shared: add helpers for converting NSS passwd/group structures to new JSON objects

These new calls may be used to convert classic UNIX/glibc NSS struct
passwd and struct group records into new-style JSON-based user/group
objects.

5 files changed, 525 insertions, 0 deletions

diff --git a/src/shared/group-record-nss.c b/src/shared/group-record-nss.c
new file mode 100644
index 0000000000..77924f1c40
--- /dev/null
+++ b/src/shared/group-record-nss.c
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "errno-util.h"
+#include "group-record-nss.h"
+#include "libcrypt-util.h"
+#include "strv.h"
+
+int nss_group_to_group_record(
+                const struct group *grp,
+                const struct sgrp *sgrp,
+                GroupRecord **ret) {
+
+        _cleanup_(group_record_unrefp) GroupRecord *g = NULL;
+        int r;
+
+        assert(grp);
+        assert(ret);
+
+        if (isempty(grp->gr_name))
+                return -EINVAL;
+
+        if (sgrp && !streq_ptr(sgrp->sg_namp, grp->gr_name))
+                return -EINVAL;
+
+        g = group_record_new();
+        if (!g)
+                return -ENOMEM;
+
+        g->group_name = strdup(grp->gr_name);
+        if (!g->group_name)
+                return -ENOMEM;
+
+        g->members = strv_copy(grp->gr_mem);
+        if (!g->members)
+                return -ENOMEM;
+
+        g->gid = grp->gr_gid;
+
+        if (sgrp) {
+                if (hashed_password_valid(sgrp->sg_passwd)) {
+                        g->hashed_password = strv_new(sgrp->sg_passwd);
+                        if (!g->hashed_password)
+                                return -ENOMEM;
+                }
+
+                r = strv_extend_strv(&g->members, sgrp->sg_mem, 1);
+                if (r < 0)
+                        return r;
+
+                g->administrators = strv_copy(sgrp->sg_adm);
+                if (!g->administrators)
+                        return -ENOMEM;
+        }
+
+        r = json_build(&g->json, JSON_BUILD_OBJECT(
+                                       JSON_BUILD_PAIR("groupName", JSON_BUILD_STRING(g->group_name)),
+                                       JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(g->gid)),
+                                       JSON_BUILD_PAIR_CONDITION(!strv_isempty(g->members), "members", JSON_BUILD_STRV(g->members)),
+                                       JSON_BUILD_PAIR_CONDITION(!strv_isempty(g->hashed_password), "privileged", JSON_BUILD_OBJECT(JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRV(g->hashed_password)))),
+                                       JSON_BUILD_PAIR_CONDITION(!strv_isempty(g->administrators), "administrators", JSON_BUILD_STRV(g->administrators))));
+        if (r < 0)
+                return r;
+
+        g->mask = USER_RECORD_REGULAR |
+                (!strv_isempty(g->hashed_password) ? USER_RECORD_PRIVILEGED : 0);
+
+        *ret = TAKE_PTR(g);
+        return 0;
+}
+
+int nss_sgrp_for_group(const struct group *grp, struct sgrp *ret_sgrp, char **ret_buffer) {
+        size_t buflen = 4096;
+        int r;
+
+        assert(grp);
+        assert(ret_sgrp);
+        assert(ret_buffer);
+
+        for (;;) {
+                _cleanup_free_ char *buf = NULL;
+                struct sgrp sgrp, *result;
+
+                buf = malloc(buflen);
+                if (!buf)
+                        return -ENOMEM;
+
+                r = getsgnam_r(grp->gr_name, &sgrp, buf, buflen, &result);
+                if (r == 0) {
+                        if (!result)
+                                return -ESRCH;
+
+                        *ret_sgrp = *result;
+                        *ret_buffer = TAKE_PTR(buf);
+                        return 0;
+                }
+                if (r < 0)
+                        return -EIO; /* Weird, this should not return negative! */
+                if (r != ERANGE)
+                        return -r;
+
+                if (buflen > SIZE_MAX / 2)
+                        return -ERANGE;
+
+                buflen *= 2;
+                buf = mfree(buf);
+        }
+}
+
+int nss_group_record_by_name(const char *name, GroupRecord **ret) {
