24165447443

Committed 08 Apr 2026 10:44PM UTC coverage: 72.303% (+0.1%) from 72.175%

Build # 24165447443

Build Type

push

github

Committed by

bluca

Commit Message

compress: write sparse files when decompressing to regular files

Core dumps are often very sparse, containing large zero-filled regions
whose actual disk usage can be significantly reduced by preserving
holes. Previously, decompress_stream() always wrote dense output,
expanding all zero regions into allocated disk blocks.

Each decompression backend (xz, lz4, zstd) now auto-detects whether the
output fd is suitable for sparse writes via a shared should_sparse()
helper. The check requires both S_ISREG (regular file) and !O_APPEND,
since O_APPEND causes write() to ignore the file position set by
lseek(), which would collapse the holes and corrupt the output. For
pipes, sockets, and append-mode files, dense writes are preserved via
loop_write_full() with USEC_INFINITY timeout, matching the original
behavior. After sparse decompression, finalize_sparse() sets the final
file size to account for any trailing holes.

This is transparent to callers — all public signatures are unchanged.
coredumpctl benefits automatically:
- coredumpctl debug: temp file in /var/tmp is now sparse
- coredumpctl dump -o file: output file is now sparse
- coredumpctl dump > file: redirected stdout is now sparse
- coredumpctl dump | ...: pipe output unchanged (dense)
- coredumpctl dump >> file: append mode, falls back to dense

Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>
Co-developed-by: Codex (GPT-5) <noreply@openai.com>

Coverage Stats

123 of 132 new or added lines in 2 files covered. (93.18%)

5704 existing lines in 82 files now uncovered.

319660 of 442111 relevant lines covered (72.3%)

1196031.58 hits per line

Source File
Press 'n' to go to next uncovered line, 'b' for previous

93.71

/src/basic/uid-range.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sched.h>
#include <string.h>

#include "alloc-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "format-util.h"
#include "namespace-util.h"
#include "path-util.h"
#include "pidref.h"
#include "process-util.h"
#include "sort-util.h"
#include "stat-util.h"
#include "uid-range.h"
#include "user-util.h"

UIDRange *uid_range_free(UIDRange *range) {
        if (!range)
                return NULL;

        free(range->entries);
        return mfree(range);
}

static bool uid_range_entry_intersect(const UIDRangeEntry *a, const UIDRangeEntry *b) {
        assert(a);
        assert(b);

        return a->start <= b->start + b->nr && a->start + a->nr >= b->start;
}

static int uid_range_entry_compare(const UIDRangeEntry *a, const UIDRangeEntry *b) {
        int r;

        assert(a);
        assert(b);

        r = CMP(a->start, b->start);
        if (r != 0)
                return r;

        return CMP(a->nr, b->nr);
}

static void uid_range_coalesce(UIDRange *range) {
        assert(range);

        if (range->n_entries <= 0)
                return;

        typesafe_qsort(range->entries, range->n_entries, uid_range_entry_compare);

        for (size_t i = 0; i < range->n_entries; i++) {
                UIDRangeEntry *x = range->entries + i;

                for (size_t j = i + 1; j < range->n_entries; j++) {
                        UIDRangeEntry *y = range->entries + j;
                        uid_t begin, end;

                        if (!uid_range_entry_intersect(x, y))
                                break;

                        begin = MIN(x->start, y->start);

                        /* Silence static analyzers, overflow is prevented by uid_range_add_internal() */
                        assert(x->start <= UINT32_MAX - x->nr);
                        assert(y->start <= UINT32_MAX - y->nr);
                        end = MAX(x->start + x->nr, y->start + y->nr);

                        x->start = begin;
                        x->nr = end - begin;

                        if (range->n_entries > j + 1)
                                memmove(y, y + 1, sizeof(UIDRangeEntry) * (range->n_entries - j - 1));

                        range->n_entries--;

                        /* Silence static analyzers, j cannot be 0 here since it starts at i + 1, i.e. >= 1 */
                        assert(j > 0);
                        j--;
                }
        }
}

int uid_range_add_internal(UIDRange **range, uid_t start, uid_t nr, bool coalesce) {
        _cleanup_(uid_range_freep) UIDRange *range_new = NULL;
        UIDRange *p;

        assert(range);

        if (nr <= 0)
                return 0;

        if (start > UINT32_MAX - nr) /* overflow check */
                return -ERANGE;

        if (*range)
                p = *range;
        else {
                range_new = new0(UIDRange, 1);
                if (!range_new)
                        return -ENOMEM;

                p = range_new;
        }

        if (!GREEDY_REALLOC(p->entries, p->n_entries + 1))
                return -ENOMEM;

        p->entries[p->n_entries++] = (UIDRangeEntry) {
                .start = start,
                .nr = nr,
        };

        if (coalesce)
                uid_range_coalesce(p);

        TAKE_PTR(range_new);
        *range = p;

        return 0;
}

int uid_range_add_str_full(UIDRange **range, const char *s, bool coalesce) {
        uid_t start, end;
        int r;

        assert(range);
        assert(s);

        r = parse_uid_range(s, &start, &end);
        if (r < 0)
                return r;

        return uid_range_add_internal(range, start, end - start + 1, coalesce);
}

int uid_range_next_lower(const UIDRange *range, uid_t *uid) {
        uid_t closest = UID_INVALID, candidate;

        assert(range);
        assert(uid);

        if (*uid == 0)
                return -EBUSY;

        candidate = *uid - 1;

        for (size_t i = 0; i < range->n_entries; i++) {
                uid_t begin, end;

                begin = range->entries[i].start;
                end = range->entries[i].start + range->entries[i].nr - 1;

                if (candidate >= begin && candidate <= end) {
                        *uid = candidate;
                        return 1;
                }

                if (end < candidate)
                        closest = end;
        }

        if (closest == UID_INVALID)
                return -EBUSY;

