#include <stdio.h>
#include "commonio.h"
#include "subordinateio.h"
+#include <sys/types.h>
+#include <pwd.h>
struct subordinate_range {
const char *owner;
#define NFIELDS 3
+/*
+ * subordinate_dup: create a duplicate range
+ *
+ * @ent: a pointer to a subordinate_range struct
+ *
+ * Returns a pointer to a newly allocated duplicate subordinate_range struct
+ * or NULL on failure
+ */
static /*@null@*/ /*@only@*/void *subordinate_dup (const void *ent)
{
const struct subordinate_range *rangeent = ent;
return range;
}
+/*
+ * subordinate_free: free a subordinate_range struct
+ *
+ * @ent: pointer to a subordinate_range struct to free.
+ */
static void subordinate_free (/*@out@*/ /*@only@*/void *ent)
{
struct subordinate_range *rangeent = ent;
free (rangeent);
}
+/*
+ * subordinate_parse:
+ *
+ * @line: a line to parse
+ *
+ * Returns a pointer to a subordinate_range struct representing the values
+ * in @line, or NULL on failure. Note that the returned value should not
+ * be freed by the caller.
+ */
static void *subordinate_parse (const char *line)
{
static struct subordinate_range range;
return ⦥
}
+/*
+ * subordinate_put: print a subordinate_range value to a file
+ *
+ * @ent: a pointer to a subordinate_range struct to print out.
+ * @file: file to which to print.
+ *
+ * Returns 0 on success, -1 on error.
+ */
static int subordinate_put (const void *ent, FILE * file)
{
const struct subordinate_range *range = ent;
NULL, /* close_hook */
};
-static /*@observer@*/ /*@null*/const struct subordinate_range *subordinate_next(struct commonio_db *db)
-{
- commonio_next (db);
-}
-
-static bool is_range_free(struct commonio_db *db, unsigned long start,
- unsigned long count)
-{
- const struct subordinate_range *range;
- unsigned long end = start + count - 1;
-
- commonio_rewind(db);
- while ((range = commonio_next(db)) != NULL) {
- unsigned long first = range->start;
- unsigned long last = first + range->count - 1;
-
- if ((end >= first) && (start <= last))
- return false;
- }
- return true;
-}
-
+/*
+ * range_exists: Check whether @owner owns any ranges
+ *
+ * @db: database to query
+ * @owner: owner being queried
+ *
+ * Returns true if @owner owns any subuid ranges, false otherwise.
+ */
static const bool range_exists(struct commonio_db *db, const char *owner)
{
const struct subordinate_range *range;
return false;
}
+/*
+ * find_range: find a range which @owner is authorized to use which includes
+ * subuid @val.
+ *
+ * @db: database to query
+ * @owner: owning uid being queried
+ * @val: subuid being searched for.
+ *
+ * Returns a range of subuids belonging to @owner and including the subuid
+ * @val, or NULL if no such range exists.
+ */
static const struct subordinate_range *find_range(struct commonio_db *db,
const char *owner, unsigned long val)
{
const struct subordinate_range *range;
+
+ /*
+ * Search for exact username/group specification
+ *
+ * This is the original method - go fast through the db, doing only
+ * exact username/group string comparison. Therefore we leave it as-is
+ * for the time being, in order to keep it equally fast as it was
+ * before.
+ */
commonio_rewind(db);
while ((range = commonio_next(db)) != NULL) {
unsigned long first = range->start;
if ((val >= first) && (val <= last))
return range;
}
+
+
+ /*
+ * We only do special handling for these two files
+ */
+ if ((0 != strcmp(db->filename, "/etc/subuid")) && (0 != strcmp(db->filename, "/etc/subgid")))
+ return NULL;
+
+ /*
+ * Search loop above did not produce any result. Let's rerun it,
+ * but this time try to match actual UIDs. The first entry that
+ * matches is considered a success.
+ * (It may be specified as literal UID or as another username which
+ * has the same UID as the username we are looking for.)
+ */
+ struct passwd *pwd;
+ uid_t owner_uid;
+ char owner_uid_string[33] = "";
+
+
+ /* Get UID of the username we are looking for */
+ pwd = getpwnam(owner);
+ if (NULL == pwd) {
+ /* Username not defined in /etc/passwd, or error occured during lookup */
+ return NULL;
+ }
+ owner_uid = pwd->pw_uid;
+ sprintf(owner_uid_string, "%lu", (unsigned long int)owner_uid);
+
+ commonio_rewind(db);
+ while ((range = commonio_next(db)) != NULL) {
+ unsigned long first = range->start;
+ unsigned long last = first + range->count - 1;
+
+ /* For performance reasons check range before using getpwnam() */
+ if ((val < first) || (val > last)) {
+ continue;
+ }
+
+ /*
+ * Range matches. Check if range owner is specified
+ * as numeric UID and if it matches.
