nbd-trdump.c

Go to the documentation of this file.

/*
 * nbd-trdump.c
 *
 * Takes an nbd transaction log file on stdin and translates it into something
 * comprehensible
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>
#include <sys/types.h>
#include <stdint.h>
#include <unistd.h>
#include "config.h"
/* We don't want to do syslog output in this program */
#undef ISSERVER
#include "cliserv.h"
#include "nbd.h"

static inline void doread(int f, void *buf, size_t len) {
        ssize_t res;

        while(len>0) {
                if((res=read(f, buf, len)) <=0) {
                        if (!res)
                                exit(0);
                        perror ("Error reading transactions");
                        exit(1);
                }
                len-=res;
                buf+=res;
        }
}

int main(int argc, char**argv) {
        struct nbd_request req;
        struct nbd_reply rep;
        uint32_t magic;
        uint64_t handle;
        uint32_t error;
        uint32_t command;
        uint32_t len;
        uint64_t offset;
        char * ctext;
        int readfd = 0; /* stdin */

        if(argc > 1) {
                int retval=0;
                if(strcmp(argv[1], "--help") && strcmp(argv[1], "-h")) {
                        printf("E: unknown option %s.\n", argv[1]);
                        retval=1;
                }
                printf("This is nbd-trdump, part of nbd %s.\n", PACKAGE_VERSION);
                printf("Use: %s < transactionlog\n", argv[0]);
                return retval;
        }

        while (1) {
                /* Read a request or reply from the transaction file */
                doread(readfd, &magic, sizeof(magic));
                magic = ntohl(magic);
                switch (magic) {
                case NBD_REQUEST_MAGIC:
                        doread(readfd, sizeof(magic)+(char *)(&req), sizeof(struct nbd_request)-sizeof(magic));
                        handle = ntohll(*((long long int *)(req.handle)));
                        offset = ntohll(req.from);
                        len = ntohl(req.len);
                        command = ntohl(req.type);
                        
                        switch (command & NBD_CMD_MASK_COMMAND) {
                        case NBD_CMD_READ:
                                ctext="NBD_CMD_READ";
                                break;
                        case NBD_CMD_WRITE:
                                ctext="NBD_CMD_WRITE";
                                break;
                        case NBD_CMD_DISC:
                                ctext="NBD_CMD_DISC";
                                break;
                        case NBD_CMD_FLUSH:
                                ctext="NBD_CMD_FLUSH";
                                break;
                        default:
                                ctext="UNKNOWN";
                                break;
                        }
                        printf("> H=%016llx C=0x%08x (%13s+%4s) O=%016llx L=%08x\n",
                               (long long unsigned int) handle,
                               command,
                               ctext,
                               (command & NBD_CMD_FLAG_FUA)?"FUA":"NONE",
                               (long long unsigned int) offset,
                               len);
                        
                        break;
                case NBD_REPLY_MAGIC:
                        doread(readfd, sizeof(magic)+(char *)(&rep), sizeof(struct nbd_reply)-sizeof(magic));
                        handle = ntohll(*((long long int *)(rep.handle)));
                        error = ntohl(rep.error);
                        
                        printf("< H=%016llx E=0x%08x\n",
                               (long long unsigned int) handle,
                               error);
                        break;
                        
                default:
                        printf("? Unknown transaction type %08x\n",magic);
                        break;
                }
                
        }
        /* never reached */
        return 0;
}