7431 ZFS Channel Programs

Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Reviewed by: George Wilson <george.wilson@delphix.com>
Reviewed by: John Kennedy <john.kennedy@delphix.com>
Reviewed by: Dan Kimmel <dan.kimmel@delphix.com>
Approved by: Garrett D'Amore <garrett@damore.org>

1 files changed, 205 insertions, 1 deletions

diff --git a/usr/src/cmd/zfs/zfs_main.c b/usr/src/cmd/zfs/zfs_main.c
index e34a40a474..4f52949fba 100644
--- a/usr/src/cmd/zfs/zfs_main.c
+++ b/usr/src/cmd/zfs/zfs_main.c
@@ -21,7 +21,7 @@
 
 /*
  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
- * Copyright (c) 2011, 2015 by Delphix. All rights reserved.
+ * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
  * Copyright 2012 Milan Jurik. All rights reserved.
  * Copyright (c) 2012, Joyent, Inc. All rights reserved.
  * Copyright (c) 2011-2012 Pawel Jakub Dawidek. All rights reserved.
@@ -50,6 +50,7 @@
 #include <grp.h>
 #include <pwd.h>
 #include <signal.h>
+#include <sys/debug.h>
 #include <sys/list.h>
 #include <sys/mkdev.h>
 #include <sys/mntent.h>
@@ -106,6 +107,7 @@ static int zfs_do_holds(int argc, char **argv);
 static int zfs_do_release(int argc, char **argv);
 static int zfs_do_diff(int argc, char **argv);
 static int zfs_do_bookmark(int argc, char **argv);
+static int zfs_do_channel_program(int argc, char **argv);
 
 /*
  * Enable a reasonable set of defaults for libumem debugging on DEBUG builds.
@@ -153,6 +155,7 @@ typedef enum {
 	HELP_RELEASE,
 	HELP_DIFF,
 	HELP_BOOKMARK,
+	HELP_CHANNEL_PROGRAM,
 } zfs_help_t;
 
 typedef struct zfs_command {
@@ -180,6 +183,7 @@ static zfs_command_t command_table[] = {
 	{ "promote",	zfs_do_promote,		HELP_PROMOTE		},
 	{ "rename",	zfs_do_rename,		HELP_RENAME		},
 	{ "bookmark",	zfs_do_bookmark,	HELP_BOOKMARK		},
+	{ "program",    zfs_do_channel_program, HELP_CHANNEL_PROGRAM    },
 	{ NULL },
 	{ "list",	zfs_do_list,		HELP_LIST		},
 	{ NULL },
@@ -324,6 +328,10 @@ get_usage(zfs_help_t idx)
 		    "[snapshot|filesystem]\n"));
 	case HELP_BOOKMARK:
 		return (gettext("\tbookmark <snapshot> <bookmark>\n"));
+	case HELP_CHANNEL_PROGRAM:
+		return (gettext("\tprogram [-t <instruction limit>] "
+		    "[-m <memory limit (b)>] <pool> <program file> "
+		    "[lua args...]\n"));
 	}
 
 	abort();
@@ -352,6 +360,18 @@ safe_malloc(size_t size)
 	return (data);
 }
 
+void *
+safe_realloc(void *data, size_t size)
+{
+	void *newp;
+	if ((newp = realloc(data, size)) == NULL) {
+		free(data);
+		nomem();
+	}
+
+	return (newp);
+}
+
 static char *
 safe_strdup(char *str)
 {
@@ -6979,6 +6999,190 @@ usage:
 	return (-1);
 }
 
