Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 478 insertions, 0 deletions

diff --git a/src/nss-systemd/userdb-glue.c b/src/nss-systemd/userdb-glue.c
new file mode 100644
index 0000000..c69667d
--- /dev/null
+++ b/src/nss-systemd/userdb-glue.c
@@ -0,0 +1,478 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "env-util.h"
+#include "fd-util.h"
+#include "nss-systemd.h"
+#include "strv.h"
+#include "user-record-nss.h"
+#include "user-record.h"
+#include "user-util.h"
+#include "userdb-glue.h"
+#include "userdb.h"
+
+UserDBFlags nss_glue_userdb_flags(void) {
+        UserDBFlags flags = USERDB_EXCLUDE_NSS;
+
+        /* Make sure that we don't go in circles when allocating a dynamic UID by checking our own database */
+        if (getenv_bool_secure("SYSTEMD_NSS_DYNAMIC_BYPASS") > 0)
+                flags |= USERDB_EXCLUDE_DYNAMIC_USER;
+
+        return flags;
+}
+
+int nss_pack_user_record(
+                UserRecord *hr,
+                struct passwd *pwd,
+                char *buffer,
+                size_t buflen) {
+
+        const char *rn, *hd, *shell;
+        size_t required;
+
+        assert(hr);
+        assert(pwd);
+
+        assert(hr->user_name);
+        required = strlen(hr->user_name) + 1;
+
+        required += 2; /* strlen(PASSWORD_SEE_SHADOW) + 1 */
+
+        assert_se(rn = user_record_real_name(hr));
+        required += strlen(rn) + 1;
+
+        assert_se(hd = user_record_home_directory(hr));
+        required += strlen(hd) + 1;
+
+        assert_se(shell = user_record_shell(hr));
+        required += strlen(shell) + 1;
+
+        if (buflen < required)
+                return -ERANGE;
+
+        *pwd = (struct passwd) {
+                .pw_name = buffer,
+                .pw_uid = hr->uid,
+                .pw_gid = user_record_gid(hr),
+        };
+
+        assert(buffer);
+
+        pwd->pw_passwd = stpcpy(pwd->pw_name, hr->user_name) + 1;
+        pwd->pw_gecos = stpcpy(pwd->pw_passwd, PASSWORD_SEE_SHADOW) + 1;
+        pwd->pw_dir = stpcpy(pwd->pw_gecos, rn) + 1;
+        pwd->pw_shell = stpcpy(pwd->pw_dir, hd) + 1;
+        strcpy(pwd->pw_shell, shell);
+
+        return 0;
+}
+
+enum nss_status userdb_getpwnam(
+                const char *name,
+                struct passwd *pwd,
+                char *buffer, size_t buflen,
+                int *errnop) {
+
+        _cleanup_(user_record_unrefp) UserRecord *hr = NULL;
+        int r;
+
+        assert(pwd);
+        assert(errnop);
+
+        if (_nss_systemd_is_blocked())
+                return NSS_STATUS_NOTFOUND;
+
+        r = userdb_by_name(name, nss_glue_userdb_flags()|USERDB_SUPPRESS_SHADOW, &hr);
+        if (r == -ESRCH)
+                return NSS_STATUS_NOTFOUND;
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        r = nss_pack_user_record(hr, pwd, buffer, buflen);
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        return NSS_STATUS_SUCCESS;
+}
+
+enum nss_status userdb_getpwuid(
+                uid_t uid,
+                struct passwd *pwd,
+                char *buffer,
+                size_t buflen,
+                int *errnop) {
+
+        _cleanup_(user_record_unrefp) UserRecord *hr = NULL;
+        int r;
+
+        assert(pwd);
+        assert(errnop);
+
+        if (_nss_systemd_is_blocked())
+                return NSS_STATUS_NOTFOUND;
+
+        r = userdb_by_uid(uid, nss_glue_userdb_flags()|USERDB_SUPPRESS_SHADOW, &hr);
+        if (r == -ESRCH)
+                return NSS_STATUS_NOTFOUND;
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        r = nss_pack_user_record(hr, pwd, buffer, buflen);
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        return NSS_STATUS_SUCCESS;
+}
+
+int nss_pack_user_record_shadow(
+                UserRecord *hr,
+                struct spwd *spwd,
+                char *buffer,
+                size_t buflen) {
+
+        const char *hashed;
+        size_t required;
+
+        assert(hr);
+        assert(spwd);
+
+        assert(hr->user_name);
+        required = strlen(hr->user_name) + 1;
+
+        assert_se(hashed = strv_isempty(hr->hashed_password) ? PASSWORD_LOCKED_AND_INVALID : hr->hashed_password[0]);
+        required += strlen(hashed) + 1;
+
+        if (buflen < required)
+                return -ERANGE;
+
+        *spwd = (struct spwd) {
+                .sp_namp = buffer,
+                .sp_lstchg = hr->last_password_change_usec == 0 ? 1 :               /* map 0 to 1, since 0 means please change password on next login */
+                             hr->last_password_change_usec == UINT64_MAX ? -1 :
+                             (long int) (hr->last_password_change_usec / USEC_PER_DAY),
+                .sp_min = hr->password_change_min_usec != UINT64_MAX ? (long int) (hr->password_change_min_usec / USEC_PER_DAY) : -1,
+                .sp_max = hr->password_change_max_usec != UINT64_MAX ? (long int) (hr->password_change_max_usec / USEC_PER_DAY) : -1,
