1 /*- 2 * Copyright (c) 2001 3 * Jeff Wheelhouse (jdw@wwwi.com) 4 * 5 * This code was originally developed by Jeff Wheelhouse (jdw@wwwi.com). 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. Redistribution of source code must retail 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 JEFF WHEELHOUSE ``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. IN 19 * NO EVENT SHALL JEFF WHEELHOUSE BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING BUT NOT 21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 22 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 23 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 24 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 25 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 * 27 * $Id: clog.c,v 1.3 2001/10/02 18:51:26 jdw Exp $ 28 * $DragonFly: src/usr.sbin/clog/clog.c,v 1.2 2004/12/18 22:48:03 swildner Exp $ 29 */ 30 31 32 #include <assert.h> 33 #include <errno.h> 34 #include <fcntl.h> 35 #include <poll.h> 36 #include <sched.h> 37 #include <signal.h> 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 43 #include <sys/mman.h> 44 #include <sys/stat.h> 45 #include <sys/uio.h> 46 47 48 #include "clog.h" 49 50 51 /* 52 * The BUFFER_SIZE value is just used to allocate a buffer full of NULLs 53 * so that a new logfile can be extended to its full size. 54 * 55 * Compiling with -pedantic complains when the buffer array is declared 56 * if I declare this as a const instead of a #define. 57 */ 58 #define BUFFER_SIZE 16384 59 60 void init_log __P((const char *lname, size_t size)); 61 void read_log __P((const char *lname, int optf)); 62 void usage __P((void)); 63 64 const char *pname; 65 66 int main(int argc, char **argv) { 67 int ch; 68 int init = 0; 69 int size = 0; 70 int optf = 0; 71 72 pname = argv[0]; 73 74 while ((ch = getopt(argc, argv, "fis:")) != -1) 75 switch(ch) { 76 case 'i': 77 init = 1; 78 break; 79 case 's': 80 size = atol(optarg); 81 if (size==0) usage(); 82 break; 83 case 'f': 84 optf = 1; 85 } 86 87 if ((size>0)&&(init==0)) { 88 fprintf(stderr,"%s: WARNING: -s argument ignored without -i.\n",pname); 89 size = 0; 90 } 91 if (argv[optind]==NULL) { 92 fprintf(stderr,"%s: ERROR: log_file argument must be specified.\n",pname); 93 usage(); 94 } 95 if ((init==1)&&(size==0)) { 96 fprintf(stderr,"%s: ERROR: -i argument requires -s.\n",pname); 97 usage(); 98 } 99 if ((init==1)&&(optf==1)) { 100 fprintf(stderr,"%s: ERROR: flags -f and -i are incompatible.\n",pname); 101 usage(); 102 } 103 104 if (init==1) init_log(argv[optind],size); 105 /* if (optf==1) follow_log(artv[optind]); */ 106 read_log(argv[optind],optf); 107 108 return 0; 109 } 110 111 112 void usage() { 113 fprintf(stderr,"usage: %s [-i -s log_size] [ -f ] log_file\n",pname); 114 exit(1); 115 } 116 117 118 void read_log(const char *lname, int optf) { 119 int fd; 120 struct stat sb; 121 struct clog_footer *pcf; 122 char *pbuffer; 123 struct iovec iov[2]; 124 int iovcnt = 0; 125 uint32_t start = 0; 126 uint32_t next; 127 struct pollfd pfd; 128 129 pfd.fd = -1; 130 131 fd = open(lname,O_RDONLY); 132 if (fd==-1) { 133 fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno)); 134 exit(11); 135 } 136 137 if (fstat(fd,&sb)==-1) { 138 fprintf(stderr,"%s: ERROR: could not stat %s (%s)\n",pname,lname,strerror(errno)); 139 exit(13); 140 } 141 pbuffer = mmap(NULL,sb.st_size,PROT_READ,MAP_SHARED,fd,0); 142 if (pbuffer==NULL) { 143 fprintf(stderr,"%s: ERROR: could not mmap %s body (%s)\n",pname,lname,strerror(errno)); 144 exit(14); 145 } 146 pcf = (struct clog_footer*)(pbuffer + sb.st_size - sizeof(struct clog_footer)); 147 148 if (pcf->cf_wrap==1) start = pcf->cf_next + 1; 149 while(1) { 150 while(pcf->cf_lock==1) sched_yield(); 151 next = pcf->cf_next; 152 iovcnt = 0; 153 if (start>next) { 154 iov[iovcnt].iov_base = pbuffer + start; 155 iov[iovcnt++].iov_len = pcf->cf_max - start; 156 start = 0; 157 } 158 iov[iovcnt].iov_base = pbuffer + start; 159 iov[iovcnt++].iov_len = next - start; 160 if (writev(1,iov,iovcnt)==-1) { 161 fprintf(stderr,"%s: ERROR: could not write output (%s)\n",pname,strerror(errno)); 162 exit(15); 163 } 164 start = next; 165 if (optf==0) break; 166 if (poll(&pfd,1,50)==-1) { 167 fprintf(stderr,"%s: ERROR: could not poll (%s)\n",pname,strerror(errno)); 168 exit(16); 169 } 170 } 171 172 munmap(pbuffer,sb.st_size); 173 close(fd); 174 175 exit(0); 176 } 177 178 179 void init_log(const char *lname, size_t size) { 180 int fd; 181 size_t fill = size; 182 char buffer[BUFFER_SIZE]; 183 struct clog_footer cf; 184 185 memcpy(&cf.cf_magic,MAGIC_CONST,4); 186 cf.cf_max = size - sizeof(struct clog_footer); 187 188 memset(buffer,0,BUFFER_SIZE); 189 190 fd = open(lname,O_RDWR|O_CREAT,0666); 191 if (fd==-1) { 192 fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno)); 193 exit(2); 194 } 195 if (ftruncate(fd,(off_t)0)==-1) { 196 fprintf(stderr,"%s: ERROR: could not truncate %s (%s)\n",pname,lname,strerror(errno)); 197 exit(3); 198 } 199 200 while(fill>BUFFER_SIZE) { 201 if (write(fd,buffer,BUFFER_SIZE)==-1){ 202 fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno)); 203 exit(4); 204 } 205 fill -= BUFFER_SIZE; 206 } 207 assert(fill<=BUFFER_SIZE); 208 if (fill>0) { 209 if (write(fd,buffer,fill)==-1) { 210 fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno)); 211 exit(5); 212 } 213 } 214 if (lseek(fd,-(off_t)(sizeof(struct clog_footer)),SEEK_END)==-1) { 215 fprintf(stderr,"%s: ERROR: could not seek in %s (%s)\n",pname,lname,strerror(errno)); 216 exit(6); 217 } 218 if (write(fd,&cf,sizeof(cf))==-1) { 219 fprintf(stderr,"%s: ERROR: could not write magic in %s (%s)\n",pname,lname,strerror(errno)); 220 exit(7); 221 } 222 close(fd); 223 exit(0); 224 } 225 226 227