Move libcap use to (Linux) platform-specific code

The libcap code is Linux-specific so move it all below
the linux/ platform subdirectory.  As this feature has
custom command-line long options I provide a mechanism
whereby each platform can add custom long options that
augment the main htop options.  We'll make use this of
this with the pcp/ platform in due course to implement
the --host and --archive options there.

Related to https://github.com/htop-dev/htop/pull/536
This commit is contained in:
Nathan Scott 2021-03-17 14:29:40 +11:00
parent 57e0ce7b4f
commit 0ada9f325f
9 changed files with 220 additions and 164 deletions

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@ -77,4 +77,8 @@ static inline void Platform_getRelease(char** string) {
*string = Generic_uname();
}
static bool Platform_getLongOption(ATTR_UNUSED int opt, ATTR_UNUSED int argc, ATTR_UNUSED char** argv) {
return false;
}
#endif

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@ -67,4 +67,8 @@ static inline void Platform_getRelease(char** string) {
*string = Generic_uname();
}
static bool Platform_getLongOption(ATTR_UNUSED int opt, ATTR_UNUSED int argc, ATTR_UNUSED char** argv) {
return false;
}
#endif

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@ -72,4 +72,8 @@ static inline void Platform_getRelease(char** string) {
*string = Generic_uname();
}
static bool Platform_getLongOption(ATTR_UNUSED int opt, ATTR_UNUSED int argc, ATTR_UNUSED char** argv) {
return false;
}
#endif

