From: Wouter Verhelst Date: Sat, 24 Jul 2010 19:07:00 +0000 (+0200) Subject: Improve structure X-Git-Url: http://git.alex.org.uk Improve structure - Use getopt_long_only() to implement option parsing. This probably makes use of small C libraries harder, but that wasn't very much possible to begin with, anyway. - Deprecate bs= and timeout= options in favour of new --block-size and --timeout options. - Compartmentalize a bit more. Yes, the compiler will optimize that away in some cases, but what do I care, I don't need to write assembler code. Documentation update to follow. --- diff --git a/nbd-client.c b/nbd-client.c index 7aceb3e..35f5d8d 100644 --- a/nbd-client.c +++ b/nbd-client.c @@ -34,6 +34,7 @@ #include #include #include +#include #ifndef __GNUC__ #error I need GCC to work @@ -223,10 +224,44 @@ void finish_sock(int sock, int nbd, int swap) { mlockall(MCL_CURRENT | MCL_FUTURE); } +void usage(void) { + fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION); + fprintf(stderr, "Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-sdp] [-persist] [-nofork]\n"); + fprintf(stderr, "Or : nbd-client -d nbd_device\n"); + fprintf(stderr, "Or : nbd-client -c nbd_device\n"); + fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n"); + fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */ + fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n"); + fprintf(stderr, "blocksizes other than 1024 without patches\n"); +} + +void disconnect(char* device) { + int nbd = open(device, O_RDWR); + if (nbd < 0) + err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded."); + printf("Disconnecting: que, "); + if (ioctl(nbd, NBD_CLEAR_QUE)< 0) + err("Ioctl failed: %m\n"); + printf("disconnect, "); +#ifdef NBD_DISCONNECT + if (ioctl(nbd, NBD_DISCONNECT)<0) + err("Ioctl failed: %m\n"); + printf("sock, "); +#else + fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" ); + exit(1); +#endif + if (ioctl(nbd, NBD_CLEAR_SOCK)<0) + err("Ioctl failed: %m\n"); + printf("done\n"); +} + int main(int argc, char *argv[]) { - int port, sock, nbd; + int port=0; + int sock, nbd; int blocksize=1024; - char *hostname, *nbddev; + char *hostname=NULL; + char *nbddev=NULL; int swap=0; int cont=0; int timeout=0; @@ -234,105 +269,105 @@ int main(int argc, char *argv[]) { int nofork=0; u64 size64; u32 flags; - int i; + int i, c; + int nonspecial=0; + struct option long_options[] = { + { "block-size", required_argument, NULL, 'b' }, + { "check", required_argument, NULL, 'c' }, + { "disconnect", required_argument, NULL, 'd' }, + { "help", no_argument, NULL, 'h' }, + { "nofork", no_argument, NULL, 'n' }, + { "persist", no_argument, NULL, 'p' }, + { "sdp", no_argument, NULL, 'S' }, + { "swap", no_argument, NULL, 's' }, + { "timeout", required_argument, NULL, 't' }, + }; logging(); - if (argc < 3) { - errmsg: - fprintf(stderr, "nbd-client version %s\n", PACKAGE_VERSION); - fprintf(stderr, "Usage: nbd-client [bs=blocksize] [timeout=sec] host port nbd_device [-swap] [-persist] [-nofork]\n"); - fprintf(stderr, "Or : nbd-client -d nbd_device\n"); - fprintf(stderr, "Or : nbd-client -c nbd_device\n"); - fprintf(stderr, "Default value for blocksize is 1024 (recommended for ethernet)\n"); - fprintf(stderr, "Allowed values for blocksize are 512,1024,2048,4096\n"); /* will be checked in kernel :) */ - fprintf(stderr, "Note, that kernel 2.4.2 and older ones do not work correctly