+static int
+zfs_do_channel_program(int argc, char **argv)
+{
+	int ret, fd;
+	char c;
+	char *progbuf, *filename, *poolname;
+	size_t progsize, progread;
+	nvlist_t *outnvl;
+	uint64_t instrlimit = ZCP_DEFAULT_INSTRLIMIT;
+	uint64_t memlimit = ZCP_DEFAULT_MEMLIMIT;
+	zpool_handle_t *zhp;
+
+	/* check options */
+	while (-1 !=
+	    (c = getopt(argc, argv, "t:(instr-limit)m:(memory-limit)"))) {
+		switch (c) {
+		case 't':
+		case 'm': {
+			uint64_t arg;
+			char *endp;
+
+			errno = 0;
+			arg = strtoull(optarg, &endp, 0);
+			if (errno != 0 || *endp != '\0') {
+				(void) fprintf(stderr, gettext(
+				    "invalid argument "
+				    "'%s': expected integer\n"), optarg);
+				goto usage;
+			}
+
+			if (c == 't') {
+				if (arg > ZCP_MAX_INSTRLIMIT || arg == 0) {
+					(void) fprintf(stderr, gettext(
+					    "Invalid instruction limit: "
+					    "%s\n"), optarg);
+					return (1);
+				} else {
+					instrlimit = arg;
+				}
+			} else {
+				ASSERT3U(c, ==, 'm');
+				if (arg > ZCP_MAX_MEMLIMIT || arg == 0) {
+					(void) fprintf(stderr, gettext(
+					    "Invalid memory limit: "
+					    "%s\n"), optarg);
+					return (1);
+				} else {
+					memlimit = arg;
+				}
+			}
+			break;
+		}
+		case '?':
+			(void) fprintf(stderr, gettext("invalid option '%c'\n"),
+			    optopt);
+			goto usage;
+		}
+	}
+
+	argc -= optind;
+	argv += optind;
+
+	if (argc < 2) {
+		(void) fprintf(stderr,
+		    gettext("invalid number of arguments\n"));
+		goto usage;
+	}
+
+	poolname = argv[0];
+	filename = argv[1];
+	if (strcmp(filename, "-") == 0) {
+		fd = 0;
+		filename = "standard input";
+	} else if ((fd = open(filename, O_RDONLY)) < 0) {
+		(void) fprintf(stderr, gettext("cannot open '%s': %s\n"),
+		    filename, strerror(errno));
+		return (1);
+	}
+
+	if ((zhp = zpool_open(g_zfs, poolname)) == NULL) {
+		(void) fprintf(stderr, gettext("cannot open pool '%s'"),
+		    poolname);
+		return (1);
+	}
+	zpool_close(zhp);
+
+	/*
+	 * Read in the channel program, expanding the program buffer as
+	 * necessary.
+	 */
+	progread = 0;
+	progsize = 1024;
+	progbuf = safe_malloc(progsize);
+	do {
+		ret = read(fd, progbuf + progread, progsize - progread);
+		progread += ret;
+		if (progread == progsize && ret > 0) {
+			progsize *= 2;
+			progbuf = safe_realloc(progbuf, progsize);
+		}
+	} while (ret > 0);
+
+	if (fd != 0)
+		(void) close(fd);
+	if (ret < 0) {
+		free(progbuf);
+		(void) fprintf(stderr,
+		    gettext("cannot read '%s': %s\n"),
+		    filename, strerror(errno));
+		return (1);
+	}
+	progbuf[progread] = '\0';
+
+	/*
+	 * Any remaining arguments are passed as arguments to the lua script as
+	 * a string array:
+	 * {
+	 *	"argv" -> [ "arg 1", ... "arg n" ],
+	 * }
+	 */
+	nvlist_t *argnvl = fnvlist_alloc();
+	fnvlist_add_string_array(argnvl, ZCP_ARG_CLIARGV, argv + 2, argc - 2);
+
+	ret = lzc_channel_program(poolname, progbuf, instrlimit, memlimit,
+	    argnvl, &outnvl);
+
+	if (ret != 0) {
+		/*
+		 * On error, report the error message handed back by lua if one
+		 * exists.  Otherwise, generate an appropriate error message,
+		 * falling back on strerror() for an unexpected return code.
+		 */
+		char *errstring = NULL;
+		if (nvlist_exists(outnvl, ZCP_RET_ERROR)) {
+			(void) nvlist_lookup_string(outnvl,
+			    ZCP_RET_ERROR, &errstring);
+			if (errstring == NULL)
+				errstring = strerror(ret);
+		} else {
+			switch (ret) {
+			case EINVAL:
+				errstring =
+				    "Invalid instruction or memory limit.";
+				break;
+			case ENOMEM:
+				errstring = "Return value too large.";
+				break;
+			case ENOSPC:
+				errstring = "Memory limit exhausted.";
+				break;
+			case ETIME:
+				errstring = "Timed out.";
+				break;
+			case EPERM:
+				errstring = "Permission denied. Channel "
+				    "programs must be run as root.";
+				break;
+			default:
+				errstring = strerror(ret);
+			}
+		}
+		(void) fprintf(stderr,
+		    gettext("Channel program execution failed:\n%s\n"),
+		    errstring);
+	} else {
+		(void) printf("Channel program fully executed ");
+		if (nvlist_empty(outnvl)) {
+			(void) printf("with no return value.\n");
+		} else {
+			(void) printf("with return value:\n");
+			dump_nvlist(outnvl, 4);
+		}
+	}
+
+	free(progbuf);
+	fnvlist_free(outnvl);
+	fnvlist_free(argnvl);
+	return (ret != 0);
+
+usage:
+	usage(B_FALSE);
+	return (-1);
+}
+
 int
 main(int argc, char **argv)
 {