1 /* 2 * Copyright (C) 2011-2013 Matteo Landi, Luigi Rizzo. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions are 6 * met: 7 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the 14 * distribution. 15 * 16 * 3. Neither the name of the authors nor the names of their contributors 17 * may be used to endorse or promote products derived from this 18 * software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY MATTEO LANDI AND CONTRIBUTORS "AS IS" AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 23 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL MATTEO LANDI OR CONTRIBUTORS 24 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 30 * THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * $FreeBSD$ 35 * 36 * Definitions of constants and the structures used by the netmap 37 * framework, for the part visible to both kernel and userspace. 38 * Detailed info on netmap is available with "man netmap" or at 39 * 40 * http://info.iet.unipi.it/~luigi/netmap/ 41 */ 42 43 #ifndef _NET_NETMAP_H_ 44 #define _NET_NETMAP_H_ 45 46 /* 47 * --- Netmap data structures --- 48 * 49 * The data structures used by netmap are shown below. Those in 50 * capital letters are in an mmapp()ed area shared with userspace, 51 * while others are private to the kernel. 52 * Shared structures do not contain pointers but only memory 53 * offsets, so that addressing is portable between kernel and userspace. 54 55 56 softc 57 +----------------+ 58 | standard fields| 59 | if_pspare[0] ----------+ 60 +----------------+ | 61 | 62 +----------------+<------+ 63 |(netmap_adapter)| 64 | | netmap_kring 65 | tx_rings *--------------------------------->+---------------+ 66 | | netmap_kring | ring *---------. 67 | rx_rings *--------->+---------------+ | nr_hwcur | | 68 +----------------+ | ring *--------. | nr_hwavail | V 69 | nr_hwcur | | | selinfo | | 70 | nr_hwavail | | +---------------+ . 71 | selinfo | | | ... | . 72 +---------------+ | |(ntx+1 entries)| 73 | .... | | | | 74 |(nrx+1 entries)| | +---------------+ 75 | | | 76 KERNEL +---------------+ | 77 | 78 ==================================================================== 79 | 80 USERSPACE | NETMAP_RING 81 +---->+-------------+ 82 / | cur | 83 NETMAP_IF (nifp, one per file desc.) / | avail | 84 +---------------+ / | buf_ofs | 85 | ni_tx_rings | / +=============+ 86 | ni_rx_rings | / | buf_idx | slot[0] 87 | | / | len, flags | 88 | | / +-------------+ 89 +===============+ / | buf_idx | slot[1] 90 | txring_ofs[0] | (rel.to nifp)--' | len, flags | 91 | txring_ofs[1] | +-------------+ 92 (num_rings+1 entries) (nr_num_slots entries) 93 | txring_ofs[n] | | buf_idx | slot[n-1] 94 +---------------+ | len, flags | 95 | rxring_ofs[0] | +-------------+ 96 | rxring_ofs[1] | 97 (num_rings+1 entries) 98 | txring_ofs[n] | 99 +---------------+ 100 101 * The private descriptor ('softc' or 'adapter') of each interface 102 * is extended with a "struct netmap_adapter" containing netmap-related 103 * info (see description in dev/netmap/netmap_kernel.h. 104 * Among other things, tx_rings and rx_rings point to the arrays of 105 * "struct netmap_kring" which in turn reache the various 106 * "struct netmap_ring", shared with userspace. 107 108 * The NETMAP_RING is the userspace-visible replica of the NIC ring. 109 * Each slot has the index of a buffer, its length and some flags. 110 * In user space, the buffer address is computed as 111 * (char *)ring + buf_ofs + index*NETMAP_BUF_SIZE 112 * In the kernel, buffers do not necessarily need to be contiguous, 113 * and the virtual and physical addresses are derived through 114 * a lookup table. 115 * 116 * struct netmap_slot: 117 * 118 * buf_idx is the index of the buffer associated to the slot. 119 * len is the length of the payload 120 * NS_BUF_CHANGED must be set whenever userspace wants 121 * to change buf_idx (it might be necessary to 122 * reprogram the NIC slot) 123 * NS_REPORT must be set if we want the NIC to generate an interrupt 124 * when this slot is used. Leaving it to 0 improves 125 * performance. 126 * NS_FORWARD if set on a receive ring, and the device is in 127 * transparent mode, buffers released with the flag set 128 * will be forwarded to the 'other' side (host stack 129 * or NIC, respectively) on the next select() or ioctl() 130 * 131 * The following will be supported from NETMAP_API = 5 132 * NS_NO_LEARN on a VALE switch, do not 'learn' the source port for 133 * this packet. 134 * NS_INDIRECT the netmap buffer contains a 64-bit pointer to 135 * the actual userspace buffer. This may be useful 136 * to reduce copies in a VM environment. 