From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cyril Hrubis Date: Fri, 9 Aug 2019 14:27:41 +0200 Subject: [LTP] [RFC PATCH 1/1] capability: Introduce capability API In-Reply-To: <20190808153825.18363-2-rpalethorpe@suse.com> References: <20190808153825.18363-1-rpalethorpe@suse.com> <20190808153825.18363-2-rpalethorpe@suse.com> Message-ID: <20190809122741.GC32115@rei.lan> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ltp@lists.linux.it Hi! > include/tst_capability.h | 56 +++++++++++++++++++++++++++++ > include/tst_test.h | 6 ++++ > lib/tst_capability.c | 78 ++++++++++++++++++++++++++++++++++++++++ > lib/tst_test.c | 3 ++ > 4 files changed, 143 insertions(+) > create mode 100644 include/tst_capability.h > create mode 100644 lib/tst_capability.c This is missing a documentation in the test-writing-guidelines I do expect that you will add that later on. > diff --git a/include/tst_capability.h b/include/tst_capability.h > new file mode 100644 > index 000000000..6342b667e > --- /dev/null > +++ b/include/tst_capability.h > @@ -0,0 +1,56 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Copyright (c) 2019 Richard Palethorpe > + */ > +/** > + * @file tst_capability.h > + * > + * Limited capability operations without libcap. > + */ > + > +#include > + > +#include "lapi/syscalls.h" ^ What is this needed for here? > +#ifndef TST_CAPABILITY_H > +#define TST_CAPABILITY_H > + > +#ifndef CAP_SYS_ADMIN > +# define CAP_SYS_ADMIN 21 > +#endif > > +#ifndef CAP_TO_MASK > +# define CAP_TO_MASK(x) (1 << ((x) & 31)) > +#endif These bits should probably go to lapi/capability.h > +#define TST_DROP 1 > +#define TST_REQUIRE 1 << 1 Maybe these should be TST_CAP_DROP and TST_CAP_REQ > +#define TST_CAP(action, capability) {action, capability, #capability} > + > +struct tst_cap_user_header { > + uint32_t version; > + int pid; > +}; > + > +struct tst_cap_user_data { > + uint32_t effective; > + uint32_t permitted; > + uint32_t inheritable; > +}; This two should probably go to lapi as well. > +struct tst_cap { > + uint32_t action; > + uint32_t id; > + char *name; > +}; I wonder if we should build a table of capability names for translation just as we do errnos and signals instead of storing the name here. But I guess that unless we will need a function to translate capabilitities into strings on runtime this approach is simpler. > +int tst_capget(struct tst_cap_user_header *hdr, > + struct tst_cap_user_data *data); > +int tst_capset(struct tst_cap_user_header *hdr, > + const struct tst_cap_user_data *data); > + > +void tst_cap_action(struct tst_cap *cap); > +void tst_cap_setup(struct tst_cap *cap); > + > +#endif > diff --git a/include/tst_test.h b/include/tst_test.h > index cdeaf6ad0..84acf2c59 100644 > --- a/include/tst_test.h > +++ b/include/tst_test.h > @@ -36,6 +36,7 @@ > #include "tst_sys_conf.h" > #include "tst_coredump.h" > #include "tst_buffers.h" > +#include "tst_capability.h" > > /* > * Reports testcase result. > @@ -206,6 +207,11 @@ struct tst_test { > * NULL-terminated array to be allocated buffers. > */ > struct tst_buffers *bufs; > + > + /* > + * NULL-terminated array of capability settings > + */ > + struct tst_cap *caps; > }; > > /* > diff --git a/lib/tst_capability.c b/lib/tst_capability.c > new file mode 100644 > index 000000000..d229491ae > --- /dev/null > +++ b/lib/tst_capability.c > @@ -0,0 +1,78 @@ > +/* SPDX-License-Identifier: GPL-2.0-or-later */ > +/* > + * Copyright (c) 2019 Richard Palethorpe > + */ > + > +#define TST_NO_DEFAULT_MAIN > +#include "tst_test.h" > +#include "tst_capability.h" > + > +int tst_capget(struct tst_cap_user_header *hdr, > + struct tst_cap_user_data *data) > +{ > + return tst_syscall(__NR_capget, hdr, data); > +} > + > +int tst_capset(struct tst_cap_user_header *hdr, > + const struct tst_cap_user_data *data) > +{ > + return tst_syscall(__NR_capset, hdr, data); > +} > + > +void tst_cap_action(struct tst_cap *cap) > +{ > + struct tst_cap_user_header hdr = { > + .version = 0x20080522, > + .pid = tst_syscall(__NR_gettid), > + }; > + struct tst_cap_user_data cur = { 0 }; > + struct tst_cap_user_data new = { 0 }; > + uint32_t mask = CAP_TO_MASK(cap->id); > + uint32_t act = cap->action; > + > + if (tst_capget(&hdr, &cur)) > + tst_brk(TBROK | TTERRNO, "tst_capget()"); > + > + new = cur; > + > + switch (act) { > + case TST_DROP: > + if (cur.effective & mask) { > + tst_res(TINFO, "Dropping %s(%d)", > + cap->name, cap->id); > + new.effective &= ~mask; > + new.permitted &= ~mask; > + new.inheritable &= ~mask; > + } > + break; > + case TST_REQUIRE: > + if (cur.permitted ^ mask) { > + tst_brk(TCONF, "Need %s(%d)", > + cap->name, cap->id); > + } else if (cur.effective ^ mask) { > + tst_res(TINFO, "Permitting %s(%d)", > + cap->name, cap->id); > + new.effective |= mask; > + new.inheritable |= mask; > + } > + break; > + default: > + tst_brk(TBROK, "Unrecognised action %d", cap->action); > + } > + > + if (cur.effective != new.effective) { > + if (tst_capset(&hdr, &new)) > + tst_brk(TBROK | TERRNO, "tst_capset(%s)", cap->name); > + } else { > + tst_res(TINFO, "No capability changes needed"); > + } > +} > + > +void tst_cap_setup(struct tst_cap *caps) > +{ > + struct tst_cap *cap; > + > + for (cap = caps; cap->action; cap++) { > + tst_cap_action(cap); > + } No need for the curly braces here :-). > +} > diff --git a/lib/tst_test.c b/lib/tst_test.c > index 8dc71dbb3..62e54d071 100644 > --- a/lib/tst_test.c > +++ b/lib/tst_test.c > @@ -893,6 +893,9 @@ static void do_test_setup(void) > > if (main_pid != getpid()) > tst_brk(TBROK, "Runaway child in setup()!"); > + > + if (tst_test->caps) > + tst_cap_setup(tst_test->caps); > } Other than the minor things and missing docs this patch looks good to me. -- Cyril Hrubis chrubis@suse.cz