172
htop.c
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@ -1,6 +1,7 @@
/*
htop - htop.c
(C) 2004-2011 Hisham H. Muhammad
(C) 2020-2021 htop dev team
Released under the GNU GPLv2, see the COPYING file
in the source distribution for its full text.
*/
@ -8,7 +9,6 @@ in the source distribution for its full text.
#include "config.h" // IWYU pragma: keep
#include <assert.h>
#include <errno.h>
#include <getopt.h>
#include <locale.h>
#include <stdbool.h>
@ -35,37 +35,28 @@ in the source distribution for its full text.
#include "UsersTable.h"
#include "XUtils.h"
#ifdef HAVE_LIBCAP
#include <sys/capability.h>
#ifndef PLATFORM_LONG_OPTIONS
#define PLATFORM_LONG_OPTIONS
#endif
#ifdef HAVE_LIBCAP
enum CapMode {
CAP_MODE_NONE,
CAP_MODE_BASIC,
CAP_MODE_STRICT
};
#ifndef PLATFORM_LONG_OPTIONS_USAGE
#define PLATFORM_LONG_OPTIONS_USAGE
#endif
static void printVersionFlag(void) {
fputs(PACKAGE " " VERSION "\n", stdout);
static void printVersionFlag(const char* name) {
fprintf(stdout, "%s " VERSION "\n", name);
}
static void printHelpFlag(void) {
fputs(PACKAGE " " VERSION "\n"
static void printHelpFlag(const char* name) {
fprintf(stdout, "%s " VERSION "\n"
COPYRIGHT "\n"
"Released under the GNU GPLv2.\n\n"
"-C --no-color Use a monochrome color scheme\n"
"-d --delay=DELAY Set the delay between updates, in tenths of seconds\n"
"-F --filter=FILTER Show only the commands matching the given filter\n"
"-h --help Print this help screen\n"
#ifdef HAVE_LIBCAP
" --drop-capabilities[=none|basic|strict] Drop Linux capabilities when running as root\n"
" none - do not drop any capabilities\n"
" basic (default) - drop all capabilities not needed by htop\n"
" strict - drop all capabilities except those needed for core functionality\n"
#endif
PLATFORM_LONG_OPTIONS_USAGE
"-H --highlight-changes[=DELAY] Highlight new and old processes\n"
"-M --no-mouse Disable the mouse\n"
"-p --pid=PID[,PID,PID...] Show only the given PIDs\n"
@ -76,9 +67,9 @@ static void printHelpFlag(void) {
"-V --version Print version info\n"
"\n"
"Long options may be passed with a single dash.\n\n"
"Press F1 inside " PACKAGE " for online help.\n"
"See 'man " PACKAGE "' for more information.\n",
stdout);
"Press F1 inside %s for online help.\n"
"See 'man %s' for more information.\n",
name, name, name);
}
// ----------------------------------------
@ -95,12 +86,9 @@ typedef struct CommandLineSettings_ {
bool allowUnicode;
bool highlightChanges;
int highlightDelaySecs;
#ifdef HAVE_LIBCAP
enum CapMode capabilitiesMode;
#endif
} CommandLineSettings;
static CommandLineSettings parseArguments(int argc, char** argv) {
static CommandLineSettings parseArguments(const char* program, int argc, char** argv) {
CommandLineSettings flags = {
.pidMatchList = NULL,
@ -114,9 +102,6 @@ static CommandLineSettings parseArguments(int argc, char** argv) {
.allowUnicode = true,
.highlightChanges = false,
.highlightDelaySecs = -1,
#ifdef HAVE_LIBCAP
.capabilitiesMode = CAP_MODE_BASIC,
#endif
};
const struct option long_opts[] =
@ -134,9 +119,7 @@ static CommandLineSettings parseArguments(int argc, char** argv) {
{"pid", required_argument, 0, 'p'},
{"filter", required_argument, 0, 'F'},
{"highlight-changes", optional_argument, 0, 'H'},
#ifdef HAVE_LIBCAP
{"drop-capabilities", optional_argument, 0, 128},
#endif
PLATFORM_LONG_OPTIONS
{0,0,0,0}
};
@ -146,10 +129,10 @@ static CommandLineSettings parseArguments(int argc, char** argv) {
if (opt == EOF) break;
switch (opt) {
case 'h':
printHelpFlag();
printHelpFlag(program);
exit(0);
case 'V':
printVersionFlag();
printVersionFlag(program);
exit(0);
case 's':
assert(optarg); /* please clang analyzer, cause optarg can be NULL in the 'u' case */
@ -218,7 +201,7 @@ static CommandLineSettings parseArguments(int argc, char** argv) {
char* saveptr;
const char* pid = strtok_r(argCopy, ",", &saveptr);
if(!flags.pidMatchList) {
if (!flags.pidMatchList) {
flags.pidMatchList = Hashtable_new(8, false);
}
@ -255,29 +238,11 @@ static CommandLineSettings parseArguments(int argc, char** argv) {
flags.highlightChanges = true;
break;
}
#ifdef HAVE_LIBCAP
case 128: {
const char* mode = optarg;
if (!mode && optind < argc && argv[optind] != NULL &&
(argv[optind][0] != '\0' && argv[optind][0] != '-')) {
mode = argv[optind++];
}
if (!mode || String_eq(mode, "basic")) {
flags.capabilitiesMode = CAP_MODE_BASIC;
} else if (String_eq(mode, "none")) {
flags.capabilitiesMode = CAP_MODE_NONE;
} else if (String_eq(mode, "strict")) {
flags.capabilitiesMode = CAP_MODE_STRICT;
} else {
fprintf(stderr, "Error: invalid capabilities mode \"%s\".\n", mode);
exit(1);
}
break;
}
#endif
default:
exit(1);
if (Platform_getLongOption(opt, argc, argv) == false)
exit(1);
break;
}
}
return flags;
@ -304,92 +269,6 @@ static void setCommFilter(State* state, char** commFilter) {
*commFilter = NULL;
}
#ifdef HAVE_LIBCAP
static int dropCapabilities(enum CapMode mode) {
if (mode == CAP_MODE_NONE)
return 0;
/* capabilities we keep to operate */
const cap_value_t keepcapsStrict[] = {
CAP_DAC_READ_SEARCH,
CAP_SYS_PTRACE,
};
const cap_value_t keepcapsBasic[] = {
CAP_DAC_READ_SEARCH, /* read non world-readable process files of other users, like /proc/[pid]/io */
CAP_KILL, /* send signals to processes of other users */
CAP_SYS_NICE, /* lower process nice value / change nice value for arbitrary processes */
CAP_SYS_PTRACE, /* read /proc/[pid]/exe */
#ifdef HAVE_DELAYACCT
CAP_NET_ADMIN, /* communicate over netlink socket for delay accounting */
#endif
};
const cap_value_t* const keepcaps = (mode == CAP_MODE_BASIC) ? keepcapsBasic : keepcapsStrict;
const size_t ncap = (mode == CAP_MODE_BASIC) ? ARRAYSIZE(keepcapsBasic) : ARRAYSIZE(keepcapsStrict);
cap_t caps = cap_init();
if (caps == NULL) {
fprintf(stderr, "Error: can not initialize capabilities: %s\n", strerror(errno));
return -1;
}
if (cap_clear(caps) < 0) {
fprintf(stderr, "Error: can not clear capabilities: %s\n", strerror(errno));
cap_free(caps);
return -1;
}
cap_t currCaps = cap_get_proc();
if (currCaps == NULL) {
fprintf(stderr, "Error: can not get current process capabilities: %s\n", strerror(errno));
cap_free(caps);
return -1;
}
for (size_t i = 0; i < ncap; i++) {
if (!CAP_IS_SUPPORTED(keepcaps[i]))
continue;
cap_flag_value_t current;
if (cap_get_flag(currCaps, keepcaps[i], CAP_PERMITTED, &current) < 0) {
fprintf(stderr, "Error: can not get current value of capability %d: %s\n", keepcaps[i], strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
if (current != CAP_SET)
continue;
if (cap_set_flag(caps, CAP_PERMITTED, 1, &keepcaps[i], CAP_SET) < 0) {
fprintf(stderr, "Error: can not set permitted capability %d: %s\n", keepcaps[i], strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &keepcaps[i], CAP_SET) < 0) {
fprintf(stderr, "Error: can not set effective capability %d: %s\n", keepcaps[i], strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
}
if (cap_set_proc(caps) < 0) {
fprintf(stderr, "Error: can not set process capabilities: %s\n", strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
cap_free(currCaps);
cap_free(caps);
return 0;
}
#endif
int main(int argc, char** argv) {
/* initialize locale */
@ -399,12 +278,7 @@ int main(int argc, char** argv) {
else
setlocale(LC_CTYPE, "");
CommandLineSettings flags = parseArguments(argc, argv);
#ifdef HAVE_LIBCAP
if (dropCapabilities(flags.capabilitiesMode) < 0)
exit(1);
#endif
CommandLineSettings flags = parseArguments(PACKAGE, argc, argv);
Platform_init();