        *uid = closest;
        return 1;
}

bool uid_range_covers(const UIDRange *range, uid_t start, uid_t nr) {
        if (nr == 0) /* empty range? always covered... */
                return true;

        if (start > UINT32_MAX - nr) /* range overflows? definitely not covered... */
                return false;

        if (!range)
                return false;

        FOREACH_ARRAY(i, range->entries, range->n_entries)
                if (start >= i->start &&
                    start + nr <= i->start + i->nr)
                        return true;

        return false;
}

int uid_map_read_one(FILE *f, uid_t *ret_base, uid_t *ret_shift, uid_t *ret_range) {
        uid_t uid_base, uid_shift, uid_range;
        int r;

        assert(f);

        errno = 0;
        r = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT "\n", &uid_base, &uid_shift, &uid_range);
        if (r == EOF)
                return errno_or_else(ENOMSG);
        assert(r >= 0);
        if (r != 3)
                return -EBADMSG;
        if (uid_range <= 0)
                return -EBADMSG;

        if (ret_base)
                *ret_base = uid_base;
        if (ret_shift)
                *ret_shift = uid_shift;
        if (ret_range)
                *ret_range = uid_range;

        return 0;
}

unsigned uid_range_size(const UIDRange *range) {
        if (!range)
                return 0;

        unsigned n = 0;

        FOREACH_ARRAY(e, range->entries, range->n_entries)
                n += e->nr;

        return n;
}

bool uid_range_is_empty(const UIDRange *range) {

        if (!range)
                return true;

        FOREACH_ARRAY(e, range->entries, range->n_entries)
                if (e->nr > 0)
                        return false;

        return true;
}

int uid_range_load_userns_full(const char *path, UIDRangeUsernsMode mode, bool coalesce, UIDRange **ret) {
        _cleanup_(uid_range_freep) UIDRange *range = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        /* If 'path' is NULL loads the UID range of the userns namespace we run. Otherwise load the data from
         * the specified file (which can be either uid_map or gid_map, in case caller needs to deal with GID
         * maps).
         *
         * To simplify things this will modify the passed array in case of later failure. */

        assert(mode >= 0);
        assert(mode < _UID_RANGE_USERNS_MODE_MAX);
        assert(ret);

        if (!path)
                path = IN_SET(mode, UID_RANGE_USERNS_INSIDE, UID_RANGE_USERNS_OUTSIDE) ? "/proc/self/uid_map" : "/proc/self/gid_map";

        f = fopen(path, "re");
        if (!f) {
                r = -errno;

                if (r == -ENOENT && path_startswith(path, "/proc/"))
                        return proc_mounted() > 0 ? -EOPNOTSUPP : -ENOSYS;

                return r;
        }

        range = new0(UIDRange, 1);
        if (!range)
                return -ENOMEM;

        for (;;) {
                uid_t uid_base, uid_shift, uid_range;

                r = uid_map_read_one(f, &uid_base, &uid_shift, &uid_range);
                if (r == -ENOMSG)
                        break;
                if (r < 0)
                        return r;

                r = uid_range_add_internal(
                                &range,
                                IN_SET(mode, UID_RANGE_USERNS_INSIDE, GID_RANGE_USERNS_INSIDE) ? uid_base : uid_shift,
                                uid_range,
                                /* coalesce= */ false);
                if (r < 0)
                        return r;
        }

        if (coalesce)
                uid_range_coalesce(range);

        *ret = TAKE_PTR(range);
        return 0;
}

int uid_range_load_userns_by_fd_full(int userns_fd, UIDRangeUsernsMode mode, bool coalesce, UIDRange **ret) {
        _cleanup_(pidref_done_sigkill_wait) PidRef pidref = PIDREF_NULL;
        int r;

        assert(userns_fd >= 0);
        assert(mode >= 0);
        assert(mode < _UID_RANGE_USERNS_MODE_MAX);
        assert(ret);

        r = is_our_namespace(userns_fd, NAMESPACE_USER);
        if (r < 0)
                return r;
        if (r > 0)
                return uid_range_load_userns_full(/* path= */ NULL, mode, coalesce, ret);

        r = userns_enter_and_pin(userns_fd, &pidref);
        if (r < 0)
                return r;

        const char *p = procfs_file_alloca(
                        pidref.pid,
                        IN_SET(mode, UID_RANGE_USERNS_INSIDE, UID_RANGE_USERNS_OUTSIDE) ? "uid_map" : "gid_map");

        return uid_range_load_userns_full(p, mode, coalesce, ret);
}

bool uid_range_overlaps(const UIDRange *range, uid_t start, uid_t nr) {

        if (!range)
                return false;

        /* Avoid overflow */
        if (start > UINT32_MAX - nr)
                nr = UINT32_MAX - start;

        if (nr == 0)
                return false;