+        _cleanup_free_ char *buf = NULL, *sbuf = NULL;
+        struct group grp, *result;
+        bool incomplete = false;
+        size_t buflen = 4096;
+        struct sgrp sgrp;
+        int r;
+
+        assert(name);
+        assert(ret);
+
+        for (;;) {
+                buf = malloc(buflen);
+                if (!buf)
+                        return -ENOMEM;
+
+                r = getgrnam_r(name, &grp, buf, buflen, &result);
+                if (r == 0)  {
+                        if (!result)
+                                return -ESRCH;
+
+                        break;
+                }
+
+                if (r < 0)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EIO), "getgrnam_r() returned a negative value");
+                if (r != ERANGE)
+                        return -r;
+                if (buflen > SIZE_MAX / 2)
+                        return -ERANGE;
+
+                buflen *= 2;
+                buf = mfree(buf);
+        }
+
+        r = nss_sgrp_for_group(result, &sgrp, &sbuf);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to do shadow lookup for group %s, ignoring: %m", result->gr_name);
+                incomplete = ERRNO_IS_PRIVILEGE(r);
+        }
+
+        r = nss_group_to_group_record(result, r >= 0 ? &sgrp : NULL, ret);
+        if (r < 0)
+                return r;
+
+        (*ret)->incomplete = incomplete;
+        return 0;
+}
+
+int nss_group_record_by_gid(gid_t gid, GroupRecord **ret) {
+        _cleanup_free_ char *buf = NULL, *sbuf = NULL;
+        struct group grp, *result;
+        bool incomplete = false;
+        size_t buflen = 4096;
+        struct sgrp sgrp;
+        int r;
+
+        assert(ret);
+
+        for (;;) {
+                buf = malloc(buflen);
+                if (!buf)
+                        return -ENOMEM;
+
+                r = getgrgid_r(gid, &grp, buf, buflen, &result);
+                if (r == 0)  {
+                        if (!result)
+                                return -ESRCH;
+                        break;
+                }
+
+                if (r < 0)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EIO), "getgrgid_r() returned a negative value");
+                if (r != ERANGE)
+                        return -r;
+                if (buflen > SIZE_MAX / 2)
+                        return -ERANGE;
+
+                buflen *= 2;
+                buf = mfree(buf);
+        }
+
+        r = nss_sgrp_for_group(result, &sgrp, &sbuf);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to do shadow lookup for group %s, ignoring: %m", result->gr_name);
+                incomplete = ERRNO_IS_PRIVILEGE(r);
+        }
+
+        r = nss_group_to_group_record(result, r >= 0 ? &sgrp : NULL, ret);
+        if (r < 0)
+                return r;
+
+        (*ret)->incomplete = incomplete;
+        return 0;
+}
diff --git a/src/shared/group-record-nss.h b/src/shared/group-record-nss.h
new file mode 100644
index 0000000000..38b2995178
--- /dev/null
+++ b/src/shared/group-record-nss.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <grp.h>
+#include <gshadow.h>
+
+#include "group-record.h"
+
+/* Synthesize GroupRecord objects from NSS data */
+
+int nss_group_to_group_record(const struct group *grp, const struct sgrp *sgrp, GroupRecord **ret);
+int nss_sgrp_for_group(const struct group *grp, struct sgrp *ret_sgrp, char **ret_buffer);
+
+int nss_group_record_by_name(const char *name, GroupRecord **ret);
+int nss_group_record_by_gid(gid_t gid, GroupRecord **ret);
diff --git a/src/shared/meson.build b/src/shared/meson.build
index f9799fee1d..d99aaa62c6 100644
--- a/src/shared/meson.build
+++ b/src/shared/meson.build
@@ -86,6 +86,8 @@ shared_sources = files('''
         generator.c
         generator.h
         gpt.h
+        group-record-nss.c
+        group-record-nss.h
         group-record.c
         group-record.h
         id128-print.c
@@ -191,6 +193,8 @@ shared_sources = files('''
         uid-range.h
         unit-file.c
         unit-file.h
+        user-record-nss.c
+        user-record-nss.h
         user-record.c
         user-record.h
         utmp-wtmp.h
