Root/
1 | /* |
2 | * linux/net/sunrpc/socklib.c |
3 | * |
4 | * Common socket helper routines for RPC client and server |
5 | * |
6 | * Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> |
7 | */ |
8 | |
9 | #include <linux/compiler.h> |
10 | #include <linux/netdevice.h> |
11 | #include <linux/gfp.h> |
12 | #include <linux/skbuff.h> |
13 | #include <linux/types.h> |
14 | #include <linux/pagemap.h> |
15 | #include <linux/udp.h> |
16 | #include <linux/sunrpc/xdr.h> |
17 | |
18 | |
19 | /** |
20 | * xdr_skb_read_bits - copy some data bits from skb to internal buffer |
21 | * @desc: sk_buff copy helper |
22 | * @to: copy destination |
23 | * @len: number of bytes to copy |
24 | * |
25 | * Possibly called several times to iterate over an sk_buff and copy |
26 | * data out of it. |
27 | */ |
28 | size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len) |
29 | { |
30 | if (len > desc->count) |
31 | len = desc->count; |
32 | if (unlikely(skb_copy_bits(desc->skb, desc->offset, to, len))) |
33 | return 0; |
34 | desc->count -= len; |
35 | desc->offset += len; |
36 | return len; |
37 | } |
38 | EXPORT_SYMBOL_GPL(xdr_skb_read_bits); |
39 | |
40 | /** |
41 | * xdr_skb_read_and_csum_bits - copy and checksum from skb to buffer |
42 | * @desc: sk_buff copy helper |
43 | * @to: copy destination |
44 | * @len: number of bytes to copy |
45 | * |
46 | * Same as skb_read_bits, but calculate a checksum at the same time. |
47 | */ |
48 | static size_t xdr_skb_read_and_csum_bits(struct xdr_skb_reader *desc, void *to, size_t len) |
49 | { |
50 | unsigned int pos; |
51 | __wsum csum2; |
52 | |
53 | if (len > desc->count) |
54 | len = desc->count; |
55 | pos = desc->offset; |
56 | csum2 = skb_copy_and_csum_bits(desc->skb, pos, to, len, 0); |
57 | desc->csum = csum_block_add(desc->csum, csum2, pos); |
58 | desc->count -= len; |
59 | desc->offset += len; |
60 | return len; |
61 | } |
62 | |
63 | /** |
64 | * xdr_partial_copy_from_skb - copy data out of an skb |
65 | * @xdr: target XDR buffer |
66 | * @base: starting offset |
67 | * @desc: sk_buff copy helper |
68 | * @copy_actor: virtual method for copying data |
69 | * |
70 | */ |
71 | ssize_t xdr_partial_copy_from_skb(struct xdr_buf *xdr, unsigned int base, struct xdr_skb_reader *desc, xdr_skb_read_actor copy_actor) |
72 | { |
73 | struct page **ppage = xdr->pages; |
74 | unsigned int len, pglen = xdr->page_len; |
75 | ssize_t copied = 0; |
76 | size_t ret; |
77 | |
78 | len = xdr->head[0].iov_len; |
79 | if (base < len) { |
80 | len -= base; |
81 | ret = copy_actor(desc, (char *)xdr->head[0].iov_base + base, len); |
82 | copied += ret; |
83 | if (ret != len || !desc->count) |
84 | goto out; |
85 | base = 0; |
86 | } else |
87 | base -= len; |
88 | |
89 | if (unlikely(pglen == 0)) |
90 | goto copy_tail; |
91 | if (unlikely(base >= pglen)) { |
92 | base -= pglen; |
93 | goto copy_tail; |
94 | } |
95 | if (base || xdr->page_base) { |
96 | pglen -= base; |
97 | base += xdr->page_base; |
98 | ppage += base >> PAGE_CACHE_SHIFT; |
99 | base &= ~PAGE_CACHE_MASK; |
100 | } |
101 | do { |
102 | char *kaddr; |
103 | |
104 | /* ACL likes to be lazy in allocating pages - ACLs |
105 | * are small by default but can get huge. */ |
106 | if (unlikely(*ppage == NULL)) { |
107 | *ppage = alloc_page(GFP_ATOMIC); |
108 | if (unlikely(*ppage == NULL)) { |
109 | if (copied == 0) |
110 | copied = -ENOMEM; |
111 | goto out; |
112 | } |
113 | } |
114 | |
115 | len = PAGE_CACHE_SIZE; |
116 | kaddr = kmap_atomic(*ppage, KM_SKB_SUNRPC_DATA); |
117 | if (base) { |
118 | len -= base; |
119 | if (pglen < len) |
120 | len = pglen; |
121 | ret = copy_actor(desc, kaddr + base, len); |
122 | base = 0; |
123 | } else { |
124 | if (pglen < len) |
125 | len = pglen; |
126 | ret = copy_actor(desc, kaddr, len); |
127 | } |
128 | flush_dcache_page(*ppage); |
129 | kunmap_atomic(kaddr, KM_SKB_SUNRPC_DATA); |
130 | copied += ret; |
131 | if (ret != len || !desc->count) |
132 | goto out; |
133 | ppage++; |
134 | } while ((pglen -= len) != 0); |
135 | copy_tail: |
136 | len = xdr->tail[0].iov_len; |
137 | if (base < len) |
138 | copied += copy_actor(desc, (char *)xdr->tail[0].iov_base + base, len - base); |
139 | out: |
140 | return copied; |
141 | } |
142 | EXPORT_SYMBOL_GPL(xdr_partial_copy_from_skb); |
143 | |
144 | /** |
145 | * csum_partial_copy_to_xdr - checksum and copy data |
146 | * @xdr: target XDR buffer |
147 | * @skb: source skb |
148 | * |
149 | * We have set things up such that we perform the checksum of the UDP |
150 | * packet in parallel with the copies into the RPC client iovec. -DaveM |
151 | */ |
152 | int csum_partial_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb) |
153 | { |
154 | struct xdr_skb_reader desc; |
155 | |
156 | desc.skb = skb; |
157 | desc.offset = sizeof(struct udphdr); |
158 | desc.count = skb->len - desc.offset; |
159 | |
160 | if (skb_csum_unnecessary(skb)) |
161 | goto no_checksum; |
162 | |
163 | desc.csum = csum_partial(skb->data, desc.offset, skb->csum); |
164 | if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_and_csum_bits) < 0) |
165 | return -1; |
166 | if (desc.offset != skb->len) { |
167 | __wsum csum2; |
168 | csum2 = skb_checksum(skb, desc.offset, skb->len - desc.offset, 0); |
169 | desc.csum = csum_block_add(desc.csum, csum2, desc.offset); |
170 | } |
171 | if (desc.count) |
172 | return -1; |
173 | if (csum_fold(desc.csum)) |
174 | return -1; |
175 | if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE)) |
176 | netdev_rx_csum_fault(skb->dev); |
177 | return 0; |
178 | no_checksum: |
179 | if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0) |
180 | return -1; |
181 | if (desc.count) |
182 | return -1; |
183 | return 0; |
184 | } |
185 | EXPORT_SYMBOL_GPL(csum_partial_copy_to_xdr); |
186 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9