nbd-trdump.c

   1 /*
   2  * nbd-trdump.c
   3  *
   4  * Takes an nbd transaction log file on stdin and translates it into something
   5  * comprehensible
   6  */
   7
   8 #include <stdlib.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sys/time.h>
  12 #include <sys/types.h>
  13 #include <stdint.h>
  14 #include <unistd.h>
  15 #include "config.h"
  16 /* We don't want to do syslog output in this program */
  17 #undef ISSERVER
  18 #include "cliserv.h"
  19 #include "nbd.h"
  20
  21 static inline void doread(int f, void *buf, size_t len) {
  22         ssize_t res;
  23
  24         while(len>0) {
  25                 if((res=read(f, buf, len)) <=0) {
  26                         if (!res)
  27                                 exit(0);
  28                         perror ("Error reading transactions");
  29                         exit(1);
  30                 }
  31                 len-=res;
  32                 buf+=res;
  33         }
  34 }
  35
  36 int main(int argc, char**argv) {
  37         struct nbd_request req;
  38         struct nbd_reply rep;
  39         uint32_t magic;
  40         uint64_t handle;
  41         uint32_t error;
  42         uint32_t command;
  43         uint32_t len;
  44         uint64_t offset;
  45         char * ctext;
  46         int readfd = 0; /* stdin */
  47
  48         if(argc > 1) {
  49                 int retval=0;
  50                 if(strcmp(argv[1], "--help") && strcmp(argv[1], "-h")) {
  51                         printf("E: unknown option %s.\n", argv[1]);
  52                         retval=1;
  53                 }
  54                 printf("This is nbd-trdump, part of nbd %s.\n", PACKAGE_VERSION);
  55                 printf("Use: %s < transactionlog\n", argv[0]);
  56                 return retval;
  57         }
  58
  59         while (1) {
  60                 /* Read a request or reply from the transaction file */
  61                 doread(readfd, &magic, sizeof(magic));
  62                 magic = ntohl(magic);
  63                 switch (magic) {
  64                 case NBD_REQUEST_MAGIC:
  65                         doread(readfd, sizeof(magic)+(char *)(&req), sizeof(struct nbd_request)-sizeof(magic));
  66                         handle = ntohll(*((long long int *)(req.handle)));
  67                         offset = ntohll(req.from);
  68                         len = ntohl(req.len);
  69                         command = ntohl(req.type);
  70
  71                         switch (command & NBD_CMD_MASK_COMMAND) {
  72                         case NBD_CMD_READ:
  73                                 ctext="NBD_CMD_READ";
  74                                 break;
  75                         case NBD_CMD_WRITE:
  76                                 ctext="NBD_CMD_WRITE";
  77                                 break;
  78                         case NBD_CMD_DISC:
  79                                 ctext="NBD_CMD_DISC";
  80                                 break;
  81                         case NBD_CMD_FLUSH:
  82                                 ctext="NBD_CMD_FLUSH";
  83                                 break;
  84                         default:
  85                                 ctext="UNKNOWN";
  86                                 break;
  87                         }
  88                         printf("> H=%016llx C=0x%08x (%13s+%4s) O=%016llx L=%08x\n",
  89                                (long long unsigned int) handle,
  90                                command,
  91                                ctext,
  92                                (command & NBD_CMD_FLAG_FUA)?"FUA":"NONE",
  93                                (long long unsigned int) offset,
  94                                len);
  95
  96                         break;
  97                 case NBD_REPLY_MAGIC:
  98                         doread(readfd, sizeof(magic)+(char *)(&rep), sizeof(struct nbd_reply)-sizeof(magic));
  99                         handle = ntohll(*((long long int *)(rep.handle)));
 100                         error = ntohl(rep.error);
 101
 102                         printf("< H=%016llx E=0x%08x\n",
 103                                (long long unsigned int) handle,
 104                                error);
 105                         break;
 106
 107                 default:
 108                         printf("? Unknown transaction type %08x\n",magic);
 109                         break;
 110                 }
 111
 112         }
 113         /* never reached */
 114         return 0;
 115 }