diff --git a/src/shared/user-record-nss.c b/src/shared/user-record-nss.c
new file mode 100644
index 0000000000..11c085d63d
--- /dev/null
+++ b/src/shared/user-record-nss.c
@@ -0,0 +1,288 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "errno-util.h"
+#include "format-util.h"
+#include "libcrypt-util.h"
+#include "strv.h"
+#include "user-record-nss.h"
+
+int nss_passwd_to_user_record(
+                const struct passwd *pwd,
+                const struct spwd *spwd,
+                UserRecord **ret) {
+
+        _cleanup_(user_record_unrefp) UserRecord *hr = NULL;
+        int r;
+
+        assert(pwd);
+        assert(ret);
+
+        if (isempty(pwd->pw_name))
+                return -EINVAL;
+
+        if (spwd && !streq_ptr(spwd->sp_namp, pwd->pw_name))
+                return -EINVAL;
+
+        hr = user_record_new();
+        if (!hr)
+                return -ENOMEM;
+
+        r = free_and_strdup(&hr->user_name, pwd->pw_name);
+        if (r < 0)
+                return r;
+
+        if (isempty(pwd->pw_gecos) || streq_ptr(pwd->pw_gecos, hr->user_name))
+                hr->real_name = mfree(hr->real_name);
+        else {
+                r = free_and_strdup(&hr->real_name, pwd->pw_gecos);
+                if (r < 0)
+                        return r;
+        }
+
+        if (isempty(pwd->pw_dir))
+                hr->home_directory = mfree(hr->home_directory);
+        else {
+                r = free_and_strdup(&hr->home_directory, pwd->pw_dir);
+                if (r < 0)
+                        return r;
+        }
+
+        if (isempty(pwd->pw_shell))
+                hr->shell = mfree(hr->shell);
+        else {
+                r = free_and_strdup(&hr->shell, pwd->pw_shell);
+                if (r < 0)
+                        return r;
+        }
+
+        hr->uid = pwd->pw_uid;
+        hr->gid = pwd->pw_gid;
+
+        if (spwd) {
+                if (hashed_password_valid(spwd->sp_pwdp)) {
+                        strv_free_erase(hr->hashed_password);
+                        hr->hashed_password = strv_new(spwd->sp_pwdp);
+                        if (!hr->hashed_password)
+                                return -ENOMEM;
+                } else
+                        hr->hashed_password = strv_free_erase(hr->hashed_password);
+
+                /* shadow-utils suggests using "chage -E 0" (or -E 1, depending on which man page you check)
+                 * for locking a whole account, hence check for that. Note that it also defines a way to lock
+                 * just a password instead of the whole account, but that's mostly pointless in times of
+                 * password-less authorization, hence let's not bother. */
+
+                if (spwd->sp_expire >= 0)
+                        hr->locked = spwd->sp_expire <= 1;
+                else
+                        hr->locked = -1;
+
+                if (spwd->sp_expire > 1 && (uint64_t) spwd->sp_expire < (UINT64_MAX-1)/USEC_PER_DAY)
+                        hr->not_after_usec = spwd->sp_expire * USEC_PER_DAY;
+                else
+                        hr->not_after_usec = UINT64_MAX;
+
+                if (spwd->sp_lstchg >= 0)
+                        hr->password_change_now = spwd->sp_lstchg == 0;
+                else
+                        hr->password_change_now = -1;
+
+                if (spwd->sp_lstchg > 0 && (uint64_t) spwd->sp_lstchg <= (UINT64_MAX-1)/USEC_PER_DAY)
+                        hr->last_password_change_usec = spwd->sp_lstchg * USEC_PER_DAY;
+                else
+                        hr->last_password_change_usec = UINT64_MAX;
+
+                if (spwd->sp_min > 0 && (uint64_t) spwd->sp_min <= (UINT64_MAX-1)/USEC_PER_DAY)
+                        hr->password_change_min_usec = spwd->sp_min * USEC_PER_DAY;
+                else
+                        hr->password_change_min_usec = UINT64_MAX;
+
+                if (spwd->sp_max > 0 && (uint64_t) spwd->sp_max <= (UINT64_MAX-1)/USEC_PER_DAY)
+                        hr->password_change_max_usec = spwd->sp_max * USEC_PER_DAY;
+                else
+                        hr->password_change_max_usec = UINT64_MAX;
+
