1 /*- 2 * Copyright (c) 2020-2022 The FreeBSD Foundation 3 * Copyright (c) 2021-2022 Bjoern A. Zeeb 4 * 5 * This software was developed by Björn Zeeb under sponsorship from 6 * the FreeBSD Foundation. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. 28 * 29 * $FreeBSD$ 30 */ 31 32 /* 33 * NOTE: this socket buffer compatibility code is highly EXPERIMENTAL. 34 * Do not rely on the internals of this implementation. They are highly 35 * likely to change as we will improve the integration to FreeBSD mbufs. 36 */ 37 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include "opt_ddb.h" 42 43 #include <sys/param.h> 44 #include <sys/types.h> 45 #include <sys/kernel.h> 46 #include <sys/malloc.h> 47 #include <sys/sysctl.h> 48 49 #ifdef DDB 50 #include <ddb/ddb.h> 51 #endif 52 53 #include <linux/skbuff.h> 54 #include <linux/slab.h> 55 #include <linux/gfp.h> 56 #ifdef __LP64__ 57 #include <linux/log2.h> 58 #endif 59 60 SYSCTL_DECL(_compat_linuxkpi); 61 SYSCTL_NODE(_compat_linuxkpi, OID_AUTO, skb, CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 62 "LinuxKPI skbuff"); 63 64 #ifdef SKB_DEBUG 65 int linuxkpi_debug_skb; 66 SYSCTL_INT(_compat_linuxkpi_skb, OID_AUTO, debug, CTLFLAG_RWTUN, 67 &linuxkpi_debug_skb, 0, "SKB debug level"); 68 #endif 69 70 #ifdef __LP64__ 71 /* 72 * Realtek wireless drivers (e.g., rtw88) require 32bit DMA in a single segment. 73 * busdma(9) has a hard time providing this currently for 3-ish pages at large 74 * quantities (see lkpi_pci_nseg1_fail in linux_pci.c). 75 * Work around this for now by allowing a tunable to enforce physical addresses 76 * allocation limits on 64bit platforms using "old-school" contigmalloc(9) to 77 * avoid bouncing. 78 */ 79 static int linuxkpi_skb_memlimit; 80 SYSCTL_INT(_compat_linuxkpi_skb, OID_AUTO, mem_limit, CTLFLAG_RDTUN, 81 &linuxkpi_skb_memlimit, 0, "SKB memory limit: 0=no limit, " 82 "1=32bit, 2=36bit, other=undef (currently 32bit)"); 83 #endif 84 85 static MALLOC_DEFINE(M_LKPISKB, "lkpiskb", "Linux KPI skbuff compat"); 86 87 struct sk_buff * 88 linuxkpi_alloc_skb(size_t size, gfp_t gfp) 89 { 90 struct sk_buff *skb; 91 size_t len; 92 93 len = sizeof(*skb) + size + sizeof(struct skb_shared_info); 94 /* 95 * Using our own type here not backing my kmalloc. 96 * We assume no one calls kfree directly on the skb. 97 */ 98 #ifdef __LP64__ 99 if (__predict_true(linuxkpi_skb_memlimit == 0)) { 100 skb = malloc(len, M_LKPISKB, linux_check_m_flags(gfp) | M_ZERO); 101 } else { 102 vm_paddr_t high; 103 104 switch (linuxkpi_skb_memlimit) { 105 case 2: 106 high = (0xfffffffff); /* 1<<36 really. */ 107 break; 108 case 1: 109 default: 110 high = (0xffffffff); /* 1<<32 really. */ 111 break; 112 } 113 len = roundup_pow_of_two(len); 114 skb = contigmalloc(len, M_LKPISKB, 115 linux_check_m_flags(gfp) | M_ZERO, 0, high, PAGE_SIZE, 0); 116 } 117 #else 118 skb = malloc(len, M_LKPISKB, linux_check_m_flags(gfp) | M_ZERO); 119 #endif 120 if (skb == NULL) 121 return (skb); 122 skb->_alloc_len = len; 123 skb->truesize = size; 124 125 skb->head = skb->data = skb->tail = (uint8_t *)(skb+1); 126 skb->end = skb->head + size; 127 128 skb->prev = skb->next = skb; 129 130 skb->shinfo = (struct skb_shared_info *)(skb->end); 131 132 SKB_TRACE_FMT(skb, "data %p size %zu", (skb) ? skb->data : NULL, size); 133 return (skb); 134 } 135 136 struct sk_buff * 137 linuxkpi_dev_alloc_skb(size_t size, gfp_t gfp) 138 { 139 struct sk_buff *skb; 140 size_t len; 141 142 len = size + NET_SKB_PAD; 143 skb = linuxkpi_alloc_skb(len, gfp); 144 145 if (skb != NULL) 146 skb_reserve(skb, NET_SKB_PAD); 147 148 SKB_TRACE_FMT(skb, "data %p size %zu len %zu", 149 (skb) ? skb->data : NULL, size, len); 150 return (skb); 151 } 152 153 struct sk_buff * 154 linuxkpi_build_skb(void *data, size_t fragsz) 155 { 156 struct sk_buff *skb; 157 158 if (data == NULL || fragsz == 0) 159 return (NULL); 160 161 /* Just allocate a skb without data area. */ 162 skb = linuxkpi_alloc_skb(0, GFP_KERNEL); 163 if (skb == NULL) 164 return (NULL); 165 166 skb->_flags |= _SKB_FLAGS_SKBEXTFRAG; 167 skb->truesize = fragsz; 168 skb->head = skb->data = data; 169 skb_reset_tail_pointer(skb); /* XXX is that correct? */ 170 skb->end = (void *)((uintptr_t)skb->head + fragsz); 171 172 return (skb); 173 } 174 175 struct sk_buff * 176 linuxkpi_skb_copy(struct sk_buff *skb, gfp_t gfp) 177 { 178 struct sk_buff *new; 179 struct skb_shared_info *shinfo; 180 size_t len; 181 unsigned int headroom; 182 183 /* Full buffer size + any fragments. */ 184 len = skb->end - skb->head + skb->data_len; 185 186 new = linuxkpi_alloc_skb(len, gfp); 187 if (new == NULL) 188 return (NULL); 189 190 headroom = skb_headroom(skb); 191 /* Fixup head and end. */ 192 skb_reserve(new, headroom); /* data and tail move headroom forward. */ 193 skb_put(new, skb->len); /* tail and len get adjusted */ 194 195 /* Copy data. */ 196 memcpy(new->head, skb->data - headroom, headroom + skb->len); 197 198 /* Deal with fragments. */ 199 shinfo = skb->shinfo; 200 if (shinfo->nr_frags > 0) { 201 printf("%s:%d: NOT YET SUPPORTED; missing %d frags\n", 202 __func__, __LINE__, shinfo->nr_frags); 203 SKB_TODO(); 204 } 205 206 /* Deal with header fields. */ 207 memcpy(new->cb, skb->cb, sizeof(skb->cb)); 208 SKB_IMPROVE("more header fields to copy?"); 209 210 return (new); 211 } 212 213 void 214 linuxkpi_kfree_skb(struct sk_buff *skb) 215 { 216 struct skb_shared_info *shinfo; 217 uint16_t fragno, count; 218 219 SKB_TRACE(skb); 220 if (skb == NULL) 221 return; 222 223 /* 224 * XXX TODO this will go away once we have skb backed by mbuf. 225 * currently we allow the mbuf to stay around and use a private 226 * free function to allow secondary resources to be freed along. 