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 */ 29 30 31 #include <assert.h> 32 #include <errno.h> 33 #include <fcntl.h> 34 #include <poll.h> 35 #include <signal.h> 36 #include <stdio.h> 37 #include <stdlib.h> 38 #include <string.h> 39 #include <unistd.h> 40 41 #include <sys/mman.h> 42 #include <sys/sched.h> 43 #include <sys/stat.h> 44 #include <sys/uio.h> 45 46 47 #include "clog.h" 48 49 50 /* 51 * The BUFFER_SIZE value is just used to allocate a buffer full of NULLs 52 * so that a new logfile can be extended to its full size. 53 * 54 * Compiling with -pedantic complains when the buffer array is declared 55 * if I declare this as a const instead of a #define. 56 */ 57 #define BUFFER_SIZE 16384 58 59 static void init_log(const char *lname, size_t size) __dead2; 60 static void read_log(const char *lname, int optf) __dead2; 61 static void usage(void) __dead2; 62 63 static const char *pname; 64 65 int 66 main(int argc, char **argv) 67 { 68 int ch; 69 int init = 0; 70 int size = 0; 71 int optf = 0; 72 73 pname = argv[0]; 74 75 while ((ch = getopt(argc, argv, "fis:")) != -1) 76 switch(ch) { 77 case 'i': 78 init = 1; 79 break; 80 case 's': 81 size = atol(optarg); 82 if (size==0) usage(); 83 break; 84 case 'f': 85 optf = 1; 86 } 87 88 if ((size>0)&&(init==0)) { 89 fprintf(stderr,"%s: WARNING: -s argument ignored without -i.\n",pname); 90 size = 0; 91 } 92 if (argv[optind]==NULL) { 93 fprintf(stderr,"%s: ERROR: log_file argument must be specified.\n",pname); 94 usage(); 95 } 96 if ((init==1)&&(size==0)) { 97 fprintf(stderr,"%s: ERROR: -i argument requires -s.\n",pname); 98 usage(); 99 } 100 if ((init==1)&&(optf==1)) { 101 fprintf(stderr,"%s: ERROR: flags -f and -i are incompatible.\n",pname); 102 usage(); 103 } 104 105 if (init==1) init_log(argv[optind],size); 106 /* if (optf==1) follow_log(artv[optind]); */ 107 read_log(argv[optind],optf); 108 109 return 0; 110 } 111 112 113 static void 114 usage(void) 115 { 116 fprintf(stderr,"usage: %s [-i -s log_size] [ -f ] log_file\n",pname); 117 exit(1); 118 } 119 120 121 static void 122 read_log(const char *lname, int optf) 123 { 124 int fd; 125 struct stat sb; 126 struct clog_footer *pcf; 127 char *pbuffer; 128 struct iovec iov[2]; 129 int iovcnt = 0; 130 uint32_t start = 0; 131 uint32_t next; 132 struct pollfd pfd; 133 134 pfd.fd = -1; 135 136 fd = open(lname,O_RDONLY); 137 if (fd==-1) { 138 fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno)); 139 exit(11); 140 } 141 142 if (fstat(fd,&sb)==-1) { 143 fprintf(stderr,"%s: ERROR: could not stat %s (%s)\n",pname,lname,strerror(errno)); 144 exit(13); 145 } 146 pbuffer = mmap(NULL,sb.st_size,PROT_READ,MAP_SHARED,fd,0); 147 if (pbuffer==NULL) { 148 fprintf(stderr,"%s: ERROR: could not mmap %s body (%s)\n",pname,lname,strerror(errno)); 149 exit(14); 150 } 151 pcf = (struct clog_footer*)(pbuffer + sb.st_size - sizeof(struct clog_footer)); 152 153 if (pcf->cf_wrap==1) start = pcf->cf_next + 1; 154 while(1) { 155 while(pcf->cf_lock==1) sched_yield(); 156 next = pcf->cf_next; 157 iovcnt = 0; 158 if (start>next) { 159 iov[iovcnt].iov_base = pbuffer + start; 160 iov[iovcnt++].iov_len = pcf->cf_max - start; 161 start = 0; 162 } 163 iov[iovcnt].iov_base = pbuffer + start; 164 iov[iovcnt++].iov_len = next - start; 165 if (writev(1,iov,iovcnt)==-1) { 166 fprintf(stderr,"%s: ERROR: could not write output (%s)\n",pname,strerror(errno)); 167 exit(15); 168 } 169 start = next; 170 if (optf==0) break; 171 if (poll(&pfd,1,50)==-1) { 172 fprintf(stderr,"%s: ERROR: could not poll (%s)\n",pname,strerror(errno)); 173 exit(16); 174 } 175 } 176 177 munmap(pbuffer,sb.st_size); 178 close(fd); 179 180 exit(0); 181 } 182 183 184 static void 185 init_log(const char *lname, size_t size) 186 { 187 int fd; 188 size_t fill = size; 189 char buffer[BUFFER_SIZE]; 190 struct clog_footer cf; 191 192 memcpy(&cf.cf_magic,MAGIC_CONST,4); 193 cf.cf_max = size - sizeof(struct clog_footer); 194 195 memset(buffer,0,BUFFER_SIZE); 196 197 fd = open(lname,O_RDWR|O_CREAT,0666); 198 if (fd==-1) { 199 fprintf(stderr,"%s: ERROR: could not open %s (%s)\n",pname,lname,strerror(errno)); 200 exit(2); 201 } 202 if (ftruncate(fd,(off_t)0)==-1) { 203 fprintf(stderr,"%s: ERROR: could not truncate %s (%s)\n",pname,lname,strerror(errno)); 204 exit(3); 205 } 206 207 while(fill>BUFFER_SIZE) { 208 if (write(fd,buffer,BUFFER_SIZE)==-1){ 209 fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno)); 210 exit(4); 211 } 212 fill -= BUFFER_SIZE; 213 } 214 assert(fill<=BUFFER_SIZE); 215 if (fill>0) { 216 if (write(fd,buffer,fill)==-1) { 217 fprintf(stderr,"%s: ERROR: could not write %s (%s)\n",pname,lname,strerror(errno)); 218 exit(5); 219 } 220 } 221 if (lseek(fd,-(off_t)(sizeof(struct clog_footer)),SEEK_END)==-1) { 222 fprintf(stderr,"%s: ERROR: could not seek in %s (%s)\n",pname,lname,strerror(errno)); 223 exit(6); 224 } 225 if (write(fd,&cf,sizeof(cf))==-1) { 226 fprintf(stderr,"%s: ERROR: could not write magic in %s (%s)\n",pname,lname,strerror(errno)); 227 exit(7); 228 } 229 close(fd); 230 exit(0); 231 } 232