137 * NS_MOREFRAG Part of a multi-segment frame. The last (or only) 138 * segment must not have this flag. 139 * NS_PORT_MASK the high 8 bits of the flag, if not zero, indicate the 140 * destination port for the VALE switch, overriding 141 * the lookup table. 142 */ 143 144 struct netmap_slot { 145 uint32_t buf_idx; /* buffer index */ 146 uint16_t len; /* packet length, to be copied to/from the hw ring */ 147 uint16_t flags; /* buf changed, etc. */ 148 #define NS_BUF_CHANGED 0x0001 /* must resync the map, buffer changed */ 149 #define NS_REPORT 0x0002 /* ask the hardware to report results 150 * e.g. by generating an interrupt 151 */ 152 #define NS_FORWARD 0x0004 /* pass packet to the other endpoint 153 * (host stack or device) 154 */ 155 #define NS_NO_LEARN 0x0008 156 #define NS_INDIRECT 0x0010 157 #define NS_MOREFRAG 0x0020 158 #define NS_PORT_SHIFT 8 159 #define NS_PORT_MASK (0xff << NS_PORT_SHIFT) 160 }; 161 162 /* 163 * Netmap representation of a TX or RX ring (also known as "queue"). 164 * This is a queue implemented as a fixed-size circular array. 165 * At the software level, two fields are important: avail and cur. 166 * 167 * In TX rings: 168 * avail indicates the number of slots available for transmission. 169 * It is updated by the kernel after every netmap system call. 170 * It MUST BE decremented by the application when it appends a 171 * packet. 172 * cur indicates the slot to use for the next packet 173 * to send (i.e. the "tail" of the queue). 174 * It MUST BE incremented by the application before 175 * netmap system calls to reflect the number of newly 176 * sent packets. 177 * It is checked by the kernel on netmap system calls 178 * (normally unmodified by the kernel unless invalid). 179 * 180 * The kernel side of netmap uses two additional fields in its own 181 * private ring structure, netmap_kring: 182 * nr_hwcur is a copy of nr_cur on an NIOCTXSYNC. 183 * nr_hwavail is the number of slots known as available by the 184 * hardware. It is updated on an INTR (inc by the 185 * number of packets sent) and on a NIOCTXSYNC 186 * (decrease by nr_cur - nr_hwcur) 187 * A special case, nr_hwavail is -1 if the transmit 188 * side is idle (no pending transmits). 189 * 190 * In RX rings: 191 * avail is the number of packets available (possibly 0). 192 * It MUST BE decremented by the application when it consumes 193 * a packet, and it is updated to nr_hwavail on a NIOCRXSYNC 194 * cur indicates the first slot that contains a packet not 195 * processed yet (the "head" of the queue). 196 * It MUST BE incremented by the software when it consumes 197 * a packet. 198 * reserved indicates the number of buffers before 'cur' 199 * that the application has still in use. Normally 0, 200 * it MUST BE incremented by the application when it 201 * does not return the buffer immediately, and decremented 202 * when the buffer is finally freed. 203 * 204 * The kernel side of netmap uses two additional fields in the kring: 205 * nr_hwcur is a copy of nr_cur on an NIOCRXSYNC 206 * nr_hwavail is the number of packets available. It is updated 207 * on INTR (inc by the number of new packets arrived) 208 * and on NIOCRXSYNC (decreased by nr_cur - nr_hwcur). 209 * 210 * DATA OWNERSHIP/LOCKING: 211 * The netmap_ring is owned by the user program and it is only 212 * accessed or modified in the upper half of the kernel during 213 * a system call. 214 * 215 * The netmap_kring is only modified by the upper half of the kernel. 216 * 217 * FLAGS 218 * NR_TIMESTAMP updates the 'ts' field on each syscall. This is 219 * a global timestamp for all packets. 220 * NR_RX_TSTMP if set, the last 64 byte in each buffer will 221 * contain a timestamp for the frame supplied by 222 * the hardware (if supported) 223 * NR_FORWARD if set, the NS_FORWARD flag in each slot of the 224 * RX ring is checked, and if set the packet is 225 * passed to the other side (host stack or device, 226 * respectively). This permits bpf-like behaviour 227 * or transparency for selected packets. 228 */ 229 struct netmap_ring { 230 /* 231 * nr_buf_base_ofs is meant to be used through macros. 232 * It contains the offset of the buffer region from this 233 * descriptor. 