bootctl: rework to use common verbs parsing, and add searching of ESP path

This rearranges bootctl a bit, so that it uses the usual verbs parsing
routines, and automatically searches the ESP in /boot, /efi or /boot/efi, thus
increasing compatibility with mainstream distros that insist on /boot/efi.

This also adds minimal support for running bootctl in a container environment:
when run inside a container verification of the ESP via raw block device
access, trusting the container manager to mount the ESP correctly. Moreover,
EFI variables are not accessed when running in the container.

2 files changed, 224 insertions, 124 deletions

diff --git a/man/bootctl.xml b/man/bootctl.xml
index 6e835c037f..82c162ee70 100644
--- a/man/bootctl.xml
+++ b/man/bootctl.xml
@@ -101,8 +101,10 @@
       <xi:include href="standard-options.xml" xpointer="help" />
       <xi:include href="standard-options.xml" xpointer="version" />
       <varlistentry>
-        <term><option>--path</option></term>
-        <listitem><para>Path to the EFI system partition. The default is /boot.</para></listitem>
+        <term><option>--path=</option></term>
+        <listitem><para>Path to the EFI System Partition (ESP). If not specified, <filename>/efi</filename>,
+        <filename>/boot</filename>, and <filename>/boot/efi</filename> are checked in turn.  It is recommended to mount
+        the ESP to <filename>/boot</filename>, if possible.</para></listitem>
       </varlistentry>
 
       <varlistentry>
diff --git a/src/boot/bootctl.c b/src/boot/bootctl.c
index f337eb6675..8b2407f145 100644
--- a/src/boot/bootctl.c
+++ b/src/boot/bootctl.c
@@ -42,25 +42,52 @@
 #include "fd-util.h"
 #include "fileio.h"
 #include "locale-util.h"
+#include "parse-util.h"
 #include "rm-rf.h"
 #include "string-util.h"
+#include "strv.h"
+#include "umask-util.h"
 #include "util.h"
+#include "verbs.h"
+#include "virt.h"
 
-static const char *arg_path = "/boot";
+static char *arg_path = NULL;
 static bool arg_touch_variables = true;
 
-static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t *psize, sd_id128_t *uuid) {
-        struct statfs sfs;
-        struct stat st, st2;
-        _cleanup_free_ char *t = NULL;
+static int verify_esp(
+                bool searching,
+                const char *p,
+                uint32_t *ret_part,
+                uint64_t *ret_pstart,
+                uint64_t *ret_psize,
+                sd_id128_t *ret_uuid) {
+
         _cleanup_blkid_free_probe_ blkid_probe b = NULL;
-        int r;
+        _cleanup_free_ char *t = NULL;
+        uint64_t pstart = 0, psize = 0;
+        struct stat st, st2;
         const char *v, *t2;
+        struct statfs sfs;
+        sd_id128_t uuid = SD_ID128_NULL;
+        uint32_t part = 0;
+        int r;
+
+        assert(p);
+
+        if (statfs(p, &sfs) < 0) {
+
+                /* If we are searching for the mount point, don't generate a log message if we can't find the path */
+                if (errno == ENOENT && searching)
+                        return -ENOENT;
 
-        if (statfs(p, &sfs) < 0)
                 return log_error_errno(errno, "Failed to check file system type of \"%s\": %m", p);
+        }
 
         if (sfs.f_type != 0x4d44) {
+
+                if (searching)
+                        return -EADDRNOTAVAIL;
+
                 log_error("File system \"%s\" is not a FAT EFI System Partition (ESP) file system.", p);
                 return -ENODEV;
         }
@@ -83,6 +110,11 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 return -ENODEV;
         }
 