+ */
+ if (0 == strcmp(range->owner, owner_uid_string)) {
+ return range;
+ }
+
+ /*
+ * Ok, this range owner is not specified as numeric UID
+ * we are looking for. It may be specified as another
+ * UID or as a literal username.
+ *
+ * If specified as another UID, the call to getpwnam()
+ * will return NULL.
+ *
+ * If specified as literal username, we will get its
+ * UID and compare that to UID we are looking for.
+ */
+ const struct passwd *range_owner_pwd;
+
+ range_owner_pwd = getpwnam(range->owner);
+ if (NULL == range_owner_pwd) {
+ continue;
+ }
+
+ if (owner_uid == range_owner_pwd->pw_uid) {
+ return range;
+ }
+ }
+
return NULL;
}
+/*
+ * have_range: check whether @owner is authorized to use the range
+ * (@start .. @start+@count-1).
+ * @db: database to check
+ * @owner: owning uid being queried
+ * @start: start of range
+ * @count: number of uids in range
+ *
+ * Returns true if @owner is authorized to use the range, false otherwise.
+ */
static bool have_range(struct commonio_db *db,
const char *owner, unsigned long start, unsigned long count)
{
return false;
}
+/*
+ * subordinate_range_cmp: compare uid ranges
+ *
+ * @p1: pointer to a commonio_entry struct to compare
+ * @p2: pointer to second commonio_entry struct to compare
+ *
+ * Returns 0 if the entries are the same. Otherwise return -1
+ * if the range in p1 is lower than that in p2, or (if the ranges are
+ * equal) if the owning uid in p1 is lower than p2's. Return 1 if p1's
+ * range or owning uid is great than p2's.
+ */
static int subordinate_range_cmp (const void *p1, const void *p2)
{
struct subordinate_range *range1, *range2;
return strcmp(range1->owner, range2->owner);
}
+/*
+ * find_free_range: find an unused consecutive sequence of ids to allocate
+ * to a user.
+ * @db: database to search
+ * @min: the first uid in the range to find
+ * @max: the highest uid to find
+ * @count: the number of uids needed
+ *
+ * Return the lowest new uid, or ULONG_MAX on failure.
+ */
static unsigned long find_free_range(struct commonio_db *db,
unsigned long min, unsigned long max,
unsigned long count)
unsigned long low, high;
/* When given invalid parameters fail */
- if ((count == 0) || (max <= min))
+ if ((count == 0) || (max < min))
goto fail;
/* Sort by range then by owner */
/* Find the top end of the hole before this range */
high = first;
- if (high > max)
- high = max;
+
+ /* Don't allocate IDs after max (included) */
+ if (high > max + 1) {
+ high = max + 1;
+ }
/* Is the hole before this range large enough? */
- if ((high > low) && (((high - low) + 1) >= count))
+ if ((high > low) && ((high - low) >= count))
return low;
/* Compute the low end of the next hole */
return ULONG_MAX;
}
+/*
+ * add_range: add a subuid range to an owning uid's list of authorized
+ * subuids.
+ * @db: database to which to add
+ * @owner: uid which owns the subuid
+ * @start: the first uid in the owned range
+ * @count: the number of uids in the range
+ *
+ * Return 1 if the range is already present or on success. On error
+ * return 0 and set errno appropriately.
+ */
static int add_range(struct commonio_db *db,
const char *owner, unsigned long start, unsigned long count)
{
return commonio_append(db, &range);
}
-static int remove_range(struct commonio_db *db,
- const char *owner, unsigned long start, unsigned long count)
+/*
+ * remove_range: remove a range of subuids from an owning uid's list
+ * of authorized subuids.
+ * @db: database to work on
+ * @owner: owning uid whose range is being removed
+ * @start: start of the range to be removed
+ * @count: number of uids in the range.
+ *
+ * Returns 0 on failure, 1 on success. Failure means that we needed to
+ * create a new range to represent the new limits, and failed doing so.