        FOREACH_ARRAY(entry, range->entries, range->n_entries)
                if (start < entry->start + entry->nr &&
                    start + nr >= entry->start)
                        return true;

        return false;
}

int uid_range_clip(UIDRange *range, uid_t min, uid_t max) {
        assert(range);

        if (min > max)
                return -EINVAL;

        size_t t = 0;
        FOREACH_ARRAY(e, range->entries, range->n_entries) {
                uid_t entry_end = e->start + e->nr; /* one past the last UID in entry */

                /* Skip entries completely outside [min, max] */
                if (entry_end <= min || e->start > max)
                        continue;

                /* Trim the entry to fit within [min, max] */
                uid_t new_start = MAX(e->start, min);
                /* entry_end is exclusive, avoid overflow when max == UINT32_MAX */
                uid_t new_end = entry_end <= max ? entry_end : max + 1;
                assert(new_end > new_start);

                range->entries[t++] = (UIDRangeEntry) {
                        .start = new_start,
                        .nr = new_end - new_start,
                };
        }

        range->n_entries = t;

        return 0;
}

int uid_range_partition(UIDRange *range, uid_t size) {
        assert(range);
        assert(size > 0);

        /* Partitions the UID range entries into buckets of the given size. Any entry larger than the given
         * size will be partitioned into multiple entries, each of the given size. Any leftover UIDs in the
         * entry are dropped. Any entries smaller than the given size are also dropped. */

        /* Count how many entries we'll need after partitioning */
        size_t n_new_entries = 0;
        FOREACH_ARRAY(e, range->entries, range->n_entries)
                n_new_entries += e->nr / size;

        if (n_new_entries == 0) {
                range->n_entries = 0;
                return 0;
        }

        if (n_new_entries > range->n_entries && !GREEDY_REALLOC(range->entries, n_new_entries))
                return -ENOMEM;

        /* Work backwards to avoid overwriting entries we still need to read */
        size_t t = n_new_entries;
        for (size_t i = range->n_entries; i > 0; i--) {
                UIDRangeEntry *e = range->entries + i - 1;
                unsigned n_parts = e->nr / size;

                for (unsigned j = n_parts; j > 0; j--)
                        range->entries[--t] = (UIDRangeEntry) {
                                .start = e->start + (j - 1) * size,
                                .nr = size,
                        };
        }

        range->n_entries = n_new_entries;

        return 0;
}

int uid_range_copy(const UIDRange *range, UIDRange **ret) {
        assert(ret);

        if (!range) {
                *ret = NULL;
                return 0;
        }

        _cleanup_(uid_range_freep) UIDRange *copy = new0(UIDRange, 1);
        if (!copy)
                return -ENOMEM;

        if (range->n_entries > 0) {
                copy->entries = newdup(UIDRangeEntry, range->entries, range->n_entries);
                if (!copy->entries)
                        return -ENOMEM;

                copy->n_entries = range->n_entries;
        }

        *ret = TAKE_PTR(copy);
        return 0;
}

int uid_range_remove(UIDRange *range, uid_t start, uid_t size) {
        assert(range);

        if (size == 0)
                return 0;

        uid_t end = start + size; /* one past the last UID to remove */

        for (size_t i = 0; i < range->n_entries; i++) {
                UIDRangeEntry *e = range->entries + i;
                uid_t entry_end = e->start + e->nr;

                /* No overlap */
                if (entry_end <= start || e->start >= end)
                        continue;

                /* Check if this removal splits the entry into two parts */
                if (e->start < start && entry_end > end) {
                        /* Need to split: grow the array first */
                        if (!GREEDY_REALLOC(range->entries, range->n_entries + 1))
                                return -ENOMEM;

                        /* Re-fetch pointer after potential realloc */
                        e = range->entries + i;
                        entry_end = e->start + e->nr;

                        /* Shift everything after this entry to make room */
                        memmove(range->entries + i + 2, range->entries + i + 1,
                                (range->n_entries - i - 1) * sizeof(UIDRangeEntry));
                        range->n_entries++;

                        /* First part: before the removed range */
                        range->entries[i] = (UIDRangeEntry) {
                                .start = e->start,
                                .nr = start - e->start,
                        };

                        /* Second part: after the removed range */
                        range->entries[i + 1] = (UIDRangeEntry) {
                                .start = end,
                                .nr = entry_end - end,
                        };

                        /* Skip the newly inserted entry */
                        i++;
                        continue;
                }

                /* Removal covers the entire entry */
                if (start <= e->start && end >= entry_end) {
                        memmove(e, e + 1, (range->n_entries - i - 1) * sizeof(UIDRangeEntry));
                        range->n_entries--;
                        i--;
                        continue;
                }

                /* Removal trims the start of the entry */
                if (start <= e->start && end > e->start) {
                        e->nr = entry_end - end;
                        e->start = end;
                        continue;
                }

                /* Removal trims the end of the entry */
                if (start < entry_end && end >= entry_end) {
                        e->nr = start - e->start;
                        continue;
                }
        }

        return 0;
}

int uid_range_translate(const UIDRange *outside, const UIDRange *inside, uid_t uid, uid_t *ret) {
        assert(uid_range_entries(outside) == uid_range_entries(inside));
        assert(ret);

