[infiniband] Use "%#lx" as format specifier for queue pair numbers
[ipxe.git] / src / net / fragment.c
1 /*
2 * Copyright (C) 2013 Michael Brown <mbrown@fensystems.co.uk>.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or any later version.
8 *
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
17 * 02110-1301, USA.
18 *
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
22 */
23
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
25
26 #include <stdint.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <ipxe/retry.h>
30 #include <ipxe/timer.h>
31 #include <ipxe/ipstat.h>
32 #include <ipxe/fragment.h>
33
34 /** @file
35 *
36 * Fragment reassembly
37 *
38 */
39
40 /**
41 * Expire fragment reassembly buffer
42 *
43 * @v timer Retry timer
44 * @v fail Failure indicator
45 */
46 static void fragment_expired ( struct retry_timer *timer, int fail __unused ) {
47 struct fragment *fragment =
48 container_of ( timer, struct fragment, timer );
49
50 DBGC ( fragment, "FRAG %p expired\n", fragment );
51 free_iob ( fragment->iobuf );
52 list_del ( &fragment->list );
53 fragment->fragments->stats->reasm_fails++;
54 free ( fragment );
55 }
56
57 /**
58 * Find fragment reassembly buffer
59 *
60 * @v fragments Fragment reassembler
61 * @v iobuf I/O buffer
62 * @v hdrlen Length of non-fragmentable potion of I/O buffer
63 * @ret fragment Fragment reassembly buffer, or NULL if not found
64 */
65 static struct fragment * fragment_find ( struct fragment_reassembler *fragments,
66 struct io_buffer *iobuf,
67 size_t hdrlen ) {
68 struct fragment *fragment;
69
70 list_for_each_entry ( fragment, &fragments->list, list ) {
71 if ( fragments->is_fragment ( fragment, iobuf, hdrlen ) )
72 return fragment;
73 }
74 return NULL;
75 }
76
77 /**
78 * Reassemble packet
79 *
80 * @v fragments Fragment reassembler
81 * @v iobuf I/O buffer
82 * @v hdrlen Length of non-fragmentable potion of I/O buffer
83 * @ret iobuf Reassembled packet, or NULL
84 *
85 * This function takes ownership of the I/O buffer. Note that the
86 * length of the non-fragmentable portion may be modified.
87 */
88 struct io_buffer * fragment_reassemble ( struct fragment_reassembler *fragments,
89 struct io_buffer *iobuf,
90 size_t *hdrlen ) {
91 struct fragment *fragment;
92 struct io_buffer *new_iobuf;
93 size_t new_len;
94 size_t offset;
95 size_t expected_offset;
96 int more_frags;
97
98 /* Update statistics */
99 fragments->stats->reasm_reqds++;
100
101 /* Find matching fragment reassembly buffer, if any */
102 fragment = fragment_find ( fragments, iobuf, *hdrlen );
103
104 /* Drop out-of-order fragments */
105 offset = fragments->fragment_offset ( iobuf, *hdrlen );
106 expected_offset = ( fragment ? ( iob_len ( fragment->iobuf ) -
107 fragment->hdrlen ) : 0 );
108 if ( offset != expected_offset ) {
109 DBGC ( fragment, "FRAG %p dropping out-of-sequence fragment "
110 "[%zd,%zd), expected [%zd,...)\n", fragment, offset,
111 ( offset + iob_len ( iobuf ) - *hdrlen ),
112 expected_offset );
113 goto drop;
114 }
115
116 /* Create or extend fragment reassembly buffer as applicable */
117 if ( ! fragment ) {
118
119 /* Create new fragment reassembly buffer */
120 fragment = zalloc ( sizeof ( *fragment ) );
121 if ( ! fragment )
122 goto drop;
123 list_add ( &fragment->list, &fragments->list );
124 fragment->iobuf = iobuf;
125 fragment->hdrlen = *hdrlen;
126 timer_init ( &fragment->timer, fragment_expired, NULL );
127 fragment->fragments = fragments;
128 DBGC ( fragment, "FRAG %p [0,%zd)\n", fragment,
129 ( iob_len ( iobuf ) - *hdrlen ) );
130
131 } else {
132
133 /* Check if this is the final fragment */
134 more_frags = fragments->more_fragments ( iobuf, *hdrlen );
135 DBGC ( fragment, "FRAG %p [%zd,%zd)%s\n", fragment,
136 offset, ( offset + iob_len ( iobuf ) - *hdrlen ),
137 ( more_frags ? "" : " complete" ) );
138
139 /* Extend fragment reassembly buffer. Preserve I/O
140 * buffer headroom to allow for code which modifies
141 * and resends the buffer (e.g. ICMP echo responses).
142 */
143 iob_pull ( iobuf, *hdrlen );
144 new_len = ( iob_headroom ( fragment->iobuf ) +
145 iob_len ( fragment->iobuf ) + iob_len ( iobuf ) );
146 new_iobuf = alloc_iob ( new_len );
147 if ( ! new_iobuf ) {
148 DBGC ( fragment, "FRAG %p could not extend reassembly "
149 "buffer to %zd bytes\n", fragment, new_len );
150 goto drop;
151 }
152 iob_reserve ( new_iobuf, iob_headroom ( fragment->iobuf ) );
153 memcpy ( iob_put ( new_iobuf, iob_len ( fragment->iobuf ) ),
154 fragment->iobuf->data, iob_len ( fragment->iobuf ) );
155 memcpy ( iob_put ( new_iobuf, iob_len ( iobuf ) ),
156 iobuf->data, iob_len ( iobuf ) );
157 free_iob ( fragment->iobuf );
158 fragment->iobuf = new_iobuf;
159 free_iob ( iobuf );
160
161 /* Stop fragment reassembly timer */
162 stop_timer ( &fragment->timer );
163
164 /* If this is the final fragment, return it */
165 if ( ! more_frags ) {
166 iobuf = fragment->iobuf;
167 *hdrlen = fragment->hdrlen;
168 list_del ( &fragment->list );
169 free ( fragment );
170 fragments->stats->reasm_oks++;
171 return iobuf;
172 }
173 }
174
175 /* (Re)start fragment reassembly timer */
176 start_timer_fixed ( &fragment->timer, FRAGMENT_TIMEOUT );
177
178 return NULL;
179
180 drop:
181 fragments->stats->reasm_fails++;
182 free_iob ( iobuf );
183 return NULL;
184 }