227 */ 228 if (skb->m != NULL) { 229 void *m; 230 231 m = skb->m; 232 skb->m = NULL; 233 234 KASSERT(skb->m_free_func != NULL, ("%s: skb %p has m %p but no " 235 "m_free_func %p\n", __func__, skb, m, skb->m_free_func)); 236 skb->m_free_func(m); 237 } 238 KASSERT(skb->m == NULL, 239 ("%s: skb %p m %p != NULL\n", __func__, skb, skb->m)); 240 241 shinfo = skb->shinfo; 242 for (count = fragno = 0; 243 count < shinfo->nr_frags && fragno < nitems(shinfo->frags); 244 fragno++) { 245 246 if (shinfo->frags[fragno].page != NULL) { 247 struct page *p; 248 249 p = shinfo->frags[fragno].page; 250 shinfo->frags[fragno].size = 0; 251 shinfo->frags[fragno].offset = 0; 252 shinfo->frags[fragno].page = NULL; 253 __free_page(p); 254 count++; 255 } 256 } 257 258 if ((skb->_flags & _SKB_FLAGS_SKBEXTFRAG) != 0) { 259 void *p; 260 261 p = skb->head; 262 skb_free_frag(p); 263 } 264 265 #ifdef __LP64__ 266 if (__predict_true(linuxkpi_skb_memlimit == 0)) 267 free(skb, M_LKPISKB); 268 else 269 contigfree(skb, skb->_alloc_len, M_LKPISKB); 270 #else 271 free(skb, M_LKPISKB); 272 #endif 273 } 274 275 #ifdef DDB 276 DB_SHOW_COMMAND(skb, db_show_skb) 277 { 278 struct sk_buff *skb; 279 int i; 280 281 if (!have_addr) { 282 db_printf("usage: show skb <addr>\n"); 283 return; 284 } 285 286 skb = (struct sk_buff *)addr; 287 288 db_printf("skb %p\n", skb); 289 db_printf("\tnext %p prev %p\n", skb->next, skb->prev); 290 db_printf("\tlist %p\n", &skb->list); 291 db_printf("\t_alloc_len %u len %u data_len %u truesize %u mac_len %u\n", 292 skb->_alloc_len, skb->len, skb->data_len, skb->truesize, 293 skb->mac_len); 294 db_printf("\tcsum %#06x l3hdroff %u l4hdroff %u priority %u qmap %u\n", 295 skb->csum, skb->l3hdroff, skb->l4hdroff, skb->priority, skb->qmap); 296 db_printf("\tpkt_type %d dev %p sk %p\n", 297 skb->pkt_type, skb->dev, skb->sk); 298 db_printf("\tcsum_offset %d csum_start %d ip_summed %d protocol %d\n", 299 skb->csum_offset, skb->csum_start, skb->ip_summed, skb->protocol); 300 db_printf("\t_flags %#06x\n", skb->_flags); /* XXX-BZ print names? */ 301 db_printf("\thead %p data %p tail %p end %p\n", 302 skb->head, skb->data, skb->tail, skb->end); 303 db_printf("\tshinfo %p m %p m_free_func %p\n", 304 skb->shinfo, skb->m, skb->m_free_func); 305 306 if (skb->shinfo != NULL) { 307 struct skb_shared_info *shinfo; 308 309 shinfo = skb->shinfo; 310 db_printf("\t\tgso_type %d gso_size %u nr_frags %u\n", 311 shinfo->gso_type, shinfo->gso_size, shinfo->nr_frags); 312 for (i = 0; i < nitems(shinfo->frags); i++) { 313 struct skb_frag *frag; 314 315 frag = &shinfo->frags[i]; 316 if (frag == NULL || frag->page == NULL) 317 continue; 318 db_printf("\t\t\tfrag %p fragno %d page %p %p " 319 "offset %ju size %zu\n", 320 frag, i, frag->page, linux_page_address(frag->page), 321 (uintmax_t)frag->offset, frag->size); 322 } 323 } 324 db_printf("\tcb[] %p {", skb->cb); 325 for (i = 0; i < nitems(skb->cb); i++) { 326 db_printf("%#04x%s", 327 skb->cb[i], (i < (nitems(skb->cb)-1)) ? ", " : ""); 328 } 329 db_printf("}\n"); 330 331 db_printf("\t__scratch[0] %p\n", skb->__scratch); 332 }; 333 #endif 334