diff options
| author |   Jan Engelhardt <jengelh@medozas.de> | 2009-06-17 22:14:54 +0200 |
|---|---|---|
| committer | Jan Engelhardt <jengelh@medozas.de> | 2010-02-10 17:50:47 +0100 |
| commit | e3eaa9910b380530cfd2c0670fcd3f627674da8a (patch) | |
| tree | 309e522e78f78149ec3cb99ffc386d1b72415a96 /net/netfilter/xt_repldata.h | |
| parent | netfilter: xtables: use xt_table for hook instantiation (diff) | |
| download | linux-dev-e3eaa9910b380530cfd2c0670fcd3f627674da8a.tar.xz linux-dev-e3eaa9910b380530cfd2c0670fcd3f627674da8a.zip | |
netfilter: xtables: generate initial table on-demand
The static initial tables are pretty large, and after the net
namespace has been instantiated, they just hang around for nothing.
This commit removes them and creates tables on-demand at runtime when
needed.
Size shrinks by 7735 bytes (x86_64).
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Diffstat (limited to 'net/netfilter/xt_repldata.h')
| -rw-r--r-- | net/netfilter/xt_repldata.h | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/net/netfilter/xt_repldata.h b/net/netfilter/xt_repldata.h new file mode 100644 index 000000000000..6efe4e5a81c6 --- /dev/null +++ b/net/netfilter/xt_repldata.h @@ -0,0 +1,35 @@ +/* + * Today's hack: quantum tunneling in structs + * + * 'entries' and 'term' are never anywhere referenced by word in code. In fact, + * they serve as the hanging-off data accessed through repl.data[]. + */ + +#define xt_alloc_initial_table(type, typ2) ({ \ + unsigned int hook_mask = info->valid_hooks; \ + unsigned int nhooks = hweight32(hook_mask); \ + unsigned int bytes = 0, hooknum = 0, i = 0; \ + struct { \ + struct type##_replace repl; \ + struct type##_standard entries[nhooks]; \ + struct type##_error term; \ + } *tbl = kzalloc(sizeof(*tbl), GFP_KERNEL); \ + if (tbl == NULL) \ + return NULL; \ + strncpy(tbl->repl.name, info->name, sizeof(tbl->repl.name)); \ + tbl->term = (struct type##_error)typ2##_ERROR_INIT; \ + tbl->repl.valid_hooks = hook_mask; \ + tbl->repl.num_entries = nhooks + 1; \ + tbl->repl.size = nhooks * sizeof(struct type##_standard) + \ + sizeof(struct type##_error); \ + for (; hook_mask != 0; hook_mask >>= 1, ++hooknum) { \ + if (!(hook_mask & 1)) \ + continue; \ + tbl->repl.hook_entry[hooknum] = bytes; \ + tbl->repl.underflow[hooknum] = bytes; \ + tbl->entries[i++] = (struct type##_standard) \ + typ2##_STANDARD_INIT(NF_ACCEPT); \ + bytes += sizeof(struct type##_standard); \ + } \ + tbl; \ +}) |