1 /*- 2 * Copyright (c) 2009 Sam Leffler, Errno Consulting 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * IEEE 802.11 age queue support. 31 */ 32 #include "opt_wlan.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 38 #include <sys/socket.h> 39 40 #include <net/if.h> 41 #include <net/if_media.h> 42 #include <net/ethernet.h> 43 44 #include <net80211/ieee80211_var.h> 45 46 /* 47 * Initialize an ageq. 48 */ 49 void 50 ieee80211_ageq_init(struct ieee80211_ageq *aq, int maxlen, const char *name) 51 { 52 memset(aq, 0, sizeof(*aq)); 53 aq->aq_maxlen = maxlen; 54 IEEE80211_AGEQ_INIT(aq, name); /* OS-dependent setup */ 55 } 56 57 /* 58 * Cleanup an ageq initialized with ieee80211_ageq_init. Note 59 * the queue is assumed empty; this can be done with ieee80211_ageq_drain. 60 */ 61 void 62 ieee80211_ageq_cleanup(struct ieee80211_ageq *aq) 63 { 64 KASSERT(aq->aq_len == 0, ("%d frames on ageq", aq->aq_len)); 65 IEEE80211_AGEQ_DESTROY(aq); /* OS-dependent cleanup */ 66 } 67 68 /* 69 * Free an mbuf according to ageq rules: if marked as holding 70 * and 802.11 frame then also reclaim a node reference from 71 * the packet header; this handles packets q'd in the tx path. 72 */ 73 static void 74 ageq_mfree(struct mbuf *m) 75 { 76 if (m->m_flags & M_ENCAP) { 77 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif; 78 ieee80211_free_node(ni); 79 } 80 m->m_nextpkt = NULL; 81 m_freem(m); 82 } 83 84 /* 85 * Free a list of mbufs using ageq rules (see above). 86 */ 87 void 88 ieee80211_ageq_mfree(struct mbuf *m) 89 { 90 struct mbuf *next; 91 92 for (; m != NULL; m = next) { 93 next = m->m_nextpkt; 94 ageq_mfree(m); 95 } 96 } 97 98 /* 99 * Append an mbuf to the ageq and mark it with the specified max age 100 * If the frame is not removed before the age (in seconds) expires 101 * then it is reclaimed (along with any node reference). 102 */ 103 int 104 ieee80211_ageq_append(struct ieee80211_ageq *aq, struct mbuf *m, int age) 105 { 106 IEEE80211_AGEQ_LOCK(aq); 107 if (__predict_true(aq->aq_len < aq->aq_maxlen)) { 108 if (aq->aq_tail == NULL) { 109 aq->aq_head = m; 110 } else { 111 aq->aq_tail->m_nextpkt = m; 112 age -= M_AGE_GET(aq->aq_head); 113 } 114 KASSERT(age >= 0, ("age %d", age)); 115 M_AGE_SET(m, age); 116 m->m_nextpkt = NULL; 117 aq->aq_tail = m; 118 aq->aq_len++; 119 IEEE80211_AGEQ_UNLOCK(aq); 120 return 0; 121 } else { 122 /* 123 * No space, drop and cleanup references. 124 */ 125 aq->aq_drops++; 126 IEEE80211_AGEQ_UNLOCK(aq); 127 /* XXX tail drop? */ 128 ageq_mfree(m); 129 return ENOSPC; 130 } 131 } 132 133 /* 134 * Drain/reclaim all frames from an ageq. 135 */ 136 void 137 ieee80211_ageq_drain(struct ieee80211_ageq *aq) 138 { 139 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, NULL)); 140 } 141 142 /* 143 * Drain/reclaim frames associated with a specific node from an ageq. 144 */ 145 void 146 ieee80211_ageq_drain_node(struct ieee80211_ageq *aq, 147 struct ieee80211_node *ni) 148 { 149 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, ni)); 150 } 151 152 /* 153 * Age frames on the age queue. Ages are stored as time 154 * deltas (in seconds) relative to the head so we can check 155 * and/or adjust only the head of the list. If a frame's age 156 * exceeds the time quanta then remove it. The list of removed 157 * frames is returned to the caller joined by m_nextpkt. 158 */ 159 struct mbuf * 160 ieee80211_ageq_age(struct ieee80211_ageq *aq, int quanta) 161 { 162 struct mbuf *head, **phead; 163 struct mbuf *m; 164 165 phead = &head; 166 if (aq->aq_len != 0) { 167 IEEE80211_AGEQ_LOCK(aq); 168 while ((m = aq->aq_head) != NULL && M_AGE_GET(m) < quanta) { 169 if ((aq->aq_head = m->m_nextpkt) == NULL) 170 aq->aq_tail = NULL; 171 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len)); 172 aq->aq_len--; 173 /* add to private list for return */ 174 *phead = m; 175 phead = &m->m_nextpkt; 176 } 177 if (m != NULL) 178 M_AGE_SUB(m, quanta); 179 IEEE80211_AGEQ_UNLOCK(aq); 180 } 181 *phead = NULL; 182 return head; 183 } 184 185 /* 186 * Remove all frames matching the specified node identifier 187 * (NULL matches all). Frames are returned as a list joined 188 * by m_nextpkt. 189 */ 190 struct mbuf * 191 ieee80211_ageq_remove(struct ieee80211_ageq *aq, 192 struct ieee80211_node *match) 193 { 194 struct mbuf *m, **prev, *ohead; 195 struct mbuf *head, **phead; 196 197 IEEE80211_AGEQ_LOCK(aq); 198 ohead = aq->aq_head; 199 prev = &aq->aq_head; 200 phead = &head; 201 while ((m = *prev) != NULL) { 202 if (match != NULL && m->m_pkthdr.rcvif != (void *) match) { 203 prev = &m->m_nextpkt; 204 continue; 205 } 206 /* 207 * Adjust q length. 208 */ 209 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len)); 210 aq->aq_len--; 211 /* 212 * Remove from forward list; tail pointer is harder. 213 */ 214 if (aq->aq_tail == m) { 215 KASSERT(m->m_nextpkt == NULL, ("not last")); 216 if (aq->aq_head == m) { /* list empty */ 217 KASSERT(aq->aq_len == 0, 218 ("not empty, len %d", aq->aq_len)); 219 aq->aq_tail = NULL; 220 } else { /* must be one before */ 221 aq->aq_tail = (struct mbuf *)((uintptr_t)prev - 222 offsetof(struct mbuf, m_nextpkt)); 223 } 224 } 225 *prev = m->m_nextpkt; 226 227 /* add to private list for return */ 228 *phead = m; 229 phead = &m->m_nextpkt; 230 } 231 if (head == ohead && aq->aq_head != NULL) /* correct age */ 232 M_AGE_SET(aq->aq_head, M_AGE_GET(head)); 233 IEEE80211_AGEQ_UNLOCK(aq); 234 235 *phead = NULL; 236 return head; 237 } 238