+        /* In a container we don't have access to block devices, skip this part of the verification, we trust the
+         * container manager set everything up correctly on its own. */
+        if (detect_container() > 0)
+                goto finish;
+
         r = asprintf(&t, "/dev/block/%u:%u", major(st.st_dev), minor(st.st_dev));
         if (r < 0)
                 return log_oom();
@@ -120,7 +152,6 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe file system type \"%s\": %m", p);
         }
-
         if (!streq(v, "vfat")) {
                 log_error("File system \"%s\" is not FAT.", p);
                 return -ENODEV;
@@ -132,7 +163,6 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe partition scheme \"%s\": %m", p);
         }
-
         if (!streq(v, "gpt")) {
                 log_error("File system \"%s\" is not on a GPT partition table.", p);
                 return -ENODEV;
@@ -144,7 +174,6 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe partition type UUID \"%s\": %m", p);
         }
-
         if (!streq(v, "c12a7328-f81f-11d2-ba4b-00a0c93ec93b")) {
                 log_error("File system \"%s\" has wrong type for an EFI System Partition (ESP).", p);
                 return -ENODEV;
@@ -156,8 +185,7 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe partition entry UUID \"%s\": %m", p);
         }
-
-        r = sd_id128_from_string(v, uuid);
+        r = sd_id128_from_string(v, &uuid);
         if (r < 0) {
                 log_error("Partition \"%s\" has invalid UUID \"%s\".", p, v);
                 return -EIO;
@@ -169,7 +197,9 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe partition number \"%s\": m", p);
         }
-        *part = strtoul(v, NULL, 10);
+        r = safe_atou32(v, &part);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse PART_ENTRY_NUMBER field.");
 
         errno = 0;
         r = blkid_probe_lookup_value(b, "PART_ENTRY_OFFSET", &v, NULL);
@@ -177,7 +207,9 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe partition offset \"%s\": %m", p);
         }
-        *pstart = strtoul(v, NULL, 10);
+        r = safe_atou64(v, &pstart);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse PART_ENTRY_OFFSET field.");
 
         errno = 0;
         r = blkid_probe_lookup_value(b, "PART_ENTRY_SIZE", &v, NULL);
@@ -185,11 +217,50 @@ static int verify_esp(const char *p, uint32_t *part, uint64_t *pstart, uint64_t
                 r = errno ? -errno : -EIO;
                 return log_error_errno(r, "Failed to probe partition size \"%s\": %m", p);
         }
-        *psize = strtoul(v, NULL, 10);
+        r = safe_atou64(v, &psize);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse PART_ENTRY_SIZE field.");
+
+finish:
+        if (ret_part)
+                *ret_part = part;
+        if (ret_pstart)
+                *ret_pstart = pstart;
+        if (ret_psize)
+                *ret_psize = psize;
+        if (ret_uuid)
+                *ret_uuid = uuid;
 
         return 0;
 }
 
+static int find_esp(uint32_t *part, uint64_t *pstart, uint64_t *psize, sd_id128_t *uuid) {
+        const char *path;
+        int r;
+
+        if (arg_path)
+                return verify_esp(false, arg_path, part, pstart, psize, uuid);
+
+        FOREACH_STRING(path, "/efi", "/boot", "/boot/efi") {
+
+                r = verify_esp(true, path, part, pstart, psize, uuid);
+                if (IN_SET(r, -ENOENT, -EADDRNOTAVAIL)) /* This one is not it */
+                        continue;
+                if (r < 0)
+                        return r;
+
+                arg_path = strdup(path);
+                if (!arg_path)
+                        return log_oom();
+
+                log_info("Using EFI System Parition at %s.", path);
+                return 0;
+        }
+
+        log_error("Couldn't find EFI system partition. It is recommended to mount it to /boot. Alternatively, use --path= to specify path to mount point.");
+        return -ENOENT;
+}
+
 /* search for "#### LoaderInfo: systemd-boot 218 ####" string inside the binary */
 static int get_file_version(int fd, char **v) {
         struct stat st;
@@ -914,7 +985,8 @@ static int install_loader_config(const char *esp_path) {
         return 0;
 }
 
-static int help(void) {
+static int help(int argc, char *argv[], void *userdata) {
+
         printf("%s [COMMAND] [OPTIONS...]\n"
                "\n"
                "Install, update or remove the systemd-boot EFI boot manager.\n\n"
@@ -948,7 +1020,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { NULL,           0,                 NULL, 0                }
         };
 
