analyze: add 'capability' verb for dumping all known and unknown caps

src/analyze/analyze.c

@@ -21,6 +21,8 @@
 #include "bus-map-properties.h"
 #include "bus-unit-util.h"
 #include "calendarspec.h"
+#include "cap-list.h"
+#include "capability-util.h"
 #include "conf-files.h"
 #include "copy.h"
 #include "def.h"
@@ -1592,6 +1594,51 @@ static int dump_exit_status(int argc, char *argv[], void *userdata) {
         return table_print(table, NULL);
 }
 
+static int dump_capabilities(int argc, char *argv[], void *userdata) {
+        _cleanup_(table_unrefp) Table *table = NULL;
+        unsigned last_cap;
+        int r;
+
+        table = table_new("name", "number");
+        if (!table)
+                return log_oom();
+
+        (void) table_set_align_percent(table, table_get_cell(table, 0, 1), 100);
+
+        /* Determine the maximum of the last cap known by the kernel and by us */
+        last_cap = MAX((unsigned) CAP_LAST_CAP, cap_last_cap());
+
+        if (strv_isempty(strv_skip(argv, 1)))
+                for (unsigned c = 0; c <= last_cap; c++) {
+                        r = table_add_many(table,
+                                           TABLE_STRING, capability_to_name(c) ?: "cap_???",
+                                           TABLE_UINT, c);
+                        if (r < 0)
+                                return table_log_add_error(r);
+                }
+        else {
+                for (int i = 1; i < argc; i++) {
+                        int c;
+
+                        c = capability_from_name(argv[i]);
+                        if (c < 0 || (unsigned) c > last_cap)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Capability \"%s\" not known.", argv[i]);
+
+                        r = table_add_many(table,
+                                           TABLE_STRING, capability_to_name(c) ?: "cap_???",
+                                           TABLE_UINT, (unsigned) c);
+                        if (r < 0)
+                                return table_log_add_error(r);
+                }
+
+                (void) table_set_sort(table, (size_t) 1, (size_t) -1);
+        }
+
+        (void) pager_open(arg_pager_flags);
+
+        return table_print(table, NULL);
+}
+
 #if HAVE_SECCOMP
 
 static int load_kernel_syscalls(Set **ret) {
@@ -2126,6 +2173,7 @@ static int help(int argc, char *argv[], void *userdata) {
                "  unit-files               List files and symlinks for units\n"
                "  unit-paths               List load directories for units\n"
                "  exit-status [STATUS...]  List exit status definitions\n"
+               "  capability [CAP...]      List capability definitions\n"
                "  syscall-filter [NAME...] Print list of syscalls in seccomp filter\n"
                "  condition CONDITION...   Evaluate conditions and asserts\n"
                "  verify FILE...           Check unit files for correctness\n"
@@ -2363,6 +2411,7 @@ static int run(int argc, char *argv[]) {
                 { "unit-paths",        1,        1,        0,            dump_unit_paths        },
                 { "exit-status",       VERB_ANY, VERB_ANY, 0,            dump_exit_status       },
                 { "syscall-filter",    VERB_ANY, VERB_ANY, 0,            dump_syscall_filters   },
+                { "capability",        VERB_ANY, VERB_ANY, 0,            dump_capabilities      },
                 { "condition",         2,        VERB_ANY, 0,            do_condition           },
                 { "verify",            2,        VERB_ANY, 0,            do_verify              },
                 { "calendar",          2,        VERB_ANY, 0,            test_calendar          },