The branch main has been updated by kevans: URL: https://cgit.FreeBSD.org/src/commit/?id=1d8590371049bb14a6410fa83cd03d9eca32f764
commit 1d8590371049bb14a6410fa83cd03d9eca32f764 Author: Kyle Evans <kev...@freebsd.org> AuthorDate: 2025-07-26 03:13:43 +0000 Commit: Kyle Evans <kev...@freebsd.org> CommitDate: 2025-07-26 03:13:43 +0000 jls: add a -c mode to check for a jail's existence This is intended to be primarily used in scripts that want to check if a jail exists before taking some action -- for instance, the jail(8) test cleanup functions that want to remove the jail if it still exists. Having a mode that limits its output for their usage is useful both for cleaner scripts and also to avoid masking real problems. Reviewed by: jamie Differential Revision: https://reviews.freebsd.org/D51541 --- usr.sbin/jls/jls.8 | 20 ++++++++++++++++++-- usr.sbin/jls/jls.c | 48 ++++++++++++++++++++++++++++++++++++++++++++---- 2 files changed, 62 insertions(+), 6 deletions(-) diff --git a/usr.sbin/jls/jls.8 b/usr.sbin/jls/jls.8 index f7a5eeb321ef..715033082963 100644 --- a/usr.sbin/jls/jls.8 +++ b/usr.sbin/jls/jls.8 @@ -23,7 +23,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd February 13, 2025 +.Dd July 25, 2025 .Dt JLS 8 .Os .Sh NAME @@ -35,6 +35,10 @@ .Op Fl dhNnqsv .Op Fl j Ar jail .Op Ar parameter ... +.Nm +.Fl c +.Op Fl d +.Fl j Ar jail .Sh DESCRIPTION The .Nm @@ -54,11 +58,21 @@ for a description of some core parameters. If no .Ar parameters or any of the options -.Fl hns +.Fl chns are given, the following four columns will be printed: jail identifier (jid), IP address (ip4.addr), hostname (host.hostname), and path (path). .Pp +When the +.Fl c +option is used, +.Nm +will not emit any output except for usage errors. +This mode is intended solely to check for a single jail's existence, and it does +not accept any +.Ar parameter +or print-option flags. +.Pp The following options are available: .Bl -tag -width indent .It Fl -libxo @@ -68,6 +82,8 @@ in a selection of different human and machine readable formats. See .Xr xo_options 7 for details on command line arguments. +.It Fl c +Only check for the jail's existence. .It Fl d List .Va dying diff --git a/usr.sbin/jls/jls.c b/usr.sbin/jls/jls.c index a1d1716713aa..4f697a5bb382 100644 --- a/usr.sbin/jls/jls.c +++ b/usr.sbin/jls/jls.c @@ -37,6 +37,7 @@ #include <arpa/inet.h> #include <netinet/in.h> +#include <assert.h> #include <ctype.h> #include <errno.h> #include <jail.h> @@ -59,6 +60,7 @@ #define PRINT_SKIP 0x10 #define PRINT_VERBOSE 0x20 #define PRINT_JAIL_NAME 0x40 +#define PRINT_EXISTS 0x80 static struct jailparam *params; static int *param_parent; @@ -81,6 +83,14 @@ static void quoted_print(int pflags, char *name, char *value); static void emit_ip_addr_list(int af_family, const char *list_name, struct jailparam *param); +static void +usage(void) +{ + xo_errx(1, + "usage: jls [-dhNnqv] [-j jail] [param ...]\n" + " jls -c [-d] -j jail"); +} + int main(int argc, char **argv) { @@ -94,12 +104,15 @@ main(int argc, char **argv) xo_set_version(JLS_XO_VERSION); jname = NULL; pflags = jflags = jid = 0; - while ((c = getopt(argc, argv, "adj:hNnqsv")) >= 0) + while ((c = getopt(argc, argv, "acdj:hNnqsv")) >= 0) switch (c) { case 'a': case 'd': jflags |= JAIL_DYING; break; + case 'c': + pflags |= PRINT_EXISTS; + break; case 'j': jid = strtoul(optarg, &ep, 10); if (!jid || *ep) { @@ -130,7 +143,7 @@ main(int argc, char **argv) PRINT_VERBOSE; break; default: - xo_errx(1, "usage: jls [-dhNnqv] [-j jail] [param ...]"); + usage(); } #ifdef INET6 @@ -144,7 +157,24 @@ main(int argc, char **argv) argv += optind; /* Add the parameters to print. */ - if (argc == 0) { + if ((pflags & PRINT_EXISTS) != 0) { + if ((pflags & ~PRINT_EXISTS) != 0) { + xo_warnx("-c is incompatible with other print options"); + usage(); + } else if (argc != 0) { + xo_warnx("-c does not accept non-option arguments"); + usage(); + } else if (jid == 0 && jname == NULL) { + xo_warnx("-j jail to check must be provided for -c"); + usage(); + } + + /* + * Force libxo to be silent, as well -- we're only wanting our + * exit status. + */ + xo_set_style(NULL, XO_STYLE_TEXT); + } else if (argc == 0) { if (pflags & (PRINT_HEADER | PRINT_NAMEVAL)) add_param("all", NULL, (size_t)0, NULL, JP_USER); else if (pflags & PRINT_VERBOSE) { @@ -239,9 +269,17 @@ main(int argc, char **argv) xo_open_list("jail"); /* Fetch the jail(s) and print the parameters. */ if (jid != 0 || jname != NULL) { - if (print_jail(pflags, jflags) < 0) + if (print_jail(pflags, jflags) < 0) { + /* + * We omit errors from existential issues if we're just + * doing a -c check that the jail exists. + */ + if (pflags & PRINT_EXISTS) + exit(1); xo_errx(1, "%s", jail_errmsg); + } } else { + assert((pflags & PRINT_EXISTS) == 0); for (lastjid = 0; (lastjid = print_jail(pflags, jflags)) >= 0; ) ; @@ -392,6 +430,8 @@ print_jail(int pflags, int jflags) jid = jailparam_get(params, nparams, jflags); if (jid < 0) return jid; + else if (pflags & PRINT_EXISTS) + return 0; xo_open_instance("jail");