+                .sp_warn = hr->password_change_warn_usec != UINT64_MAX ? (long int) (hr->password_change_warn_usec / USEC_PER_DAY) : -1,
+                .sp_inact = hr->password_change_inactive_usec != UINT64_MAX ? (long int) (hr->password_change_inactive_usec / USEC_PER_DAY) : -1,
+                .sp_expire = hr->locked > 0 || hr->not_after_usec == 0 ? 1 : /* already expired/locked */
+                             hr->not_after_usec == UINT64_MAX ? -1 :
+                             (long int) (hr->not_after_usec / USEC_PER_DAY),
+                .sp_flag = ULONG_MAX,
+        };
+
+        assert(buffer);
+
+        spwd->sp_pwdp = stpcpy(spwd->sp_namp, hr->user_name) + 1;
+        strcpy(spwd->sp_pwdp, hashed);
+
+        return 0;
+}
+
+enum nss_status userdb_getspnam(
+                const char *name,
+                struct spwd *spwd,
+                char *buffer, size_t buflen,
+                int *errnop) {
+
+        _cleanup_(user_record_unrefp) UserRecord *hr = NULL;
+        int r;
+
+        assert(spwd);
+        assert(errnop);
+
+        if (_nss_systemd_is_blocked())
+                return NSS_STATUS_NOTFOUND;
+
+        r = userdb_by_name(name, nss_glue_userdb_flags(), &hr);
+        if (r == -ESRCH)
+                return NSS_STATUS_NOTFOUND;
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (hr->incomplete) /* protected records missing? */
+                return NSS_STATUS_NOTFOUND;
+
+        r = nss_pack_user_record_shadow(hr, spwd, buffer, buflen);
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        return NSS_STATUS_SUCCESS;
+}
+
+int nss_pack_group_record(
+                GroupRecord *g,
+                char **extra_members,
+                struct group *gr,
+                char *buffer,
+                size_t buflen) {
+
+        char **array = NULL, *p;
+        size_t required, n = 0, i = 0;
+
+        assert(g);
+        assert(gr);
+
+        assert(g->group_name);
+        required = strlen(g->group_name) + 1;
+
+        STRV_FOREACH(m, g->members) {
+                required += sizeof(char*);  /* space for ptr array entry */
+                required += strlen(*m) + 1;
+                n++;
+        }
+        STRV_FOREACH(m, extra_members) {
+                if (strv_contains(g->members, *m))
+                        continue;
+
+                required += sizeof(char*);
+                required += strlen(*m) + 1;
+                n++;
+        }
+
+        required += sizeof(char*); /* trailing NULL in ptr array entry */
+
+        if (buflen < required)
+                return -ERANGE;
+
+        array = (char**) buffer; /* place ptr array at beginning of buffer, under assumption buffer is aligned */
+        p = buffer + sizeof(void*) * (n + 1); /* place member strings right after the ptr array */
+
+        STRV_FOREACH(m, g->members) {
+                array[i++] = p;
+                p = stpcpy(p, *m) + 1;
+        }
+        STRV_FOREACH(m, extra_members) {
+                if (strv_contains(g->members, *m))
+                        continue;
+
+                array[i++] = p;
+                p = stpcpy(p, *m) + 1;
+        }
+
+        assert_se(i == n);
+        array[n] = NULL;
+
+        *gr = (struct group) {
+                .gr_name = strcpy(p, g->group_name),
+                .gr_gid = g->gid,
+                .gr_passwd = (char*) PASSWORD_SEE_SHADOW,
+                .gr_mem = array,
+        };
+
+        return 0;
+}
+
+enum nss_status userdb_getgrnam(
+                const char *name,
+                struct group *gr,
+                char *buffer,
+                size_t buflen,
+                int *errnop) {
+
+        _cleanup_(group_record_unrefp) GroupRecord *g = NULL;
+        _cleanup_strv_free_ char **members = NULL;
+        int r;
+
+        assert(gr);
+        assert(errnop);
+
+        if (_nss_systemd_is_blocked())
+                return NSS_STATUS_NOTFOUND;
+
+        r = groupdb_by_name(name, nss_glue_userdb_flags()|USERDB_SUPPRESS_SHADOW, &g);
+        if (r < 0 && r != -ESRCH) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        r = membershipdb_by_group_strv(name, nss_glue_userdb_flags()|USERDB_SUPPRESS_SHADOW, &members);
+        if (r < 0 && r != -ESRCH) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (!g) {
+                _unused_ _cleanup_(_nss_systemd_unblockp) bool blocked = false;
+
+                if (strv_isempty(members))
+                        return NSS_STATUS_NOTFOUND;
+
+                /* Grmbl, so we are supposed to extend a group entry, but the group entry itself is not
+                 * accessible via non-NSS. Hence let's do what we have to do, and query NSS after all to
+                 * acquire it, so that we can extend it (that's because glibc's group merging feature will