+                if (spwd->sp_warn > 0 && (uint64_t) spwd->sp_warn <= (UINT64_MAX-1)/USEC_PER_DAY)
+                        hr->password_change_warn_usec = spwd->sp_warn * USEC_PER_DAY;
+                else
+                        hr->password_change_warn_usec = UINT64_MAX;
+
+                if (spwd->sp_inact > 0 && (uint64_t) spwd->sp_inact <= (UINT64_MAX-1)/USEC_PER_DAY)
+                        hr->password_change_inactive_usec = spwd->sp_inact * USEC_PER_DAY;
+                else
+                        hr->password_change_inactive_usec = UINT64_MAX;
+        } else {
+                hr->hashed_password = strv_free_erase(hr->hashed_password);
+                hr->locked = -1;
+                hr->not_after_usec = UINT64_MAX;
+                hr->password_change_now = -1,
+                hr->last_password_change_usec = UINT64_MAX;
+                hr->password_change_min_usec = UINT64_MAX;
+                hr->password_change_max_usec = UINT64_MAX;
+                hr->password_change_warn_usec = UINT64_MAX;
+                hr->password_change_inactive_usec = UINT64_MAX;
+        }
+
+        hr->json = json_variant_unref(hr->json);
+        r = json_build(&hr->json, JSON_BUILD_OBJECT(
+                                       JSON_BUILD_PAIR("userName", JSON_BUILD_STRING(hr->user_name)),
+                                       JSON_BUILD_PAIR("uid", JSON_BUILD_UNSIGNED(hr->uid)),
+                                       JSON_BUILD_PAIR("gid", JSON_BUILD_UNSIGNED(hr->gid)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->real_name, "realName", JSON_BUILD_STRING(hr->real_name)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->home_directory, "homeDirectory", JSON_BUILD_STRING(hr->home_directory)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->shell, "shell", JSON_BUILD_STRING(hr->shell)),
+                                       JSON_BUILD_PAIR_CONDITION(!strv_isempty(hr->hashed_password), "privileged", JSON_BUILD_OBJECT(JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRV(hr->hashed_password)))),
+                                       JSON_BUILD_PAIR_CONDITION(hr->locked >= 0, "locked", JSON_BUILD_BOOLEAN(hr->locked)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->not_after_usec != UINT64_MAX, "notAfterUSec", JSON_BUILD_UNSIGNED(hr->not_after_usec)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->password_change_now >= 0, "passwordChangeNow", JSON_BUILD_BOOLEAN(hr->password_change_now)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->last_password_change_usec != UINT64_MAX, "lastPasswordChangeUSec", JSON_BUILD_UNSIGNED(hr->last_password_change_usec)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->password_change_min_usec != UINT64_MAX, "passwordChangeMinUSec", JSON_BUILD_UNSIGNED(hr->password_change_min_usec)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->password_change_max_usec != UINT64_MAX, "passwordChangeMaxUSec", JSON_BUILD_UNSIGNED(hr->password_change_max_usec)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->password_change_warn_usec != UINT64_MAX, "passwordChangeWarnUSec", JSON_BUILD_UNSIGNED(hr->password_change_warn_usec)),
+                                       JSON_BUILD_PAIR_CONDITION(hr->password_change_inactive_usec != UINT64_MAX, "passwordChangeInactiveUSec", JSON_BUILD_UNSIGNED(hr->password_change_inactive_usec))));
+
+        if (r < 0)
+                return r;
+
+        hr->mask = USER_RECORD_REGULAR |
+                (!strv_isempty(hr->hashed_password) ? USER_RECORD_PRIVILEGED : 0);
+
+        *ret = TAKE_PTR(hr);
+        return 0;
+}
+
+int nss_spwd_for_passwd(const struct passwd *pwd, struct spwd *ret_spwd, char **ret_buffer) {
+        size_t buflen = 4096;
+        int r;
+
+        assert(pwd);
+        assert(ret_spwd);
+        assert(ret_buffer);
+
+        for (;;) {
+                _cleanup_free_ char *buf = NULL;
+                struct spwd spwd, *result;
+
+                buf = malloc(buflen);
+                if (!buf)
+                        return -ENOMEM;
+
+                r = getspnam_r(pwd->pw_name, &spwd, buf, buflen, &result);
+                if (r == 0) {
+                        if (!result)
