// Functions used for implementing the ulimit builtin.
#include "config.h" // IWYU pragma: keep
#include <sys/resource.h>
#include <cerrno>
#include <cstddef>
#include "builtin.h"
#include "common.h"
#include "fallback.h" // IWYU pragma: keep
#include "io.h"
#include "wgetopt.h"
#include "wutil.h" // IWYU pragma: keep
class parser_t;
/// Struct describing a resource limit.
struct resource_t {
int resource; // resource ID
const wchar_t *desc; // description of resource
wchar_t switch_char; // switch used on commandline to specify resource
int multiplier; // the implicit multiplier used when setting getting values
};
/// Array of resource_t structs, describing all known resource types.
static const struct resource_t resource_arr[] = {
{RLIMIT_CORE, L"Maximum size of core files created", L'c', 1024},
{RLIMIT_DATA, L"Maximum size of a process’s data segment", L'd', 1024},
{RLIMIT_FSIZE, L"Maximum size of files created by the shell", L'f', 1024},
#ifdef RLIMIT_MEMLOCK
{RLIMIT_MEMLOCK, L"Maximum size that may be locked into memory", L'l', 1024},
#endif
#ifdef RLIMIT_RSS
{RLIMIT_RSS, L"Maximum resident set size", L'm', 1024},
#endif
{RLIMIT_NOFILE, L"Maximum number of open file descriptors", L'n', 1},
{RLIMIT_STACK, L"Maximum stack size", L's', 1024},
{RLIMIT_CPU, L"Maximum amount of cpu time in seconds", L't', 1},
#ifdef RLIMIT_NPROC
{RLIMIT_NPROC, L"Maximum number of processes available to a single user", L'u', 1},
#endif
#ifdef RLIMIT_AS
{RLIMIT_AS, L"Maximum amount of virtual memory available to the shell", L'v', 1024},
#endif
{0, nullptr, 0, 0}};
/// Get the implicit multiplication factor for the specified resource limit.
static int get_multiplier(int what) {
for (int i = 0; resource_arr[i].desc; i++) {
if (resource_arr[i].resource == what) {
return resource_arr[i].multiplier;
}
}
return -1;
}
/// Return the value for the specified resource limit. This function does _not_ multiply the limit
/// value by the multiplier constant used by the commandline ulimit.
static rlim_t get(int resource, int hard) {
struct rlimit ls;
getrlimit(resource, &ls);
return hard ? ls.rlim_max : ls.rlim_cur;
}
/// Print the value of the specified resource limit.
static void print(int resource, int hard, io_streams_t &streams) {
rlim_t l = get(resource, hard);
if (l == RLIM_INFINITY)
streams.out.append(L"unlimited\n");
else
streams.out.append_format(L"%d\n", l / get_multiplier(resource));
}
/// Print values of all resource limits.
static void print_all(int hard, io_streams_t &streams) {
int i;
int w = 0;
for (i = 0; resource_arr[i].desc; i++) {
w = std::max(w, fish_wcswidth(resource_arr[i].desc));
}
for (i = 0; resource_arr[i].desc; i++) {
struct rlimit ls;
rlim_t l;
getrlimit(resource_arr[i].resource, &ls);
l = hard ? ls.rlim_max : ls.rlim_cur;
const wchar_t *unit =
((resource_arr[i].resource == RLIMIT_CPU)
? L"(seconds, "
: (get_multiplier(resource_arr[i].resource) == 1 ? L"(" : L"(kB, "));
streams.out.append_format(L"%-*ls %10ls-%lc) ", w, resource_arr[i].desc, unit,
resource_arr[i].switch_char);
if (l == RLIM_INFINITY) {
streams.out.append(L"unlimited\n");
} else {
streams.out.append_format(L"%d\n", l / get_multiplier(resource_arr[i].resource));
}
}
}
/// Returns the description for the specified resource limit.
static const wchar_t *get_desc(int what) {
int i;
for (i = 0; resource_arr[i].desc; i++) {
if (resource_arr[i].resource == what) {
return resource_arr[i].desc;
}
}
return L"Not a resource";
}
/// Set the new value of the specified resource limit. This function does _not_ multiply the limit
// value by the multiplier constant used by the commandline ulimit.
static int set_limit(int resource, int hard, int soft, rlim_t value, io_streams_t &streams) {
struct rlimit ls;
getrlimit(resource, &ls);
if (hard) ls.rlim_max = value;
if (soft) {
ls.rlim_cur = value;
// Do not attempt to set the soft limit higher than the hard limit.
if ((value == RLIM_INFINITY && ls.rlim_max != RLIM_INFINITY) ||
(value != RLIM_INFINITY && ls.rlim_max != RLIM_INFINITY && value > ls.rlim_max)) {
ls.rlim_cur = ls.rlim_max;
}
}
if (setrlimit(resource, &ls)) {
if (errno == EPERM) {
streams.err.append_format(
L"ulimit: Permission denied when changing resource of type '%ls'\n",
get_desc(resource));
} else {
builtin_wperror(L"ulimit", streams);
}
return STATUS_CMD_ERROR;
}
return STATUS_CMD_OK;
}
/// The ulimit builtin, used for setting resource limits.