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@ -12,6 +12,7 @@ in the source distribution for its full text.
#include <assert.h>
#include <ctype.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <math.h>
@ -61,11 +62,23 @@ in the source distribution for its full text.
#include "zfs/ZfsArcStats.h"
#include "zfs/ZfsCompressedArcMeter.h"
#ifdef HAVE_LIBCAP
#include <sys/capability.h>
#endif
#ifdef HAVE_SENSORS_SENSORS_H
#include "LibSensors.h"
#endif
#ifdef HAVE_LIBCAP
enum CapMode {
CAP_MODE_NONE,
CAP_MODE_BASIC,
CAP_MODE_STRICT
};
#endif
const ProcessField Platform_defaultFields[] = { PID, USER, PRIORITY, NICE, M_VIRT, M_RESIDENT, M_SHARE, STATE, PERCENT_CPU, PERCENT_MEM, TIME, COMM, 0 };
const SignalItem Platform_signals[] = {
@ -112,22 +125,9 @@ static time_t Platform_Battery_cacheTime;
static double Platform_Battery_cachePercent = NAN;
static ACPresence Platform_Battery_cacheIsOnAC;
void Platform_init(void) {
if (access(PROCDIR, R_OK) != 0) {
fprintf(stderr, "Error: could not read procfs (compiled to look in %s).\n", PROCDIR);
exit(1);
}
#ifdef HAVE_SENSORS_SENSORS_H
LibSensors_init(NULL);
#ifdef HAVE_LIBCAP
static enum CapMode Platform_capabilitiesMode = CAP_MODE_BASIC;
#endif
}
void Platform_done(void) {
#ifdef HAVE_SENSORS_SENSORS_H
LibSensors_cleanup();
#endif
}
static Htop_Reaction Platform_actionSetIOPriority(State* st) {
const LinuxProcess* p = (const LinuxProcess*) Panel_getSelected((Panel*)st->mainPanel);
@ -845,3 +845,146 @@ void Platform_getBattery(double* percent, ACPresence* isOnAC) {
Platform_Battery_cacheIsOnAC = *isOnAC;
Platform_Battery_cacheTime = now;
}
bool Platform_getLongOption(int opt, int argc, char** argv) {
#ifndef HAVE_LIBCAP
(void) argc;
(void) argv;
#endif
switch (opt) {
#ifdef HAVE_LIBCAP
case 128: {
const char* mode = optarg;
if (!mode && optind < argc && argv[optind] != NULL &&
(argv[optind][0] != '\0' && argv[optind][0] != '-')) {
mode = argv[optind++];
}
if (!mode || String_eq(mode, "basic")) {
Platform_capabilitiesMode = CAP_MODE_BASIC;
} else if (String_eq(mode, "none")) {
Platform_capabilitiesMode = CAP_MODE_NONE;
} else if (String_eq(mode, "strict")) {
Platform_capabilitiesMode = CAP_MODE_STRICT;
} else {
fprintf(stderr, "Error: invalid capabilities mode \"%s\".\n", mode);
exit(1);
}
break;
}
#endif
default:
break;
}
return false;
}
#ifdef HAVE_LIBCAP
static int dropCapabilities(enum CapMode mode) {
if (mode == CAP_MODE_NONE)
return 0;
/* capabilities we keep to operate */
const cap_value_t keepcapsStrict[] = {
CAP_DAC_READ_SEARCH,
CAP_SYS_PTRACE,
};
const cap_value_t keepcapsBasic[] = {
CAP_DAC_READ_SEARCH, /* read non world-readable process files of other users, like /proc/[pid]/io */
CAP_KILL, /* send signals to processes of other users */
CAP_SYS_NICE, /* lower process nice value / change nice value for arbitrary processes */
CAP_SYS_PTRACE, /* read /proc/[pid]/exe */
#ifdef HAVE_DELAYACCT
CAP_NET_ADMIN, /* communicate over netlink socket for delay accounting */
#endif
};
const cap_value_t* const keepcaps = (mode == CAP_MODE_BASIC) ? keepcapsBasic : keepcapsStrict;
const size_t ncap = (mode == CAP_MODE_BASIC) ? ARRAYSIZE(keepcapsBasic) : ARRAYSIZE(keepcapsStrict);
cap_t caps = cap_init();
if (caps == NULL) {
fprintf(stderr, "Error: can not initialize capabilities: %s\n", strerror(errno));
return -1;
}
if (cap_clear(caps) < 0) {
fprintf(stderr, "Error: can not clear capabilities: %s\n", strerror(errno));
cap_free(caps);
return -1;
}
cap_t currCaps = cap_get_proc();
if (currCaps == NULL) {
fprintf(stderr, "Error: can not get current process capabilities: %s\n", strerror(errno));
cap_free(caps);
return -1;
}
for (size_t i = 0; i < ncap; i++) {
if (!CAP_IS_SUPPORTED(keepcaps[i]))
continue;
cap_flag_value_t current;
if (cap_get_flag(currCaps, keepcaps[i], CAP_PERMITTED, &current) < 0) {
fprintf(stderr, "Error: can not get current value of capability %d: %s\n", keepcaps[i], strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
if (current != CAP_SET)
continue;
if (cap_set_flag(caps, CAP_PERMITTED, 1, &keepcaps[i], CAP_SET) < 0) {
fprintf(stderr, "Error: can not set permitted capability %d: %s\n", keepcaps[i], strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
if (cap_set_flag(caps, CAP_EFFECTIVE, 1, &keepcaps[i], CAP_SET) < 0) {
fprintf(stderr, "Error: can not set effective capability %d: %s\n", keepcaps[i], strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
}
if (cap_set_proc(caps) < 0) {
fprintf(stderr, "Error: can not set process capabilities: %s\n", strerror(errno));
cap_free(currCaps);
cap_free(caps);
return -1;
}
cap_free(currCaps);
cap_free(caps);
return 0;
}
#endif
void Platform_init(void) {
#ifdef HAVE_LIBCAP
if (dropCapabilities(Platform_capabilitiesMode) < 0)
exit(1);
#endif
if (access(PROCDIR, R_OK) != 0) {
fprintf(stderr, "Error: could not read procfs (compiled to look in %s).\n", PROCDIR);
exit(1);
}
#ifdef HAVE_SENSORS_SENSORS_H
LibSensors_init(NULL);
#endif
}
void Platform_done(void) {
#ifdef HAVE_SENSORS_SENSORS_H
LibSensors_cleanup();
#endif
}