+                                return -ESRCH;
+
+                        *ret_spwd = *result;
+                        *ret_buffer = TAKE_PTR(buf);
+                        return 0;
+                }
+                if (r < 0)
+                        return -EIO; /* Weird, this should not return negative! */
+                if (r != ERANGE)
+                        return -r;
+
+                if (buflen > SIZE_MAX / 2)
+                        return -ERANGE;
+
+                buflen *= 2;
+                buf = mfree(buf);
+        }
+}
+
+int nss_user_record_by_name(const char *name, UserRecord **ret) {
+        _cleanup_free_ char *buf = NULL, *sbuf = NULL;
+        struct passwd pwd, *result;
+        bool incomplete = false;
+        size_t buflen = 4096;
+        struct spwd spwd;
+        int r;
+
+        assert(name);
+        assert(ret);
+
+        for (;;) {
+                buf = malloc(buflen);
+                if (!buf)
+                        return -ENOMEM;
+
+                r = getpwnam_r(name, &pwd, buf, buflen, &result);
+                if (r == 0)  {
+                        if (!result)
+                                return -ESRCH;
+
+                        break;
+                }
+
+                if (r < 0)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EIO), "getpwnam_r() returned a negative value");
+                if (r != ERANGE)
+                        return -r;
+
+                if (buflen > SIZE_MAX / 2)
+                        return -ERANGE;
+
+                buflen *= 2;
+                buf = mfree(buf);
+        }
+
+        r = nss_spwd_for_passwd(result, &spwd, &sbuf);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to do shadow lookup for user %s, ignoring: %m", name);
+                incomplete = ERRNO_IS_PRIVILEGE(r);
+        }
+
+        r = nss_passwd_to_user_record(result, r >= 0 ? &spwd : NULL, ret);
+        if (r < 0)
+                return r;
+
+        (*ret)->incomplete = incomplete;
+        return 0;
+}
+
+int nss_user_record_by_uid(uid_t uid, UserRecord **ret) {
+        _cleanup_free_ char *buf = NULL, *sbuf = NULL;
+        struct passwd pwd, *result;
+        bool incomplete = false;
+        size_t buflen = 4096;
+        struct spwd spwd;
+        int r;
+
+        assert(ret);
+
+        for (;;) {
+                buf = malloc(buflen);
+                if (!buf)
+                        return -ENOMEM;
+
+                r = getpwuid_r(uid, &pwd, buf, buflen, &result);
+                if (r == 0)  {
+                        if (!result)
+                                return -ESRCH;
+
+                        break;
+                }
+                if (r < 0)
+                        return log_debug_errno(SYNTHETIC_ERRNO(EIO), "getpwuid_r() returned a negative value");
+                if (r != ERANGE)
+                        return -r;
+
+                if (buflen > SIZE_MAX / 2)
+                        return -ERANGE;
+
+                buflen *= 2;
+                buf = mfree(buf);
+        }
+
+        r = nss_spwd_for_passwd(result, &spwd, &sbuf);
+        if (r < 0) {
+                log_debug_errno(r, "Failed to do shadow lookup for UID " UID_FMT ", ignoring: %m", uid);
+                incomplete = ERRNO_IS_PRIVILEGE(r);
+        }
+
+        r = nss_passwd_to_user_record(result, r >= 0 ? &spwd : NULL, ret);
+        if (r < 0)
+                return r;
+
+        (*ret)->incomplete = incomplete;
+        return 0;
+}
diff --git a/src/shared/user-record-nss.h b/src/shared/user-record-nss.h
new file mode 100644
index 0000000000..d5fb23ad2a
--- /dev/null
+++ b/src/shared/user-record-nss.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+#pragma once
+
+#include <pwd.h>
+#include <shadow.h>
+
+#include "user-record.h"
+
+/* Synthesizes a UserRecord object from NSS data */
+
+int nss_passwd_to_user_record(const struct passwd *pwd, const struct spwd *spwd, UserRecord **ret);
+int nss_spwd_for_passwd(const struct passwd *pwd, struct spwd *ret_spwd, char **ret_buffer);
+
+int nss_user_record_by_name(const char *name, UserRecord **ret);
+int nss_user_record_by_uid(uid_t uid, UserRecord **ret);