        /* Given two UID ranges that represent the outside UID range of a user namespace (the 2nd and 3rd
         * columns in /proc/xxx/uid_map) and the inside UID range of a user namespace (the 1st and 3rd
         * columns in /proc/xxx/uid_map), translates the given UID from the outside range to the inside
         * range. For example, given the following UID range:
         *
         * 0 1000 1
         *
         * calling uid_range_translate(outside, inside, 1000) will return 0 as the output UID. Alternatively,
         * calling uid_range_translate(inside, outside, 0) will return 1000 as the output UID.
         */

        for (size_t i = 0; i < uid_range_entries(outside); i++)
                assert(outside->entries[i].nr == inside->entries[i].nr);

        for (size_t i = 0; i < uid_range_entries(outside); i++) {
                const UIDRangeEntry *e = outside->entries + i;

                if (uid < e->start || uid >= e->start + e->nr)
                        continue;

                *ret = inside->entries[i].start + uid - e->start;
                return 0;
        }

        return -ESRCH;
}

int uid_range_translate_userns_fd(int userns_fd, UIDRangeUsernsMode mode, uid_t uid, uid_t *ret) {
        int r;

        assert(userns_fd >= 0);
        assert(IN_SET(mode, UID_RANGE_USERNS_OUTSIDE, GID_RANGE_USERNS_OUTSIDE));

        _cleanup_(uid_range_freep) UIDRange *outside_range = NULL;
        r = uid_range_load_userns_by_fd_full(userns_fd, mode, /* coalesce= */ false, &outside_range);
        if (r < 0)
                return r;

        mode = mode == UID_RANGE_USERNS_OUTSIDE ? UID_RANGE_USERNS_INSIDE : GID_RANGE_USERNS_INSIDE;

        _cleanup_(uid_range_freep) UIDRange *inside_range = NULL;
        r = uid_range_load_userns_by_fd_full(userns_fd, mode, /* coalesce= */ false, &inside_range);
        if (r < 0)
                return r;

        return uid_range_translate(outside_range, inside_range, uid, ret);
}

bool uid_range_equal(const UIDRange *a, const UIDRange *b) {
        if (a == b)
                return true;

        if (!a || !b)
                return false;

        if (a->n_entries != b->n_entries)
                return false;

        for (size_t i = 0; i < a->n_entries; i++) {
                if (a->entries[i].start != b->entries[i].start)
                        return false;
                if (a->entries[i].nr != b->entries[i].nr)
                        return false;
        }

        return true;
}

int uid_map_search_root(pid_t pid, UIDRangeUsernsMode mode, uid_t *ret) {
        int r;

        assert(pid_is_valid(pid));
        assert(IN_SET(mode, UID_RANGE_USERNS_OUTSIDE, GID_RANGE_USERNS_OUTSIDE));

        const char *p = procfs_file_alloca(pid, mode == UID_RANGE_USERNS_OUTSIDE ? "uid_map" : "gid_map");
        _cleanup_fclose_ FILE *f = fopen(p, "re");
        if (!f) {
                if (errno != ENOENT)
                        return -errno;

                r = proc_mounted();
                if (r < 0)
                        return -ENOENT; /* original error, if we can't determine /proc/ state */

                return r ? -ENOPKG : -ENOSYS;
        }

        for (;;) {
                uid_t uid_base = UID_INVALID, uid_shift = UID_INVALID;

                r = uid_map_read_one(f, &uid_base, &uid_shift, /* ret_range= */ NULL);
                if (r < 0)
                        return r;

                if (uid_base == 0) {
                        if (ret)
                                *ret = uid_shift;
                        return 0;
                }
        }
}

uid_t uid_range_base(const UIDRange *range) {

        /* Returns the lowest UID in the range (notw that elements are sorted, hence we just need to look at
         * the first one that is populated. */

        if (uid_range_is_empty(range))
                return UID_INVALID;

        FOREACH_ARRAY(e, range->entries, range->n_entries)
                if (e->nr > 0)
                        return e->start;