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@ -27,6 +27,19 @@ in the source distribution for its full text.
#define PATH_MAX 4096
#endif
#ifdef HAVE_LIBCAP
#define PLATFORM_LONG_OPTIONS \
{"drop-capabilities", optional_argument, 0, 128},
#define PLATFORM_LONG_OPTIONS_USAGE \
" --drop-capabilities[=none|basic|strict] Drop Linux capabilities when running as root\n" \
" none - do not drop any capabilities\n" \
" basic (default) - drop all capabilities not needed by htop\n" \
" strict - drop all capabilities except those needed for core functionality\n"
#else
#define PLATFORM_LONG_OPTIONS
#define PLATFORM_LONG_OPTIONS_USAGE
#endif
extern const ProcessField Platform_defaultFields[];
@ -82,4 +95,6 @@ static inline void Platform_getRelease(char** string) {
*string = Generic_uname();
}
bool Platform_getLongOption(int opt, int argc, char** argv);
#endif

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@ -70,4 +70,8 @@ static inline void Platform_getRelease(char** string) {
*string = Generic_uname();
}
static bool Platform_getLongOption(ATTR_UNUSED int opt, ATTR_UNUSED int argc, ATTR_UNUSED char** argv) {
return false;
}
#endif

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@ -89,4 +89,8 @@ static inline void Platform_getRelease(char** string) {
*string = Generic_uname();
}
static bool Platform_getLongOption(ATTR_UNUSED int opt, ATTR_UNUSED int argc, ATTR_UNUSED char** argv) {
return false;
}
#endif

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@ -61,4 +61,8 @@ void Platform_getHostname(char* buffer, size_t size);
void Platform_getRelease(char** string);
static bool Platform_getLongOption(ATTR_UNUSED int opt, ATTR_UNUSED int argc, ATTR_UNUSED char** argv) {
return false;
}
#endif