granicus.if.org Git - strace/blob - capability.c

   1 /*
   2  * Copyright (c) 2000 Wichert Akkerman <wakkerma@debian.org>
   3  * Copyright (c) 2011 Denys Vlasenko <dvlasenk@redhat.com>
   4  * Copyright (c) 2005-2015 Dmitry V. Levin <ldv@altlinux.org>
   5  * Copyright (c) 2014-2018 The strace developers.
   6  * All rights reserved.
   7  *
   8  * SPDX-License-Identifier: LGPL-2.1-or-later
   9  */
  10
  11 #include "defs.h"
  12
  13 /* these constants are the same as in <linux/capability.h> */
  14 enum {
  15 #include "caps0.h"
  16 };
  17
  18 #include "xlat/cap_mask0.h"
  19
  20 /* these constants are CAP_TO_INDEX'ed constants from <linux/capability.h> */
  21 enum {
  22 #include "caps1.h"
  23 };
  24
  25 #include "xlat/cap_mask1.h"
  26
  27 /* these constants are the same as in <linux/capability.h> */
  28 enum {
  29         _LINUX_CAPABILITY_VERSION_1 = 0x19980330,
  30         _LINUX_CAPABILITY_VERSION_2 = 0x20071026,
  31         _LINUX_CAPABILITY_VERSION_3 = 0x20080522
  32 };
  33
  34 #include "xlat/cap_version.h"
  35
  36 struct user_cap_header_struct {
  37         uint32_t version;
  38         int pid;
  39 };
  40
  41 struct user_cap_data_struct {
  42         uint32_t effective;
  43         uint32_t permitted;
  44         uint32_t inheritable;
  45 };
  46
  47 static const struct user_cap_header_struct *
  48 get_cap_header(struct tcb *const tcp, const kernel_ulong_t addr)
  49 {
  50         static struct user_cap_header_struct header;
  51
  52         if (!addr || !verbose(tcp))
  53                 return NULL;
  54
  55         if (umove(tcp, addr, &header) < 0)
  56                 return NULL;
  57
  58         return &header;
  59 }
  60
  61 static void
  62 print_cap_header(struct tcb *const tcp, const kernel_ulong_t addr,
  63                  const struct user_cap_header_struct *const h)
  64 {
  65         if (!addr || !h) {
  66                 printaddr(addr);
  67                 return;
  68         }
  69
  70         tprints("{version=");
  71         printxval(cap_version, h->version,
  72                   "_LINUX_CAPABILITY_VERSION_???");
  73         tprintf(", pid=%d}", h->pid);
  74 }
  75
  76 static void
  77 print_cap_bits(const uint32_t lo, const uint32_t hi)
  78 {
  79         if (lo || !hi)
  80                 printflags(cap_mask0, lo, "CAP_???");
  81
  82         if (hi) {
  83                 if (lo)
  84                         tprints("|");
  85                 printflags(cap_mask1, hi, "CAP_???");
  86         }
  87 }
  88
  89 static void
  90 print_cap_data(struct tcb *const tcp, const kernel_ulong_t addr,
  91                const struct user_cap_header_struct *const h)
  92 {
  93         struct user_cap_data_struct data[2];
  94         unsigned int len;
  95
  96         if (!addr || !h) {
  97                 printaddr(addr);
  98                 return;
  99         }
 100
 101         if (_LINUX_CAPABILITY_VERSION_2 == h->version ||
 102             _LINUX_CAPABILITY_VERSION_3 == h->version)
 103                 len = 2;
 104         else
 105                 len = 1;
 106
 107         if (umoven_or_printaddr(tcp, addr, len * sizeof(data[0]), data))
 108                 return;
 109
 110         tprints("{effective=");
 111         print_cap_bits(data[0].effective, len > 1 ? data[1].effective : 0);
 112         tprints(", permitted=");
 113         print_cap_bits(data[0].permitted, len > 1 ? data[1].permitted : 0);
 114         tprints(", inheritable=");
 115         print_cap_bits(data[0].inheritable, len > 1 ? data[1].inheritable : 0);
 116         tprints("}");
 117 }
 118
 119 SYS_FUNC(capget)
 120 {
 121         const struct user_cap_header_struct *h;
 122
 123         if (entering(tcp)) {
 124                 h = get_cap_header(tcp, tcp->u_arg[0]);
 125                 print_cap_header(tcp, tcp->u_arg[0], h);
 126                 tprints(", ");
 127         } else {
 128                 h = syserror(tcp) ? NULL : get_cap_header(tcp, tcp->u_arg[0]);
 129                 print_cap_data(tcp, tcp->u_arg[1], h);
 130         }
 131         return 0;
 132 }
 133
 134 SYS_FUNC(capset)
 135 {
 136         const struct user_cap_header_struct *const h =
 137                 get_cap_header(tcp, tcp->u_arg[0]);
 138         print_cap_header(tcp, tcp->u_arg[0], h);
 139         tprints(", ");
 140         print_cap_data(tcp, tcp->u_arg[1], h);
 141
 142         return RVAL_DECODED;
 143 }