        return UID_INVALID;
}

1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
2
3	#include <sched.h>
4	#include <string.h>
5
6	#include "alloc-util.h"
7	#include "errno-util.h"
8	#include "fd-util.h"
9	#include "format-util.h"
10	#include "namespace-util.h"
11	#include "path-util.h"
12	#include "pidref.h"
13	#include "process-util.h"
14	#include "sort-util.h"
15	#include "stat-util.h"
16	#include "uid-range.h"
17	#include "user-util.h"
18
19	UIDRange uid_range_free(UIDRange range) {	4,256✔
20	if (!range)	4,256✔
21	return NULL;
22
23	free(range->entries);	1,161✔
24	return mfree(range);	1,161✔
25	}
26
27	static bool uid_range_entry_intersect(const UIDRangeEntry a, const UIDRangeEntry b) {	108✔
28	assert(a);	108✔
29	assert(b);	108✔
30
31	return a->start <= b->start + b->nr && a->start + a->nr >= b->start;	108✔
32	}
33
34	static int uid_range_entry_compare(const UIDRangeEntry a, const UIDRangeEntry b) {	298✔
35	int r;	298✔
36
37	assert(a);	298✔
38	assert(b);	298✔
39
40	r = CMP(a->start, b->start);	298✔
41	if (r != 0)	139✔
42	return r;	278✔
43
44	return CMP(a->nr, b->nr);	20✔
45	}
46
47	static void uid_range_coalesce(UIDRange *range) {	736✔
48	assert(range);	736✔
49
50	if (range->n_entries <= 0)	736✔
51	return;
52
53	typesafe_qsort(range->entries, range->n_entries, uid_range_entry_compare);	398✔
54
55	for (size_t i = 0; i < range->n_entries; i++) {	816✔
56	UIDRangeEntry *x = range->entries + i;	418✔
57
58	for (size_t j = i + 1; j < range->n_entries; j++) {	506✔
59	UIDRangeEntry *y = range->entries + j;	108✔
60	uid_t begin, end;	108✔
61
62	if (!uid_range_entry_intersect(x, y))	108✔
63	break;
64
65	begin = MIN(x->start, y->start);	88✔
66
67	/* Silence static analyzers, overflow is prevented by uid_range_add_internal() */
68	assert(x->start <= UINT32_MAX - x->nr);	88✔
69	assert(y->start <= UINT32_MAX - y->nr);	88✔
70	end = MAX(x->start + x->nr, y->start + y->nr);	88✔
71
72	x->start = begin;	88✔
73	x->nr = end - begin;	88✔
74
75	if (range->n_entries > j + 1)	88✔
76	memmove(y, y + 1, sizeof(UIDRangeEntry) * (range->n_entries - j - 1));	81✔
77
78	range->n_entries--;	88✔
79
80	/* Silence static analyzers, j cannot be 0 here since it starts at i + 1, i.e. >= 1 */
81	assert(j > 0);	88✔
82	j--;
83	}
84	}
85	}
86
87	int uid_range_add_internal(UIDRange **range, uid_t start, uid_t nr, bool coalesce) {	844✔
88	_cleanup_(uid_range_freep) UIDRange *range_new = NULL;	844✔
89	UIDRange *p;	844✔
90
91	assert(range);	844✔
92
93	if (nr <= 0)	844✔
94	return 0;
95
96	if (start > UINT32_MAX - nr) /* overflow check */	844✔
97	return -ERANGE;
98
99	if (*range)	844✔
100	p = *range;
101	else {
102	range_new = new0(UIDRange, 1);	140✔
103	if (!range_new)	140✔
104	return -ENOMEM;
105
106	p = range_new;
107	}
108
109	if (!GREEDY_REALLOC(p->entries, p->n_entries + 1))	844✔
110	return -ENOMEM;
111
112	p->entries[p->n_entries++] = (UIDRangeEntry) {	844✔
113	.start = start,
114	.nr = nr,
115	};
116
117	if (coalesce)	844✔
118	uid_range_coalesce(p);	152✔
119
120	TAKE_PTR(range_new);	844✔
121	*range = p;	844✔
122
123	return 0;	844✔
124	}
125
126	int uid_range_add_str_full(UIDRange *range, const char s, bool coalesce) {	40✔
127	uid_t start, end;	40✔
128	int r;	40✔
129
130	assert(range);	40✔
131	assert(s);	40✔
132
133	r = parse_uid_range(s, &start, &end);	40✔
134	if (r < 0)	40✔
135	return r;	40✔
136
137	return uid_range_add_internal(range, start, end - start + 1, coalesce);	40✔
138	}
139
140	int uid_range_next_lower(const UIDRange range, uid_t uid) {	272✔
141	uid_t closest = UID_INVALID, candidate;	272✔
142
143	assert(range);	272✔
144	assert(uid);	272✔
145
146	if (*uid == 0)	272✔
147	return -EBUSY;
148
149	candidate = *uid - 1;	272✔
150
151	for (size_t i = 0; i < range->n_entries; i++) {	320✔
152	uid_t begin, end;	272✔
153
154	begin = range->entries[i].start;	272✔
155	end = range->entries[i].start + range->entries[i].nr - 1;	272✔
156
157	if (candidate >= begin && candidate <= end) {	272✔
158	*uid = candidate;	224✔
159	return 1;	224✔
160	}
161
162	if (end < candidate)	48✔
163	closest = end;	47✔
164	}
165
166	if (closest == UID_INVALID)	48✔
167	return -EBUSY;
168
169	*uid = closest;	47✔
170	return 1;	47✔
171	}
172
173	bool uid_range_covers(const UIDRange *range, uid_t start, uid_t nr) {	237✔
174	if (nr == 0) /* empty range? always covered... */	237✔
175	return true;
176
177	if (start > UINT32_MAX - nr) /* range overflows? definitely not covered... */	236✔
178	return false;
179
180	if (!range)	233✔
181	return false;
