1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2009 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 /* 32 * IEEE 802.11 age queue support. 33 */ 34 #include "opt_wlan.h" 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/kernel.h> 39 #include <sys/malloc.h> 40 41 #include <sys/socket.h> 42 43 #include <net/if.h> 44 #include <net/if_var.h> 45 #include <net/if_media.h> 46 #include <net/ethernet.h> 47 48 #include <net80211/ieee80211_var.h> 49 50 /* 51 * Initialize an ageq. 52 */ 53 void 54 ieee80211_ageq_init(struct ieee80211_ageq *aq, int maxlen, const char *name) 55 { 56 memset(aq, 0, sizeof(*aq)); 57 aq->aq_maxlen = maxlen; 58 IEEE80211_AGEQ_INIT(aq, name); /* OS-dependent setup */ 59 } 60 61 /* 62 * Cleanup an ageq initialized with ieee80211_ageq_init. Note 63 * the queue is assumed empty; this can be done with ieee80211_ageq_drain. 64 */ 65 void 66 ieee80211_ageq_cleanup(struct ieee80211_ageq *aq) 67 { 68 KASSERT(aq->aq_len == 0, ("%d frames on ageq", aq->aq_len)); 69 IEEE80211_AGEQ_DESTROY(aq); /* OS-dependent cleanup */ 70 } 71 72 /* 73 * Free an mbuf according to ageq rules: if marked as holding 74 * and 802.11 frame then also reclaim a node reference from 75 * the packet header; this handles packets q'd in the tx path. 76 */ 77 static void 78 ageq_mfree(struct mbuf *m) 79 { 80 if (m->m_flags & M_ENCAP) { 81 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif; 82 ieee80211_free_node(ni); 83 } 84 m->m_nextpkt = NULL; 85 m_freem(m); 86 } 87 88 /* 89 * Free a list of mbufs using ageq rules (see above). 90 */ 91 void 92 ieee80211_ageq_mfree(struct mbuf *m) 93 { 94 struct mbuf *next; 95 96 for (; m != NULL; m = next) { 97 next = m->m_nextpkt; 98 ageq_mfree(m); 99 } 100 } 101 102 /* 103 * Append an mbuf to the ageq and mark it with the specified max age 104 * If the frame is not removed before the age (in seconds) expires 105 * then it is reclaimed (along with any node reference). 106 */ 107 int 108 ieee80211_ageq_append(struct ieee80211_ageq *aq, struct mbuf *m, int age) 109 { 110 IEEE80211_AGEQ_LOCK(aq); 111 if (__predict_true(aq->aq_len < aq->aq_maxlen)) { 112 if (aq->aq_tail == NULL) { 113 aq->aq_head = m; 114 } else { 115 aq->aq_tail->m_nextpkt = m; 116 age -= M_AGE_GET(aq->aq_head); 117 } 118 KASSERT(age >= 0, ("age %d", age)); 119 M_AGE_SET(m, age); 120 m->m_nextpkt = NULL; 121 aq->aq_tail = m; 122 aq->aq_len++; 123 IEEE80211_AGEQ_UNLOCK(aq); 124 return 0; 125 } else { 126 /* 127 * No space, drop and cleanup references. 128 */ 129 aq->aq_drops++; 130 IEEE80211_AGEQ_UNLOCK(aq); 131 /* XXX tail drop? */ 132 ageq_mfree(m); 133 return ENOSPC; 134 } 135 } 136 137 /* 138 * Drain/reclaim all frames from an ageq. 139 */ 140 void 141 ieee80211_ageq_drain(struct ieee80211_ageq *aq) 142 { 143 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, NULL)); 144 } 145 146 /* 147 * Drain/reclaim frames associated with a specific node from an ageq. 148 */ 149 void 150 ieee80211_ageq_drain_node(struct ieee80211_ageq *aq, 151 struct ieee80211_node *ni) 152 { 153 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, ni)); 154 } 155 156 /* 157 * Age frames on the age queue. Ages are stored as time 158 * deltas (in seconds) relative to the head so we can check 159 * and/or adjust only the head of the list. If a frame's age 160 * exceeds the time quanta then remove it. The list of removed 161 * frames is returned to the caller joined by m_nextpkt. 162 */ 163 struct mbuf * 164 ieee80211_ageq_age(struct ieee80211_ageq *aq, int quanta) 165 { 166 struct mbuf *head, **phead; 167 struct mbuf *m; 168 169 phead = &head; 170 if (aq->aq_len != 0) { 171 IEEE80211_AGEQ_LOCK(aq); 172 while ((m = aq->aq_head) != NULL && M_AGE_GET(m) < quanta) { 173 if ((aq->aq_head = m->m_nextpkt) == NULL) 174 aq->aq_tail = NULL; 175 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len)); 176 aq->aq_len--; 177 /* add to private list for return */ 178 *phead = m; 179 phead = &m->m_nextpkt; 180 } 181 if (m != NULL) 182 M_AGE_SUB(m, quanta); 183 IEEE80211_AGEQ_UNLOCK(aq); 184 } 185 *phead = NULL; 186 return head; 187 } 188 189 /* 190 * Remove all frames matching the specified node identifier 191 * (NULL matches all). Frames are returned as a list joined 192 * by m_nextpkt. 193 */ 194 struct mbuf * 195 ieee80211_ageq_remove(struct ieee80211_ageq *aq, 196 struct ieee80211_node *match) 197 { 198 struct mbuf *m, **prev, *ohead; 199 struct mbuf *head, **phead; 200 201 IEEE80211_AGEQ_LOCK(aq); 202 ohead = aq->aq_head; 203 prev = &aq->aq_head; 204 phead = &head; 205 while ((m = *prev) != NULL) { 206 if (match != NULL && m->m_pkthdr.rcvif != (void *) match) { 207 prev = &m->m_nextpkt; 208 continue; 209 } 210 /* 211 * Adjust q length. 212 */ 213 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len)); 214 aq->aq_len--; 215 /* 216 * Remove from forward list; tail pointer is harder. 217 */ 218 if (aq->aq_tail == m) { 219 KASSERT(m->m_nextpkt == NULL, ("not last")); 220 if (aq->aq_head == m) { /* list empty */ 221 KASSERT(aq->aq_len == 0, 222 ("not empty, len %d", aq->aq_len)); 223 aq->aq_tail = NULL; 224 } else { /* must be one before */ 225 aq->aq_tail = (struct mbuf *)((uintptr_t)prev - 226 offsetof(struct mbuf, m_nextpkt)); 227 } 228 } 229 *prev = m->m_nextpkt; 230 231 /* add to private list for return */ 232 *phead = m; 233 phead = &m->m_nextpkt; 234 } 235 if (head == ohead && aq->aq_head != NULL) /* correct age */ 236 M_AGE_SET(aq->aq_head, M_AGE_GET(head)); 237 IEEE80211_AGEQ_UNLOCK(aq); 238 239 *phead = NULL; 240 return head; 241 } 242