "
    + "total_dev={rx={bytes=%llu, "
    + "packets=%llu}, "
    + "tx={bytes=%llu, "
    + "packets=%llu}}, "
    + "total_skb={rx={bytes=%llu, "
    "packets=%llu}, "
    "tx={bytes=%llu, "
    "packets=%llu}}, "
    @@ -198,10 +202,14 @@ char *pp_iface_stat(struct iface_stat *is)
    "tag_stat_tree=rb_root{...}}",
    is,
    is->ifname,
    - is->totals[IFS_RX].bytes,
    - is->totals[IFS_RX].packets,
    - is->totals[IFS_TX].bytes,
    - is->totals[IFS_TX].packets,
    + is->totals_via_dev[IFS_RX].bytes,
    + is->totals_via_dev[IFS_RX].packets,
    + is->totals_via_dev[IFS_TX].bytes,
    + is->totals_via_dev[IFS_TX].packets,
    + is->totals_via_skb[IFS_RX].bytes,
    + is->totals_via_skb[IFS_RX].packets,
    + is->totals_via_skb[IFS_TX].bytes,
    + is->totals_via_skb[IFS_TX].packets,
    is->last_known_valid,
    is->last_known[IFS_RX].bytes,
    is->last_known[IFS_RX].packets,
    --
    1.7.9.5


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      Last update: 2012-09-22 04:21    [W:0.060 / U:0.884 seconds]
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