-        int c;
+        int c, r;
 
         assert(argc >= 0);
         assert(argv);
@@ -957,14 +1029,16 @@ static int parse_argv(int argc, char *argv[]) {
                 switch (c) {
 
                 case 'h':
-                        help();
+                        help(0, NULL, NULL);
                         return 0;
 
                 case ARG_VERSION:
                         return version();
 
                 case ARG_PATH:
-                        arg_path = optarg;
+                        r = free_and_strdup(&arg_path, optarg);
+                        if (r < 0)
+                                return log_oom();
                         break;
 
                 case ARG_NO_VARIABLES:
@@ -989,147 +1063,170 @@ static void read_loader_efi_var(const char *name, char **var) {
                 log_warning_errno(r, "Failed to read EFI variable %s: %m", name);
 }
 
-static int bootctl_main(int argc, char*argv[]) {
-        enum action {
-                ACTION_STATUS,
-                ACTION_INSTALL,
-                ACTION_UPDATE,
-                ACTION_REMOVE
-        } arg_action = ACTION_STATUS;
-        static const struct {
-                const char* verb;
-                enum action action;
-        } verbs[] = {
-                { "status",  ACTION_STATUS },
-                { "install", ACTION_INSTALL },
-                { "update",  ACTION_UPDATE },
-                { "remove",  ACTION_REMOVE },
-        };
+static int must_be_root(void) {
 
-        sd_id128_t uuid = {};
-        uint32_t part = 0;
-        uint64_t pstart = 0, psize = 0;
-        int r, q;
+        if (geteuid() == 0)
+                return 0;
 
-        if (argv[optind]) {
-                unsigned i;
+        log_error("Need to be root.");
+        return -EPERM;
+}
 
-                for (i = 0; i < ELEMENTSOF(verbs); i++) {
-                        if (!streq(argv[optind], verbs[i].verb))
-                                continue;
-                        arg_action = verbs[i].action;
-                        break;
-                }
-                if (i >= ELEMENTSOF(verbs)) {
-                        log_error("Unknown operation \"%s\"", argv[optind]);
-                        return -EINVAL;
-                }
-        }
+static int verb_status(int argc, char *argv[], void *userdata) {
 
-        if (geteuid() != 0)
-                return log_error_errno(EPERM, "Need to be root.");
+        sd_id128_t uuid = SD_ID128_NULL;
+        int r;
 
-        r = verify_esp(arg_path, &part, &pstart, &psize, &uuid);
-        if (r == -ENODEV && !arg_path)
-                log_notice("You might want to use --path= to indicate the path to your ESP, in case it is not mounted on /boot.");
+        r = must_be_root();
         if (r < 0)
                 return r;
 
-        switch (arg_action) {
+        r = find_esp(NULL, NULL, NULL, &uuid);
+        if (r < 0)
+                return r;
 
-        case ACTION_STATUS: {
+        if (is_efi_boot()) {
                 _cleanup_free_ char *fw_type = NULL, *fw_info = NULL, *loader = NULL, *loader_path = NULL;
                 sd_id128_t loader_part_uuid = SD_ID128_NULL;
 
-                if (is_efi_boot()) {
-                        read_loader_efi_var("LoaderFirmwareType", &fw_type);
-                        read_loader_efi_var("LoaderFirmwareInfo", &fw_info);
-                        read_loader_efi_var("LoaderInfo", &loader);
-                        read_loader_efi_var("LoaderImageIdentifier", &loader_path);
-                        if (loader_path)
-                                efi_tilt_backslashes(loader_path);
-                        r = efi_loader_get_device_part_uuid(&loader_part_uuid);
-                        if (r < 0 && r != -ENOENT)
-                                log_warning_errno(r, "Failed to read EFI variable LoaderDevicePartUUID: %m");
-
-                        printf("System:\n");
-                        printf("     Firmware: %s (%s)\n", strna(fw_type), strna(fw_info));
-
-                        r = is_efi_secure_boot();
-                        if (r < 0)
-                                log_warning_errno(r, "Failed to query secure boot status: %m");
-                        else
-                                printf("  Secure Boot: %s\n", r ? "enabled" : "disabled");
+                read_loader_efi_var("LoaderFirmwareType", &fw_type);
+                read_loader_efi_var("LoaderFirmwareInfo", &fw_info);
+                read_loader_efi_var("LoaderInfo", &loader);
+                read_loader_efi_var("LoaderImageIdentifier", &loader_path);
 
