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         while (1) {
  47                 /* Read a request or reply from the transaction file */
  48                 doread(readfd, &magic, sizeof(magic));
  49                 magic = ntohl(magic);
  50                 switch (magic) {
  51                 case NBD_REQUEST_MAGIC:
  52                         doread(readfd, sizeof(magic)+(char *)(&req), sizeof(struct nbd_request)-sizeof(magic));
  53                         handle = ntohll(*((long long int *)(req.handle)));
  54                         offset = ntohll(req.from);
  55                         len = ntohl(req.len);
  56                         command = ntohl(req.type);
  57
  58                         switch (command & NBD_CMD_MASK_COMMAND) {
  59                         case NBD_CMD_READ:
  60                                 ctext="NBD_CMD_READ";
  61                                 break;
  62                         case NBD_CMD_WRITE:
  63                                 ctext="NBD_CMD_WRITE";
  64                                 break;
  65                         case NBD_CMD_DISC:
  66                                 ctext="NBD_CMD_DISC";
  67                                 break;
  68                         case NBD_CMD_FLUSH:
  69                                 ctext="NBD_CMD_FLUSH";
  70                                 break;
  71                         default:
  72                                 ctext="UNKNOWN";
  73                                 break;
  74                         }
  75                         printf("> H=%016llx C=0x%08x (%13s+%4s) O=%016llx L=%08x\n",
  76                                (long long unsigned int) handle,
  77                                command,
  78                                ctext,
  79                                (command & NBD_CMD_FLAG_FUA)?"FUA":"NONE",
  80                                (long long unsigned int) offset,
  81                                len);
  82
  83                         break;
  84                 case NBD_REPLY_MAGIC:
  85                         doread(readfd, sizeof(magic)+(char *)(&rep), sizeof(struct nbd_reply)-sizeof(magic));
  86                         handle = ntohll(*((long long int *)(rep.handle)));
  87                         error = ntohl(rep.error);
  88
  89                         printf("< H=%016llx E=0x%08x\n",
  90                                (long long unsigned int) handle,
  91                                error);
  92                         break;
  93
  94                 default:
  95                         printf("? Unknown transaction type %08x\n",magic);
  96                         break;
  97                 }
  98
  99         }
 100         /* never reached */
 101         return 0;
 102 }