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 #include "cliserv.h"
  17 #include "nbd.h"
  18
  19 static inline void doread(int f, void *buf, size_t len) {
  20         ssize_t res;
  21
  22         while(len>0) {
  23                 if((res=read(f, buf, len)) <=0) {
  24                         if (!res)
  25                                 exit(0);
  26                         perror ("Error reading transactions");
  27                         exit(1);
  28                 }
  29                 len-=res;
  30                 buf+=res;
  31         }
  32 }
  33
  34 int main(int argc, char**argv) {
  35         struct nbd_request req;
  36         struct nbd_reply rep;
  37         uint32_t magic;
  38         uint64_t handle;
  39         uint32_t error;
  40         uint32_t command;
  41         uint32_t len;
  42         uint64_t offset;
  43         char * ctext;
  44         int readfd = 0; /* stdin */
  45
  46         if(argc > 1) {
  47                 int retval=0;
  48                 if(strcmp(argv[1], "--help") && strcmp(argv[1], "-h")) {
  49                         printf("E: unknown option %s.\n", argv[1]);
  50                         retval=1;
  51                 }
  52                 printf("This is nbd-trdump, part of nbd %s.\n", PACKAGE_VERSION);
  53                 printf("Use: %s < transactionlog\n", argv[0]);
  54                 return retval;
  55         }
  56
  57         while (1) {
  58                 /* Read a request or reply from the transaction file */
  59                 doread(readfd, &magic, sizeof(magic));
  60                 magic = ntohl(magic);
  61                 switch (magic) {
  62                 case NBD_REQUEST_MAGIC:
  63                         doread(readfd, sizeof(magic)+(char *)(&req), sizeof(struct nbd_request)-sizeof(magic));
  64                         handle = ntohll(*((long long int *)(req.handle)));
  65                         offset = ntohll(req.from);
  66                         len = ntohl(req.len);
  67                         command = ntohl(req.type);
  68
  69                         switch (command & NBD_CMD_MASK_COMMAND) {
  70                         case NBD_CMD_READ:
  71                                 ctext="NBD_CMD_READ";
  72                                 break;
  73                         case NBD_CMD_WRITE:
  74                                 ctext="NBD_CMD_WRITE";
  75                                 break;
  76                         case NBD_CMD_DISC:
  77                                 ctext="NBD_CMD_DISC";
  78                                 break;
  79                         case NBD_CMD_FLUSH:
  80                                 ctext="NBD_CMD_FLUSH";
  81                                 break;
  82                         default:
  83                                 ctext="UNKNOWN";
  84                                 break;
  85                         }
  86                         printf("> H=%016llx C=0x%08x (%13s+%4s) O=%016llx L=%08x\n",
  87                                (long long unsigned int) handle,
  88                                command,
  89                                ctext,
  90                                (command & NBD_CMD_FLAG_FUA)?"FUA":"NONE",
  91                                (long long unsigned int) offset,
  92                                len);
  93
  94                         break;
  95                 case NBD_REPLY_MAGIC:
  96                         doread(readfd, sizeof(magic)+(char *)(&rep), sizeof(struct nbd_reply)-sizeof(magic));
  97                         handle = ntohll(*((long long int *)(rep.handle)));
  98                         error = ntohl(rep.error);
  99
 100                         printf("< H=%016llx E=0x%08x\n",
 101                                (long long unsigned int) handle,
 102                                error);
 103                         break;
 104
 105                 default:
 106                         printf("? Unknown transaction type %08x\n",magic);
 107                         break;
 108                 }
 109
 110         }
 111         /* never reached */
 112         return 0;
 113 }