182
183	FOREACH_ARRAY(i, range->entries, range->n_entries)	249✔
184	if (start >= i->start &&	237✔
185	start + nr <= i->start + i->nr)	231✔
186	return true;
187
188	return false;
189	}
190
191	int uid_map_read_one(FILE f, uid_t ret_base, uid_t ret_shift, uid_t ret_range) {	1,785✔
192	uid_t uid_base, uid_shift, uid_range;	1,785✔
193	int r;	1,785✔
194
195	assert(f);	1,785✔
196
197	errno = 0;	1,785✔
198	r = fscanf(f, UID_FMT " " UID_FMT " " UID_FMT "\n", &uid_base, &uid_shift, &uid_range);	1,785✔
199	if (r == EOF)	1,785✔
200	return errno_or_else(ENOMSG);	999✔
201	assert(r >= 0);	786✔
202	if (r != 3)	786✔
203	return -EBADMSG;
204	if (uid_range <= 0)	786✔
205	return -EBADMSG;
206
207	if (ret_base)	786✔
208	*ret_base = uid_base;	786✔
209	if (ret_shift)	786✔
210	*ret_shift = uid_shift;	786✔
211	if (ret_range)	786✔
212	*ret_range = uid_range;	724✔
213
214	return 0;
215	}
216
217	unsigned uid_range_size(const UIDRange *range) {	7✔
218	if (!range)	7✔
219	return 0;
220
221	unsigned n = 0;	6✔
222
223	FOREACH_ARRAY(e, range->entries, range->n_entries)	16✔
224	n += e->nr;	10✔
225
226	return n;
227	}
228
229	bool uid_range_is_empty(const UIDRange *range) {	536✔
230
231	if (!range)	536✔
232	return true;
233
234	FOREACH_ARRAY(e, range->entries, range->n_entries)	534✔
235	if (e->nr > 0)	191✔
236	return false;
237
238	return true;
239	}
240
241	int uid_range_load_userns_full(const char path, UIDRangeUsernsMode mode, bool coalesce, UIDRange *ret) {	928✔
UNCOV 242	_cleanup_(uid_range_freep) UIDRange *range = NULL;	×
243	_cleanup_fclose_ FILE *f = NULL;	928✔
244	int r;	928✔
245
246	/* If 'path' is NULL loads the UID range of the userns namespace we run. Otherwise load the data from
247	* the specified file (which can be either uid_map or gid_map, in case caller needs to deal with GID
248	* maps).
249	*
250	* To simplify things this will modify the passed array in case of later failure. */
251
252	assert(mode >= 0);	928✔
253	assert(mode < _UID_RANGE_USERNS_MODE_MAX);	928✔
254	assert(ret);	928✔
255
256	if (!path)	928✔
257	path = IN_SET(mode, UID_RANGE_USERNS_INSIDE, UID_RANGE_USERNS_OUTSIDE) ? "/proc/self/uid_map" : "/proc/self/gid_map";	576✔
258
259	f = fopen(path, "re");	928✔
260	if (!f) {	928✔
261	r = -errno;	×
262
UNCOV 263	if (r == -ENOENT && path_startswith(path, "/proc/"))	×
UNCOV 264	return proc_mounted() > 0 ? -EOPNOTSUPP : -ENOSYS;	×
265
266	return r;
267	}
268
269	range = new0(UIDRange, 1);	928✔
270	if (!range)	928✔
271	return -ENOMEM;
272
273	for (;;) {	606✔
274	uid_t uid_base, uid_shift, uid_range;	1,534✔
275
276	r = uid_map_read_one(f, &uid_base, &uid_shift, &uid_range);	1,534✔
277	if (r == -ENOMSG)	1,534✔
278	break;
279	if (r < 0)	606✔
UNCOV 280	return r;	×
281
282	r = uid_range_add_internal(	606✔
283	&range,
284	IN_SET(mode, UID_RANGE_USERNS_INSIDE, GID_RANGE_USERNS_INSIDE) ? uid_base : uid_shift,	606✔
285	uid_range,
286	/* coalesce= */ false);
287	if (r < 0)	606✔
288	return r;
289	}
290
291	if (coalesce)	928✔
292	uid_range_coalesce(range);	584✔
293
294	*ret = TAKE_PTR(range);	928✔
295	return 0;	928✔
296	}
297
298	int uid_range_load_userns_by_fd_full(int userns_fd, UIDRangeUsernsMode mode, bool coalesce, UIDRange **ret) {	775✔
299	_cleanup_(pidref_done_sigkill_wait) PidRef pidref = PIDREF_NULL;	775✔
300	int r;	775✔
301
302	assert(userns_fd >= 0);	775✔
303	assert(mode >= 0);	775✔
304	assert(mode < _UID_RANGE_USERNS_MODE_MAX);	775✔
305	assert(ret);	775✔
306
307	r = is_our_namespace(userns_fd, NAMESPACE_USER);	775✔
308	if (r < 0)	775✔
309	return r;
310	if (r > 0)	775✔
311	return uid_range_load_userns_full(/* path= */ NULL, mode, coalesce, ret);	424✔
312
313	r = userns_enter_and_pin(userns_fd, &pidref);	351✔
314	if (r < 0)	351✔
315	return r;
316
317	const char *p = procfs_file_alloca(	351✔
318	pidref.pid,
319	IN_SET(mode, UID_RANGE_USERNS_INSIDE, UID_RANGE_USERNS_OUTSIDE) ? "uid_map" : "gid_map");
320
321	return uid_range_load_userns_full(p, mode, coalesce, ret);	351✔
322	}
323
UNCOV 324	bool uid_range_overlaps(const UIDRange *range, uid_t start, uid_t nr) {	×
325
UNCOV 326	if (!range)	×
327	return false;
328
329	/* Avoid overflow */
330	if (start > UINT32_MAX - nr)	×
UNCOV 331	nr = UINT32_MAX - start;	×
332
333	if (nr == 0)	×
334	return false;
335
UNCOV 336	FOREACH_ARRAY(entry, range->entries, range->n_entries)	×
UNCOV 337	if (start < entry->start + entry->nr &&	×
UNCOV 338	start + nr >= entry->start)	×
339	return true;
340
341	return false;
342	}
343