+ */
+static int remove_range (struct commonio_db *db,
+ const char *owner,
+ unsigned long start, unsigned long count)
{
struct commonio_entry *ent;
unsigned long end;
- if (count == 0)
+ if (count == 0) {
return 1;
+ }
end = start + count - 1;
- for (ent = db->head; ent; ent = ent->next) {
+ for (ent = db->head; NULL != ent; ent = ent->next) {
struct subordinate_range *range = ent->eptr;
unsigned long first;
unsigned long last;
/* Skip unparsed entries */
- if (!range)
+ if (NULL == range) {
continue;
+ }
first = range->start;
last = first + range->count - 1;
/* Skip entries with a different owner */
- if (0 != strcmp(range->owner, owner))
+ if (0 != strcmp (range->owner, owner)) {
continue;
+ }
/* Skip entries outside of the range to remove */
- if ((end < first) || (start > last))
+ if ((end < first) || (start > last)) {
continue;
-
- /* Is entry completely contained in the range to remove? */
- if ((start <= first) && (end >= last)) {
- commonio_del_entry (db, ent);
- }
- /* Is just the start of the entry removed? */
- else if ((start <= first) && (end < last)) {
- range->start = end + 1;
- range->count = (last - range->start) + 1;
-
- ent->changed = true;
- db->changed = true;
}
- /* Is just the end of the entry removed? */
- else if ((start > first) && (end >= last)) {
- range->count = (start - range->start) + 1;
-
- ent->changed = true;
- db->changed = true;
- }
- /* The middle of the range is removed */
- else {
- struct subordinate_range tail;
- tail.owner = range->owner;
- tail.start = end + 1;
- tail.count = (last - tail.start) + 1;
-
- if (!commonio_append(db, &tail))
- return 0;
-
- range->count = (start - range->start) + 1;
- ent->changed = true;
- db->changed = true;
+ if (start <= first) {
+ if (end >= last) {
+ /* to be removed: [start, end]
+ * range: [first, last] */
+ /* entry completely contained in the
+ * range to remove */
+ commonio_del_entry (db, ent);
+ } else {
+ /* to be removed: [start, end]
+ * range: [first, last] */
+ /* Remove only the start of the entry */
+ range->start = end + 1;
+ range->count = (last - range->start) + 1;
+
+ ent->changed = true;
+ db->changed = true;
+ }
+ } else {
+ if (end >= last) {
+ /* to be removed: [start, end]
+ * range: [first, last] */
+ /* Remove only the end of the entry */
+ range->count = start - range->start;
+
+ ent->changed = true;
+ db->changed = true;
+ } else {
+ /* to be removed: [start, end]
+ * range: [first, last] */
+ /* Remove the middle of the range
+ * This requires to create a new range */
+ struct subordinate_range tail;
+ tail.owner = range->owner;
+ tail.start = end + 1;
+ tail.count = (last - tail.start) + 1;
+
+ if (commonio_append (db, &tail) == 0) {
+ return 0;
+ }
+
+ range->count = start - range->start;
+
+ ent->changed = true;
+ db->changed = true;
+ }
}
}
#ifdef WITH_SELINUX
NULL, /* scontext */
#endif
+ 0644, /* st_mode */
+ 0, /* st_uid */
+ 0, /* st_gid */
NULL, /* head */
NULL, /* tail */
NULL, /* cursor */
false, /* changed */
false, /* isopen */
false, /* locked */
- false /* readonly */
+ false, /* readonly */
+ false /* setname */
};
int sub_uid_setdbname (const char *filename)
return commonio_open (&subordinate_uid_db, mode);
}
-bool is_sub_uid_range_free(uid_t start, unsigned long count)
-{
- return is_range_free (&subordinate_uid_db, start, count);
-}
-
bool sub_uid_assigned(const char *owner)
{
return range_exists (&subordinate_uid_db, owner);
#ifdef WITH_SELINUX
NULL, /* scontext */
#endif
+ 0644, /* st_mode */
+ 0, /* st_uid */
+ 0, /* st_gid */
NULL, /* head */
NULL, /* tail */
NULL, /* cursor */
false, /* changed */
false, /* isopen */
false, /* locked */
- false /* readonly */
+ false, /* readonly */
+ false /* setname */
};
int sub_gid_setdbname (const char *filename)
return commonio_open (&subordinate_gid_db, mode);
}
-bool is_sub_gid_range_free(gid_t start, unsigned long count)
-{
- return is_range_free (&subordinate_gid_db, start, count);
-}
-
bool have_sub_gids(const char *owner, gid_t start, unsigned long count)
{
return have_range(&subordinate_gid_db, owner, start, count);
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