From: JP Abgrall <jpa@google.com>
Date: Wed, 31 Aug 2011 20:50:15 +0000 (-0700)
Subject: netfilter: qtaguid: fix proc/.../stats uid filtered output
X-Git-Tag: firefly_0821_release~7613^2~328
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=64753a4df63a211c52a40e4cdf6632e73f2a235d;p=firefly-linux-kernel-4.4.55.git
netfilter: qtaguid: fix proc/.../stats uid filtered output
"cat /proc/net/xt_qtaguid/stats"
for a non-priviledged UID would output multiple twice its own stats.
The fix tweaks the way lines are counted.
Non-root:
idx iface acct_tag_hex uid_tag_int cnt_set ...
2 wlan0 0x0 10022 0 ...
3 wlan0 0x0 10022 1 ...
4 wlan0 0x3010000000000000 10022 0 ...
5 wlan0 0x3010000000000000 10022 1 ...
Root:
idx iface acct_tag_hex uid_tag_int cnt_set
2 wlan0 0x0 0 0 ...
3 wlan0 0x0 0 1 ...
4 wlan0 0x0 1000 0 ...
...
12 wlan0 0x0 10022 0 ...
13 wlan0 0x0 10022 1 ...
...
18 wlan0 0x3010000000000000 10022 0 ...
19 wlan0 0x3010000000000000 10022 1 ...
Change-Id: I3cae1f4fee616bc897831350374656b0c718c45b
Signed-off-by: JP Abgrall <jpa@google.com>
---
diff --git a/net/netfilter/xt_qtaguid.c b/net/netfilter/xt_qtaguid.c
index 80b5990045bc..b145f5a4b45d 100644
--- a/net/netfilter/xt_qtaguid.c
+++ b/net/netfilter/xt_qtaguid.c
@@ -1788,6 +1788,7 @@ struct proc_print_info {
struct iface_stat *iface_entry;
struct tag_stat *ts_entry;
int item_index;
+ int items_to_skip;
int char_count;
};
@@ -1795,7 +1796,10 @@ static int pp_stats_line(struct proc_print_info *ppi, int cnt_set)
{
int len;
struct data_counters *cnts;
+
if (!ppi->item_index) {
+ if (ppi->item_index++ < ppi->items_to_skip)
+ return 0;
len = snprintf(ppi->outp, ppi->char_count,
"idx iface acct_tag_hex uid_tag_int cnt_set "
"rx_bytes rx_packets "
@@ -1809,6 +1813,7 @@ static int pp_stats_line(struct proc_print_info *ppi, int cnt_set)
} else {
tag_t tag = ppi->ts_entry->tn.tag;
uid_t stat_uid = get_uid_from_tag(tag);
+
if (!can_read_other_uid_stats(stat_uid)) {
CT_DEBUG("qtaguid: stats line: "
"%s 0x%llx %u: "
@@ -1818,6 +1823,8 @@ static int pp_stats_line(struct proc_print_info *ppi, int cnt_set)
current->pid, current_fsuid());
return 0;
}
+ if (ppi->item_index++ < ppi->items_to_skip)
+ return 0;
cnts = &ppi->ts_entry->counters;
len = snprintf(
ppi->outp, ppi->char_count,
@@ -1891,11 +1898,13 @@ static int qtaguid_stats_proc_read(char *page, char **num_items_returned,
ppi.item_index = 0;
ppi.char_count = char_count;
ppi.num_items_returned = num_items_returned;
+ ppi.items_to_skip = items_to_skip;
if (unlikely(module_passive)) {
len = pp_stats_line(&ppi, 0);
/* The header should always be shorter than the buffer. */
WARN_ON(len >= ppi.char_count);
+ (*num_items_returned)++;
*eof = 1;
return len;
}
@@ -1907,16 +1916,17 @@ static int qtaguid_stats_proc_read(char *page, char **num_items_returned,
if (*eof)
return 0;
- if (!items_to_skip) {
- /* The idx is there to help debug when things go belly up. */
- len = pp_stats_line(&ppi, 0);
- /* Don't advance the outp unless the whole line was printed */
- if (len >= ppi.char_count) {
- *ppi.outp = '\0';
- return ppi.outp - page;
- }
+ /* The idx is there to help debug when things go belly up. */
+ len = pp_stats_line(&ppi, 0);
+ /* Don't advance the outp unless the whole line was printed */
+ if (len >= ppi.char_count) {
+ *ppi.outp = '\0';
+ return ppi.outp - page;
+ }
+ if (len) {
ppi.outp += len;
ppi.char_count -= len;
+ (*num_items_returned)++;
}
spin_lock_bh(&iface_stat_list_lock);
@@ -1927,8 +1937,6 @@ static int qtaguid_stats_proc_read(char *page, char **num_items_returned,
node;
node = rb_next(node)) {
ppi.ts_entry = rb_entry(node, struct tag_stat, tn.node);
- if (ppi.item_index++ < items_to_skip)
- continue;
if (!pp_sets(&ppi)) {
spin_unlock_bh(
&ppi.iface_entry->tag_stat_list_lock);