+                 * merge groups only if both GID and name match and thus we need to have both first). It
+                 * sucks behaving recursively likely this, but it's apparently what everybody does. We break
+                 * the recursion for ourselves via the _nss_systemd_block_nss() lock. */
+
+                r = _nss_systemd_block(true);
+                if (r < 0)
+                        return r;
+
+                blocked = true;
+
+                r = nss_group_record_by_name(name, false, &g);
+                if (r == -ESRCH)
+                        return NSS_STATUS_NOTFOUND;
+                if (r < 0) {
+                        *errnop = -r;
+                        return NSS_STATUS_UNAVAIL;
+                }
+        }
+
+        r = nss_pack_group_record(g, members, gr, buffer, buflen);
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        return NSS_STATUS_SUCCESS;
+}
+
+enum nss_status userdb_getgrgid(
+                gid_t gid,
+                struct group *gr,
+                char *buffer,
+                size_t buflen,
+                int *errnop) {
+
+
+        _cleanup_(group_record_unrefp) GroupRecord *g = NULL;
+        _cleanup_strv_free_ char **members = NULL;
+        bool from_nss;
+        int r;
+
+        assert(gr);
+        assert(errnop);
+
+        if (_nss_systemd_is_blocked())
+                return NSS_STATUS_NOTFOUND;
+
+        r = groupdb_by_gid(gid, nss_glue_userdb_flags()|USERDB_SUPPRESS_SHADOW, &g);
+        if (r < 0 && r != -ESRCH) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (!g) {
+                _unused_ _cleanup_(_nss_systemd_unblockp) bool blocked = false;
+
+                /* So, quite possibly we have to extend an existing group record with additional members. But
+                 * to do this we need to know the group name first. The group didn't exist via non-NSS
+                 * queries though, hence let's try to acquire it here recursively via NSS. */
+
+                r = _nss_systemd_block(true);
+                if (r < 0)
+                        return r;
+
+                blocked = true;
+
+                r = nss_group_record_by_gid(gid, false, &g);
+                if (r == -ESRCH)
+                        return NSS_STATUS_NOTFOUND;
+                if (r < 0) {
+                        *errnop = -r;
+                        return NSS_STATUS_UNAVAIL;
+                }
+
+                from_nss = true;
+        } else
+                from_nss = false;
+
+        r = membershipdb_by_group_strv(g->group_name, nss_glue_userdb_flags()|USERDB_SUPPRESS_SHADOW, &members);
+        if (r < 0 && r != -ESRCH) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        /* If we acquired the record via NSS then there's no reason to respond unless we have to augment the
+         * list of members of the group */
+        if (from_nss && strv_isempty(members))
+                return NSS_STATUS_NOTFOUND;
+
+        r = nss_pack_group_record(g, members, gr, buffer, buflen);
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        return NSS_STATUS_SUCCESS;
+}
+
+int nss_pack_group_record_shadow(
+                GroupRecord *hr,
+                struct sgrp *sgrp,
+                char *buffer,
+                size_t buflen) {
+
+        const char *hashed;
+        size_t required;
+
+        assert(hr);
+        assert(sgrp);
+
+        assert(hr->group_name);
+        required = strlen(hr->group_name) + 1;
+
+        assert_se(hashed = strv_isempty(hr->hashed_password) ? PASSWORD_LOCKED_AND_INVALID : hr->hashed_password[0]);
+        required += strlen(hashed) + 1;
+
+        if (buflen < required)
+                return -ERANGE;
+
+        *sgrp = (struct sgrp) {
+                .sg_namp = buffer,
+        };
+
+        assert(buffer);
+
+        sgrp->sg_passwd = stpcpy(sgrp->sg_namp, hr->group_name) + 1;
+        strcpy(sgrp->sg_passwd, hashed);
+
+        return 0;
+}
+
+enum nss_status userdb_getsgnam(
+                const char *name,
+                struct sgrp *sgrp,
+                char *buffer, size_t buflen,
+                int *errnop) {
+
+        _cleanup_(group_record_unrefp) GroupRecord *hr = NULL;
+        int r;
+
+        assert(sgrp);
+        assert(errnop);
+
+        if (_nss_systemd_is_blocked())
+                return NSS_STATUS_NOTFOUND;
+
+        r = groupdb_by_name(name, nss_glue_userdb_flags(), &hr);
+        if (r == -ESRCH)
+                return NSS_STATUS_NOTFOUND;
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_UNAVAIL;
+        }
+
+        if (hr->incomplete) /* protected records missing? */
+                return NSS_STATUS_NOTFOUND;
+
+        r = nss_pack_group_record_shadow(hr, sgrp, buffer, buflen);
+        if (r < 0) {
+                *errnop = -r;
+                return NSS_STATUS_TRYAGAIN;
+        }
+
+        return NSS_STATUS_SUCCESS;
+}