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 #include <sys/malloc.h> 38 39 #include <sys/socket.h> 40 41 #include <net/if.h> 42 #include <net/if_var.h> 43 #include <net/if_media.h> 44 #include <net/ethernet.h> 45 46 #include <net80211/ieee80211_var.h> 47 48 /* 49 * Initialize an ageq. 50 */ 51 void 52 ieee80211_ageq_init(struct ieee80211_ageq *aq, int maxlen, const char *name) 53 { 54 memset(aq, 0, sizeof(*aq)); 55 aq->aq_maxlen = maxlen; 56 IEEE80211_AGEQ_INIT(aq, name); /* OS-dependent setup */ 57 } 58 59 /* 60 * Cleanup an ageq initialized with ieee80211_ageq_init. Note 61 * the queue is assumed empty; this can be done with ieee80211_ageq_drain. 62 */ 63 void 64 ieee80211_ageq_cleanup(struct ieee80211_ageq *aq) 65 { 66 KASSERT(aq->aq_len == 0, ("%d frames on ageq", aq->aq_len)); 67 IEEE80211_AGEQ_DESTROY(aq); /* OS-dependent cleanup */ 68 } 69 70 /* 71 * Free an mbuf according to ageq rules: if marked as holding 72 * and 802.11 frame then also reclaim a node reference from 73 * the packet header; this handles packets q'd in the tx path. 74 */ 75 static void 76 ageq_mfree(struct mbuf *m) 77 { 78 if (m->m_flags & M_ENCAP) { 79 struct ieee80211_node *ni = (void *) m->m_pkthdr.rcvif; 80 ieee80211_free_node(ni); 81 } 82 m->m_nextpkt = NULL; 83 m_freem(m); 84 } 85 86 /* 87 * Free a list of mbufs using ageq rules (see above). 88 */ 89 void 90 ieee80211_ageq_mfree(struct mbuf *m) 91 { 92 struct mbuf *next; 93 94 for (; m != NULL; m = next) { 95 next = m->m_nextpkt; 96 ageq_mfree(m); 97 } 98 } 99 100 /* 101 * Append an mbuf to the ageq and mark it with the specified max age 102 * If the frame is not removed before the age (in seconds) expires 103 * then it is reclaimed (along with any node reference). 104 */ 105 int 106 ieee80211_ageq_append(struct ieee80211_ageq *aq, struct mbuf *m, int age) 107 { 108 IEEE80211_AGEQ_LOCK(aq); 109 if (__predict_true(aq->aq_len < aq->aq_maxlen)) { 110 if (aq->aq_tail == NULL) { 111 aq->aq_head = m; 112 } else { 113 aq->aq_tail->m_nextpkt = m; 114 age -= M_AGE_GET(aq->aq_head); 115 } 116 KASSERT(age >= 0, ("age %d", age)); 117 M_AGE_SET(m, age); 118 m->m_nextpkt = NULL; 119 aq->aq_tail = m; 120 aq->aq_len++; 121 IEEE80211_AGEQ_UNLOCK(aq); 122 return 0; 123 } else { 124 /* 125 * No space, drop and cleanup references. 126 */ 127 aq->aq_drops++; 128 IEEE80211_AGEQ_UNLOCK(aq); 129 /* XXX tail drop? */ 130 ageq_mfree(m); 131 return ENOSPC; 132 } 133 } 134 135 /* 136 * Drain/reclaim all frames from an ageq. 137 */ 138 void 139 ieee80211_ageq_drain(struct ieee80211_ageq *aq) 140 { 141 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, NULL)); 142 } 143 144 /* 145 * Drain/reclaim frames associated with a specific node from an ageq. 146 */ 147 void 148 ieee80211_ageq_drain_node(struct ieee80211_ageq *aq, 149 struct ieee80211_node *ni) 150 { 151 ieee80211_ageq_mfree(ieee80211_ageq_remove(aq, ni)); 152 } 153 154 /* 155 * Age frames on the age queue. Ages are stored as time 156 * deltas (in seconds) relative to the head so we can check 157 * and/or adjust only the head of the list. If a frame's age 158 * exceeds the time quanta then remove it. The list of removed 159 * frames is returned to the caller joined by m_nextpkt. 160 */ 161 struct mbuf * 162 ieee80211_ageq_age(struct ieee80211_ageq *aq, int quanta) 163 { 164 struct mbuf *head, **phead; 165 struct mbuf *m; 166 167 phead = &head; 168 if (aq->aq_len != 0) { 169 IEEE80211_AGEQ_LOCK(aq); 170 while ((m = aq->aq_head) != NULL && M_AGE_GET(m) < quanta) { 171 if ((aq->aq_head = m->m_nextpkt) == NULL) 172 aq->aq_tail = NULL; 173 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len)); 174 aq->aq_len--; 175 /* add to private list for return */ 176 *phead = m; 177 phead = &m->m_nextpkt; 178 } 179 if (m != NULL) 180 M_AGE_SUB(m, quanta); 181 IEEE80211_AGEQ_UNLOCK(aq); 182 } 183 *phead = NULL; 184 return head; 185 } 186 187 /* 188 * Remove all frames matching the specified node identifier 189 * (NULL matches all). Frames are returned as a list joined 190 * by m_nextpkt. 191 */ 192 struct mbuf * 193 ieee80211_ageq_remove(struct ieee80211_ageq *aq, 194 struct ieee80211_node *match) 195 { 196 struct mbuf *m, **prev, *ohead; 197 struct mbuf *head, **phead; 198 199 IEEE80211_AGEQ_LOCK(aq); 200 ohead = aq->aq_head; 201 prev = &aq->aq_head; 202 phead = &head; 203 while ((m = *prev) != NULL) { 204 if (match != NULL && m->m_pkthdr.rcvif != (void *) match) { 205 prev = &m->m_nextpkt; 206 continue; 207 } 208 /* 209 * Adjust q length. 210 */ 211 KASSERT(aq->aq_len > 0, ("aq len %d", aq->aq_len)); 212 aq->aq_len--; 213 /* 214 * Remove from forward list; tail pointer is harder. 215 */ 216 if (aq->aq_tail == m) { 217 KASSERT(m->m_nextpkt == NULL, ("not last")); 218 if (aq->aq_head == m) { /* list empty */ 219 KASSERT(aq->aq_len == 0, 220 ("not empty, len %d", aq->aq_len)); 221 aq->aq_tail = NULL; 222 } else { /* must be one before */ 223 aq->aq_tail = (struct mbuf *)((uintptr_t)prev - 224 offsetof(struct mbuf, m_nextpkt)); 225 } 226 } 227 *prev = m->m_nextpkt; 228 229 /* add to private list for return */ 230 *phead = m; 231 phead = &m->m_nextpkt; 232 } 233 if (head == ohead && aq->aq_head != NULL) /* correct age */ 234 M_AGE_SET(aq->aq_head, M_AGE_GET(head)); 235 IEEE80211_AGEQ_UNLOCK(aq); 236 237 *phead = NULL; 238 return head; 239 } 240