1 /* $NetBSD: shmif_pcapin.c,v 1.1 2024/09/02 05:14:45 ozaki-r Exp $ */ 2 3 /*- 4 * Copyright (c) 2017-2018 Internet Initiative Japan Inc. 5 * Copyright (c) 2010 Antti Kantee. 6 * All Rights Reserved. 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 ``AS IS'' AND ANY EXPRESS 18 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * 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 OR 23 * 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 30 #include <rump/rumpuser_port.h> 31 32 #ifndef lint 33 __RCSID("$NetBSD: shmif_pcapin.c,v 1.1 2024/09/02 05:14:45 ozaki-r Exp $"); 34 #endif /* !lint */ 35 36 #include <stddef.h> 37 #include <sys/types.h> 38 #include <sys/mman.h> 39 #include <sys/stat.h> 40 #include <sys/atomic.h> 41 #include <sys/bswap.h> 42 43 #include <assert.h> 44 #include <err.h> 45 #include <fcntl.h> 46 #include <inttypes.h> 47 #include <pcap.h> 48 #include <stdbool.h> 49 #include <stdio.h> 50 #include <stdlib.h> 51 #include <string.h> 52 #include <unistd.h> 53 54 #include "shmifvar.h" 55 56 __dead static void 57 usage(void) 58 { 59 60 #ifndef HAVE_GETPROGNAME 61 #define getprogname() "shmif_pcapin" 62 #endif 63 64 fprintf(stderr, "usage: %s pcap-file-path bus-path\n", getprogname()); 65 exit(1); 66 } 67 68 /* 69 * The BUFSIZE come from shmif_dumpbus.c because there're not any experiences to 70 * make a decision about best size. 71 */ 72 #define BUFSIZE 64*1024 73 74 /* 75 * dowakeup, shmif_lockbus and shmif_unlockbus copy from 76 * sys/rump/net/lib/libshimif/if_shmem.c. So if you have to understood locking 77 * mechanism, you also see that. 78 */ 79 static int 80 dowakeup(int memfd) 81 { 82 struct iovec iov; 83 uint32_t ver = SHMIF_VERSION; 84 85 iov.iov_base = &ver; 86 iov.iov_len = sizeof(ver); 87 88 if (lseek(memfd, IFMEM_WAKEUP, SEEK_SET) == IFMEM_WAKEUP) 89 return writev(memfd, &iov, 1); 90 else 91 return -1; 92 } 93 94 /* 95 * This locking needs work and will misbehave severely if: 96 * 1) the backing memory has to be paged in 97 * 2) some lockholder exits while holding the lock 98 */ 99 static void 100 shmif_lockbus(struct shmif_mem *busmem) 101 { 102 int i = 0; 103 104 while (__predict_false(atomic_cas_32(&busmem->shm_lock, 105 LOCK_UNLOCKED, LOCK_LOCKED) == LOCK_LOCKED)) { 106 if (__predict_false(++i > LOCK_COOLDOWN)) { 107 usleep(1000); 108 i = 0; 109 } 110 continue; 111 } 112 membar_enter(); 113 } 114 115 static void 116 shmif_unlockbus(struct shmif_mem *busmem) 117 { 118 unsigned int old __diagused; 119 120 membar_exit(); 121 old = atomic_swap_32(&busmem->shm_lock, LOCK_UNLOCKED); 122 assert(old == LOCK_LOCKED); 123 } 124 125 126 int 127 main(int argc, char *argv[]) 128 { 129 struct stat sb; 130 void *busmem; 131 struct shmif_mem *bmem; 132 int fd; 133 const u_char *pkt; 134 char *buf; 135 char pcap_errbuf[PCAP_ERRBUF_SIZE]; 136 pcap_t *pcap; 137 struct pcap_pkthdr pcaphdr; 138 139 argc -= optind; 140 argv += optind; 141 142 if (argc != 2) 143 usage(); 144 145 buf = malloc(BUFSIZE); 146 if (buf == NULL) 147 err(EXIT_FAILURE, "malloc"); 148 149 fd = open(argv[1], O_RDWR); 150 if (fd == -1) 151 err(EXIT_FAILURE, "open bus"); 152 153 if (fstat(fd, &sb) == -1) 154 err(EXIT_FAILURE, "stat"); 155 156 busmem = mmap(NULL, sb.st_size, PROT_WRITE|PROT_READ, 157 MAP_FILE|MAP_SHARED, fd, 0); 158 if (busmem == MAP_FAILED) 159 err(EXIT_FAILURE, "mmap"); 160 bmem = busmem; 161 162 if (bmem->shm_magic != SHMIF_MAGIC) 163 errx(EXIT_FAILURE, "%s not a shmif bus", argv[1]); 164 165 /* 166 * if bmem->shm_version is 0, it indicates to not write any packets 167 * by anyone. 168 */ 169 if (bmem->shm_version != SHMIF_VERSION && bmem->shm_version != 0) 170 errx(EXIT_FAILURE, "bus version %d, program %d", 171 bmem->shm_version, SHMIF_VERSION); 172 173 fprintf(stdout, "bus version %d, lock: %d, generation: %" PRIu64 174 ", firstoff: 0x%04x, lastoff: 0x%04x\n", bmem->shm_version, 175 bmem->shm_lock, bmem->shm_gen, bmem->shm_first, bmem->shm_last); 176 177 pcap = pcap_open_offline(argv[0], pcap_errbuf); 178 if (pcap == NULL) 179 err(EXIT_FAILURE, "cannot open pcap file: %s", pcap_errbuf); 180 181 while ((pkt = pcap_next(pcap, &pcaphdr))) { 182 struct shmif_pkthdr sp; 183 uint32_t dataoff; 184 struct timeval tv; 185 bool wrap; 186 187 gettimeofday(&tv, NULL); 188 sp.sp_len = pcaphdr.len; 189 sp.sp_sec = tv.tv_sec; 190 sp.sp_usec = tv.tv_usec; 191 memcpy(buf, pkt, pcaphdr.len); 192 193 shmif_lockbus(bmem); 194 195 bmem->shm_last = shmif_nextpktoff(bmem, bmem->shm_last); 196 wrap = false; 197 198 dataoff = shmif_buswrite(bmem, bmem->shm_last, &sp, 199 sizeof(sp), &wrap); 200 dataoff = shmif_buswrite(bmem, dataoff, buf, pcaphdr.len, &wrap); 201 202 if (wrap) 203 bmem->shm_gen++; 204 205 shmif_unlockbus(bmem); 206 } 207 208 if (dowakeup(fd) == -1) 209 errx(EXIT_FAILURE, "writev for wakeup"); 210 211 return 0; 212 } 213