with\n"); - fprintf(stderr, "blocksizes other than 1024 without patches\n"); - return 1; - } - - ++argv; --argc; /* skip programname */ - - if (strcmp(argv[0], "-d")==0) { - nbd = open(argv[1], O_RDWR); - if (nbd < 0) - err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded."); - printf("Disconnecting: que, "); - if (ioctl(nbd, NBD_CLEAR_QUE)< 0) - err("Ioctl failed: %m\n"); - printf("disconnect, "); -#ifdef NBD_DISCONNECT - if (ioctl(nbd, NBD_DISCONNECT)<0) - err("Ioctl failed: %m\n"); - printf("sock, "); -#else - fprintf(stderr, "Can't disconnect: I was not compiled with disconnect support!\n" ); - exit(1); -#endif - if (ioctl(nbd, NBD_CLEAR_SOCK)<0) - err("Ioctl failed: %m\n"); - printf("done\n"); - return 0; - } - if(strcmp(argv[0], "-c")==0) { - return check_conn(argv[1], 1); - } - - if (strncmp(argv[0], "bs=", 3)==0) { - blocksize=atoi(argv[0]+3); - ++argv; --argc; /* skip blocksize */ + while((c=getopt_long_only(argc, argv, "-b:c:d:hnpSst:", long_options, NULL))>=0) { + switch(c) { + case 1: + // non-option argument + if(strchr(optarg, '=')) { + // old-style 'bs=' or 'timeout=' + // argument + fprintf(stderr, "WARNING: old-style command-line argument encountered. This is deprecated.\n"); + if(!strncmp(optarg, "bs=", 3)) { + optarg+=3; + goto blocksize; + } + if(!strncmp(optarg, "timeout=", 8)) { + optarg+=8; + goto timeout; + } + fprintf(stderr, "ERROR: unknown option %s encountered\n", optarg); + exit(EXIT_FAILURE); + } + switch(nonspecial++) { + case 0: + // host + hostname=optarg; + break; + case 1: + // port + port = strtol(optarg, NULL, 0); + break; + case 2: + // device + nbddev = optarg; + break; + default: + fprintf(stderr, "ERROR: too many non-option arguments specified\n"); + exit(EXIT_FAILURE); + } + break; + case 'b': + blocksize: + blocksize=(int)strtol(optarg, NULL, 0); + break; + case 'c': + check_conn(optarg, 1); + exit(EXIT_SUCCESS); + case 'd': + disconnect(optarg); + exit(EXIT_SUCCESS); + case 'h': + usage(); + exit(EXIT_SUCCESS); + case 'n': + nofork=1; + break; + case 'p': + cont=1; + break; + case 's': + swap=1; + break; + case 'S': + sdp=1; + break; + case 't': + timeout: + timeout=strtol(optarg, NULL, 0); + break; + default: + fprintf(stderr, "E: option eaten by 42 mice\n"); + exit(EXIT_FAILURE); + } } - if (strncmp(argv[0], "timeout=", 8)==0) { - timeout=atoi(argv[0]+8); - ++argv; --argc; /* skip timeout */ + if(!port || !hostname || !nbddev) { + usage(); + exit(EXIT_FAILURE); } - - if (argc==0) goto errmsg; - hostname=argv[0]; - ++argv; --argc; /* skip hostname */ - - if (argc==0) goto errmsg; - port = atoi(argv[0]); - ++argv; --argc; /* skip port */ - if (argc==0) goto errmsg; - nbddev = argv[0]; nbd = open(nbddev, O_RDWR); if (nbd < 0) err("Cannot open NBD: %m\nPlease ensure the 'nbd' module is loaded."); ++argv; --argc; /* skip device */ - if (argc>4) goto errmsg; - for(i=0; i<4; i++) { - if (argc) { - if(strncmp(argv[0], "-swap", 5)==0) { - swap=1; - ++argv;--argc; - } - } - if (argc) { - if(strncmp(argv[0], "-persist", 8)==0) { - cont=1; - ++argv;--argc; - } - } - if (argc) { - if(strncmp(argv[0], "-sdp", 4)==0) { - sdp=1; - ++argv;--argc; - } - } - if (argc) { - if(strncmp(argv[0], "-nofork", 7)==0) { - nofork=1; - ++argv;--argc; - } - } - } - if(argc) goto errmsg; sock = opennet(hostname, port, sdp); - argv=NULL; argc=0; /* don't use it later suddenly */ negotiate(sock, &size64, &flags); setsizes(nbd, size64, blocksize, flags);