maybe_t<int> builtin_ulimit(parser_t &parser, io_streams_t &streams, wchar_t **argv) {
wchar_t *cmd = argv[0];
int argc = builtin_count_args(argv);
bool report_all = false;
bool hard = false;
bool soft = false;
int what = RLIMIT_FSIZE;
static const wchar_t *const short_options = L":HSacdflmnstuvh";
static const struct woption long_options[] = {
{L"all", no_argument, nullptr, 'a'},
{L"hard", no_argument, nullptr, 'H'},
{L"soft", no_argument, nullptr, 'S'},
{L"core-size", no_argument, nullptr, 'c'},
{L"data-size", no_argument, nullptr, 'd'},
{L"file-size", no_argument, nullptr, 'f'},
{L"lock-size", no_argument, nullptr, 'l'},
{L"resident-set-size", no_argument, nullptr, 'm'},
{L"file-descriptor-count", no_argument, nullptr, 'n'},
{L"stack-size", no_argument, nullptr, 's'},
{L"cpu-time", no_argument, nullptr, 't'},
{L"process-count", no_argument, nullptr, 'u'},
{L"virtual-memory-size", no_argument, nullptr, 'v'},
{L"help", no_argument, nullptr, 'h'},
{nullptr, 0, nullptr, 0}};
int opt;
wgetopter_t w;
while ((opt = w.wgetopt_long(argc, argv, short_options, long_options, nullptr)) != -1) {
switch (opt) {
case 'a': {
report_all = true;
break;
}
case 'H': {
hard = true;
break;
}
case 'S': {
soft = true;
break;
}
case 'c': {
what = RLIMIT_CORE;
break;
}
case 'd': {
what = RLIMIT_DATA;
break;
}
case 'f': {
what = RLIMIT_FSIZE;
break;
}
#ifdef RLIMIT_MEMLOCK
case 'l': {
what = RLIMIT_MEMLOCK;
break;
}
#endif
#ifdef RLIMIT_RSS
case 'm': {
what = RLIMIT_RSS;
break;
}
#endif
case 'n': {
what = RLIMIT_NOFILE;
break;
}
case 's': {
what = RLIMIT_STACK;
break;
}
case 't': {
what = RLIMIT_CPU;
break;
}
#ifdef RLIMIT_NPROC
case 'u': {
what = RLIMIT_NPROC;
break;
}
#endif
#ifdef RLIMIT_AS
case 'v': {
what = RLIMIT_AS;
break;
}
#endif
case 'h': {
builtin_print_help(parser, streams, cmd);
return STATUS_CMD_OK;
}
case ':': {
builtin_missing_argument(parser, streams, cmd, argv[w.woptind - 1]);
return STATUS_INVALID_ARGS;
}
case '?': {
builtin_unknown_option(parser, streams, cmd, argv[w.woptind - 1]);
return STATUS_INVALID_ARGS;
}
default: {
DIE("unexpected retval from wgetopt_long");
}
}
}
if (report_all) {
print_all(hard, streams);
return STATUS_CMD_OK;
}
int arg_count = argc - w.woptind;
if (arg_count == 0) {
// Show current limit value.
print(what, hard, streams);
return STATUS_CMD_OK;
} else if (arg_count != 1) {
streams.err.append_format(BUILTIN_ERR_TOO_MANY_ARGUMENTS, cmd);
builtin_print_error_trailer(parser, streams.err, cmd);
return STATUS_INVALID_ARGS;
}
// Change current limit value.
if (!hard && !soft) {
// Set both hard and soft limits if neither was specified.
hard = soft = true;
}
rlim_t new_limit;
if (*argv[w.woptind] == L'\0') {
streams.err.append_format(_(L"%ls: New limit cannot be an empty string\n"), cmd);
builtin_print_error_trailer(parser, streams.err, cmd);
return STATUS_INVALID_ARGS;
} else if (wcscasecmp(argv[w.woptind], L"unlimited") == 0) {
new_limit = RLIM_INFINITY;
} else if (wcscasecmp(argv[w.woptind], L"hard") == 0) {
new_limit = get(what, 1);
} else if (wcscasecmp(argv[w.woptind], L"soft") == 0) {
new_limit = get(what, soft);
} else {
new_limit = fish_wcstol(argv[w.woptind]);
if (errno) {
streams.err.append_format(_(L"%ls: Invalid limit '%ls'\n"), cmd, argv[w.woptind]);
builtin_print_error_trailer(parser, streams.err, cmd);
return STATUS_INVALID_ARGS;
}
new_limit *= get_multiplier(what);
}
return set_limit(what, hard, soft, new_limit, streams);
}