234 */ 235 const ssize_t buf_ofs; 236 const uint32_t num_slots; /* number of slots in the ring. */ 237 uint32_t avail; /* number of usable slots */ 238 uint32_t cur; /* 'current' r/w position */ 239 uint32_t reserved; /* not refilled before current */ 240 241 const uint16_t nr_buf_size; 242 uint16_t flags; 243 #define NR_TIMESTAMP 0x0002 /* set timestamp on *sync() */ 244 #define NR_FORWARD 0x0004 /* enable NS_FORWARD for ring */ 245 #define NR_RX_TSTMP 0x0008 /* set rx timestamp in slots */ 246 247 struct timeval ts; /* time of last *sync() */ 248 249 /* the slots follow. This struct has variable size */ 250 struct netmap_slot slot[0]; /* array of slots. */ 251 }; 252 253 254 /* 255 * Netmap representation of an interface and its queue(s). 256 * There is one netmap_if for each file descriptor on which we want 257 * to select/poll. We assume that on each interface has the same number 258 * of receive and transmit queues. 259 * select/poll operates on one or all pairs depending on the value of 260 * nmr_queueid passed on the ioctl. 261 */ 262 struct netmap_if { 263 char ni_name[IFNAMSIZ]; /* name of the interface. */ 264 const u_int ni_version; /* API version, currently unused */ 265 const u_int ni_rx_rings; /* number of rx rings */ 266 const u_int ni_tx_rings; /* if zero, same as ni_rx_rings */ 267 /* 268 * The following array contains the offset of each netmap ring 269 * from this structure. The first ni_tx_queues+1 entries refer 270 * to the tx rings, the next ni_rx_queues+1 refer to the rx rings 271 * (the last entry in each block refers to the host stack rings). 272 * The area is filled up by the kernel on NIOCREG, 273 * and then only read by userspace code. 274 */ 275 const ssize_t ring_ofs[0]; 276 }; 277 278 #ifndef NIOCREGIF 279 /* 280 * ioctl names and related fields 281 * 282 * NIOCGINFO takes a struct ifreq, the interface name is the input, 283 * the outputs are number of queues and number of descriptor 284 * for each queue (useful to set number of threads etc.). 285 * 286 * NIOCREGIF takes an interface name within a struct ifreq, 287 * and activates netmap mode on the interface (if possible). 288 * 289 * For vale ports, starting with NETMAP_API = 5, 290 * nr_tx_rings and nr_rx_rings specify how many software rings 291 * are created (0 means 1). 292 * 293 * NIOCREGIF is also used to attach a NIC to a VALE switch. 294 * In this case the name is vale*:ifname, and "nr_cmd" 295 * is set to 'NETMAP_BDG_ATTACH' or 'NETMAP_BDG_DETACH'. 296 * nr_ringid specifies which rings should be attached, 0 means all, 297 * NETMAP_HW_RING + n means only the n-th ring. 298 * The process can terminate after the interface has been attached. 299 * 300 * NIOCUNREGIF unregisters the interface associated to the fd. 301 * this is deprecated and will go away. 302 * 303 * NIOCTXSYNC, NIOCRXSYNC synchronize tx or rx queues, 304 * whose identity is set in NIOCREGIF through nr_ringid 305 * 306 * NETMAP_API is the API version. 307 */ 308 309 /* 310 * struct nmreq overlays a struct ifreq 311 */ 312 struct nmreq { 313 char nr_name[IFNAMSIZ]; 314 uint32_t nr_version; /* API version */ 315 #define NETMAP_API 4 /* current version */ 316 uint32_t nr_offset; /* nifp offset in the shared region */ 317 uint32_t nr_memsize; /* size of the shared region */ 318 uint32_t nr_tx_slots; /* slots in tx rings */ 319 uint32_t nr_rx_slots; /* slots in rx rings */ 320 uint16_t nr_tx_rings; /* number of tx rings */ 321 uint16_t nr_rx_rings; /* number of rx rings */ 322 uint16_t nr_ringid; /* ring(s) we care about */ 323 #define NETMAP_HW_RING 0x4000 /* low bits indicate one hw ring */ 324 #define NETMAP_SW_RING 0x2000 /* process the sw ring */ 325 #define NETMAP_NO_TX_POLL 0x1000 /* no automatic txsync on poll */ 326 #define NETMAP_RING_MASK 0xfff /* the ring number */ 327 uint16_t nr_cmd; 328 #define NETMAP_BDG_ATTACH 1 /* attach the NIC */ 329 #define NETMAP_BDG_DETACH 2 /* detach the NIC */ 330 #define NETMAP_BDG_LOOKUP_REG 3 /* register lookup function */ 331 #define NETMAP_BDG_LIST 4 /* get bridge's info */ 332 uint16_t nr_arg1; 333 #define NETMAP_BDG_HOST 1 /* attach the host stack on ATTACH */ 334 uint16_t nr_arg2; 335 uint32_t spare2[3]; 336 }; 337 338 /* 339 * FreeBSD uses the size value embedded in the _IOWR to determine 340 * how much to copy in/out. So we need it to match the actual 341 * data structure we pass. We put some spares in the structure 342 * to ease compatibility with other versions 343 */ 344 #define NIOCGINFO _IOWR('i', 145, struct nmreq) /* return IF info */ 345 #define NIOCREGIF _IOWR('i', 146, struct nmreq) /* interface register */ 346 #define NIOCUNREGIF _IO('i', 147) /* interface unregister */ 347 #define NIOCTXSYNC _IO('i', 148) /* sync tx queues */ 348 #define NIOCRXSYNC _IO('i', 149) /* sync rx queues */ 349 #endif /* !NIOCREGIF */ 350 351 #endif /* _NET_NETMAP_H_ */ 352