344	int uid_range_clip(UIDRange *range, uid_t min, uid_t max) {	97✔
345	assert(range);	97✔
346
347	if (min > max)	97✔
348	return -EINVAL;
349
350	size_t t = 0;	96✔
351	FOREACH_ARRAY(e, range->entries, range->n_entries) {	209✔
352	uid_t entry_end = e->start + e->nr; /* one past the last UID in entry */	113✔
353
354	/* Skip entries completely outside [min, max] */
355	if (entry_end <= min \|\| e->start > max)	113✔
356	continue;	6✔
357
358	/* Trim the entry to fit within [min, max] */
359	uid_t new_start = MAX(e->start, min);	107✔
360	/* entry_end is exclusive, avoid overflow when max == UINT32_MAX */
361	uid_t new_end = entry_end <= max ? entry_end : max + 1;	107✔
362	assert(new_end > new_start);	107✔
363
364	range->entries[t++] = (UIDRangeEntry) {	107✔
365	.start = new_start,
366	.nr = new_end - new_start,	107✔
367	};
368	}
369
370	range->n_entries = t;	96✔
371
372	return 0;	96✔
373	}
374
375	int uid_range_partition(UIDRange *range, uid_t size) {	95✔
376	assert(range);	95✔
377	assert(size > 0);	95✔
378
379	/* Partitions the UID range entries into buckets of the given size. Any entry larger than the given
380	* size will be partitioned into multiple entries, each of the given size. Any leftover UIDs in the
381	* entry are dropped. Any entries smaller than the given size are also dropped. */
382
383	/* Count how many entries we'll need after partitioning */
384	size_t n_new_entries = 0;	95✔
385	FOREACH_ARRAY(e, range->entries, range->n_entries)	200✔
386	n_new_entries += e->nr / size;	105✔
387
388	if (n_new_entries == 0) {	95✔
389	range->n_entries = 0;	1✔
390	return 0;	1✔
391	}
392
393	if (n_new_entries > range->n_entries && !GREEDY_REALLOC(range->entries, n_new_entries))	94✔
394	return -ENOMEM;
395
396	/* Work backwards to avoid overwriting entries we still need to read */
397	size_t t = n_new_entries;	94✔
398	for (size_t i = range->n_entries; i > 0; i--) {	198✔
399	UIDRangeEntry *e = range->entries + i - 1;	104✔
400	unsigned n_parts = e->nr / size;	104✔
401
402	for (unsigned j = n_parts; j > 0; j--)	2,493,798✔
403	range->entries[--t] = (UIDRangeEntry) {	2,493,694✔
404	.start = e->start + (j - 1) * size,	2,493,694✔
405	.nr = size,
406	};
407	}
408
409	range->n_entries = n_new_entries;	94✔
410
411	return 0;	94✔
412	}
413
414	int uid_range_copy(const UIDRange range, UIDRange *ret) {	93✔
415	assert(ret);	93✔
416
417	if (!range) {	93✔
418	*ret = NULL;	1✔
419	return 0;	93✔
420	}
421
422	_cleanup_(uid_range_freep) UIDRange *copy = new0(UIDRange, 1);	92✔
423	if (!copy)	92✔
424	return -ENOMEM;
425
426	if (range->n_entries > 0) {	92✔
427	copy->entries = newdup(UIDRangeEntry, range->entries, range->n_entries);	91✔
428	if (!copy->entries)	91✔
429	return -ENOMEM;
430
431	copy->n_entries = range->n_entries;	91✔
432	}
433
434	*ret = TAKE_PTR(copy);	92✔
435	return 0;	92✔
436	}
437
438	int uid_range_remove(UIDRange *range, uid_t start, uid_t size) {	99✔
439	assert(range);	99✔
440
441	if (size == 0)	99✔
442	return 0;
443
444	uid_t end = start + size; /* one past the last UID to remove */	98✔
445
446	for (size_t i = 0; i < range->n_entries; i++) {	210✔
447	UIDRangeEntry *e = range->entries + i;	112✔
448	uid_t entry_end = e->start + e->nr;	112✔
449
450	/* No overlap */
451	if (entry_end <= start \|\| e->start >= end)	112✔
452	continue;	14✔
453
454	/* Check if this removal splits the entry into two parts */
455	if (e->start < start && entry_end > end) {	98✔
456	/* Need to split: grow the array first */
457	if (!GREEDY_REALLOC(range->entries, range->n_entries + 1))	88✔
458	return -ENOMEM;
459
460	/* Re-fetch pointer after potential realloc */
461	e = range->entries + i;	88✔
462	entry_end = e->start + e->nr;	88✔
463
464	/* Shift everything after this entry to make room */
465	memmove(range->entries + i + 2, range->entries + i + 1,	88✔
466	(range->n_entries - i - 1) * sizeof(UIDRangeEntry));	88✔
467	range->n_entries++;	88✔
468
469	/* First part: before the removed range */
470	range->entries[i] = (UIDRangeEntry) {	88✔
471	.start = e->start,	88✔
472	.nr = start - e->start,	88✔
473	};
474
475	/* Second part: after the removed range */
476	range->entries[i + 1] = (UIDRangeEntry) {	88✔
477	.start = end,
478	.nr = entry_end - end,	88✔
479	};
480
481	/* Skip the newly inserted entry */
482	i++;	88✔
483	continue;	88✔
484	}
485
486	/* Removal covers the entire entry */
487	if (start <= e->start && end >= entry_end) {	10✔
488	memmove(e, e + 1, (range->n_entries - i - 1) * sizeof(UIDRangeEntry));	6✔
489	range->n_entries--;	6✔
490	i--;	6✔
491	continue;	6✔
492	}
493
494	/* Removal trims the start of the entry */
495	if (start <= e->start && end > e->start) {	4✔
496	e->nr = entry_end - end;	2✔
497	e->start = end;	2✔
498	continue;	2✔
499	}
500
501	/* Removal trims the end of the entry */
502	if (start < entry_end && end >= entry_end) {	2✔
503	e->nr = start - e->start;	2✔
504	continue;	2✔
505	}
506	}
507
508	return 0;
509	}
510
511	int uid_range_translate(const UIDRange outside, const UIDRange inside, uid_t uid, uid_t *ret) {	214✔
512	assert(uid_range_entries(outside) == uid_range_entries(inside));	642✔
513	assert(ret);	214✔
514
515	/* Given two UID ranges that represent the outside UID range of a user namespace (the 2nd and 3rd
516	* columns in /proc/xxx/uid_map) and the inside UID range of a user namespace (the 1st and 3rd
517	* columns in /proc/xxx/uid_map), translates the given UID from the outside range to the inside
518	* range. For example, given the following UID range:
519	*
520	* 0 1000 1
521	*
522	* calling uid_range_translate(outside, inside, 1000) will return 0 as the output UID. Alternatively,
523	* calling uid_range_translate(inside, outside, 0) will return 1000 as the output UID.
524	*/
525
526	for (size_t i = 0; i < uid_range_entries(outside); i++)	464✔
527	assert(outside->entries[i].nr == inside->entries[i].nr);	250✔
528
529	for (size_t i = 0; i < uid_range_entries(outside); i++) {	250✔
530	const UIDRangeEntry *e = outside->entries + i;	240✔
531
532	if (uid < e->start \|\| uid >= e->start + e->nr)	240✔
533	continue;	36✔
534
535	*ret = inside->entries[i].start + uid - e->start;	204✔
536	return 0;	204✔
537	}
538
539	return -ESRCH;
540	}
541
542	int uid_range_translate_userns_fd(int userns_fd, UIDRangeUsernsMode mode, uid_t uid, uid_t *ret) {	2✔
543	int r;	2✔
544
545	assert(userns_fd >= 0);	2✔
546	assert(IN_SET(mode, UID_RANGE_USERNS_OUTSIDE, GID_RANGE_USERNS_OUTSIDE));	2✔
547
548	_cleanup_(uid_range_freep) UIDRange *outside_range = NULL;	2✔
549	r = uid_range_load_userns_by_fd_full(userns_fd, mode, /* coalesce= */ false, &outside_range);	2✔
550	if (r < 0)	2✔
551	return r;
552
553	mode = mode == UID_RANGE_USERNS_OUTSIDE ? UID_RANGE_USERNS_INSIDE : GID_RANGE_USERNS_INSIDE;	2✔
554
555	_cleanup_(uid_range_freep) UIDRange *inside_range = NULL;	2✔
556	r = uid_range_load_userns_by_fd_full(userns_fd, mode, /* coalesce= */ false, &inside_range);	2✔
557	if (r < 0)	2✔
558	return r;
559
560	return uid_range_translate(outside_range, inside_range, uid, ret);	2✔
561	}
562
563	bool uid_range_equal(const UIDRange a, const UIDRange b) {	6✔
564	if (a == b)	6✔
565	return true;
566
567	if (!a \|\| !b)	6✔
568	return false;
569
570	if (a->n_entries != b->n_entries)	5✔
571	return false;
572
573	for (size_t i = 0; i < a->n_entries; i++) {	8✔
574	if (a->entries[i].start != b->entries[i].start)	5✔
575	return false;
576	if (a->entries[i].nr != b->entries[i].nr)	5✔
577	return false;
578	}
579
580	return true;
581	}
582
583	int uid_map_search_root(pid_t pid, UIDRangeUsernsMode mode, uid_t *ret) {	63✔
584	int r;	63✔
585
586	assert(pid_is_valid(pid));	63✔
587	assert(IN_SET(mode, UID_RANGE_USERNS_OUTSIDE, GID_RANGE_USERNS_OUTSIDE));	63✔
588
589	const char *p = procfs_file_alloca(pid, mode == UID_RANGE_USERNS_OUTSIDE ? "uid_map" : "gid_map");	63✔
590	_cleanup_fclose_ FILE *f = fopen(p, "re");	126✔
591	if (!f) {	63✔
592	if (errno != ENOENT)	×
593	return -errno;	×
594
UNCOV 595	r = proc_mounted();	×
596	if (r < 0)	×
597	return -ENOENT; /* original error, if we can't determine /proc/ state */
598
599	return r ? -ENOPKG : -ENOSYS;	×
600	}
601
UNCOV 602	for (;;) {	×
603	uid_t uid_base = UID_INVALID, uid_shift = UID_INVALID;	63✔
604
605	r = uid_map_read_one(f, &uid_base, &uid_shift, /* ret_range= */ NULL);	63✔
606	if (r < 0)	63✔
607	return r;	63✔
608
609	if (uid_base == 0) {	62✔
610	if (ret)	62✔
611	*ret = uid_shift;	62✔
612	return 0;	62✔
613	}
614	}
615	}
616
617	uid_t uid_range_base(const UIDRange *range) {	8✔
618
619	/* Returns the lowest UID in the range (notw that elements are sorted, hence we just need to look at
620	* the first one that is populated. */
621
622	if (uid_range_is_empty(range))	8✔
623	return UID_INVALID;
624
625	FOREACH_ARRAY(e, range->entries, range->n_entries)	8✔
626	if (e->nr > 0)	8✔
627	return e->start;	8✔
628
629	return UID_INVALID;
630	}

systemd / systemd / 24165447443

Source File Press 'n' to go to next uncovered line, 'b' for previous

Source File
Press 'n' to go to next uncovered line, 'b' for previous