-                        r = is_efi_secure_boot_setup_mode();
-                        if (r < 0)
-                                log_warning_errno(r, "Failed to query secure boot mode: %m");
-                        else
-                                printf("   Setup Mode: %s\n", r ? "setup" : "user");
-                        printf("\n");
-
-                        printf("Loader:\n");
-                        printf("      Product: %s\n", strna(loader));
-                        if (!sd_id128_equal(loader_part_uuid, SD_ID128_NULL))
-                                printf("    Partition: /dev/disk/by-partuuid/%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
-                                       SD_ID128_FORMAT_VAL(loader_part_uuid));
-                        else
-                                printf("    Partition: n/a\n");
-                        printf("         File: %s%s\n", special_glyph(TREE_RIGHT), strna(loader_path));
-                        printf("\n");
-                } else
-                        printf("System:\n    Not booted with EFI\n");
-
-                r = status_binaries(arg_path, uuid);
+                if (loader_path)
+                        efi_tilt_backslashes(loader_path);
+
+                r = efi_loader_get_device_part_uuid(&loader_part_uuid);
+                if (r < 0 && r != -ENOENT)
+                        log_warning_errno(r, "Failed to read EFI variable LoaderDevicePartUUID: %m");
+
+                printf("System:\n");
+                printf("     Firmware: %s (%s)\n", strna(fw_type), strna(fw_info));
+
+                r = is_efi_secure_boot();
                 if (r < 0)
-                        return r;
+                        log_warning_errno(r, "Failed to query secure boot status: %m");
+                else
+                        printf("  Secure Boot: %s\n", r ? "enabled" : "disabled");
 
-                if (arg_touch_variables)
-                        r = status_variables();
-                break;
-        }
+                r = is_efi_secure_boot_setup_mode();
+                if (r < 0)
+                        log_warning_errno(r, "Failed to query secure boot mode: %m");
+                else
+                        printf("   Setup Mode: %s\n", r ? "setup" : "user");
+                printf("\n");
+
+                printf("Loader:\n");
+                printf("      Product: %s\n", strna(loader));
+                if (!sd_id128_equal(loader_part_uuid, SD_ID128_NULL))
+                        printf("    Partition: /dev/disk/by-partuuid/%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x\n",
+                               SD_ID128_FORMAT_VAL(loader_part_uuid));
+                else
+                        printf("    Partition: n/a\n");
+                printf("         File: %s%s\n", special_glyph(TREE_RIGHT), strna(loader_path));
+                printf("\n");
+        } else
+                printf("System:\n    Not booted with EFI\n");
+
+        r = status_binaries(arg_path, uuid);
+        if (r < 0)
+                return r;
+
+        if (arg_touch_variables)
+                r = status_variables();
+
+        return r;
+}
 
-        case ACTION_INSTALL:
-        case ACTION_UPDATE:
-                umask(0002);
+static int verb_install(int argc, char *argv[], void *userdata) {
 
-                r = install_binaries(arg_path, arg_action == ACTION_INSTALL);
+        sd_id128_t uuid = SD_ID128_NULL;
+        uint64_t pstart = 0, psize = 0;
+        uint32_t part = 0;
+        bool install;
+        int r;
+
+        r = must_be_root();
+        if (r < 0)
+                return r;
+
+        r = find_esp(&part, &pstart, &psize, &uuid);
+        if (r < 0)
+                return r;
+
+        install = streq(argv[0], "install");
+
+        RUN_WITH_UMASK(0002) {
+                r = install_binaries(arg_path, install);
                 if (r < 0)
                         return r;
 
-                if (arg_action == ACTION_INSTALL) {
+                if (install) {
                         r = install_loader_config(arg_path);
                         if (r < 0)
                                 return r;
                 }
+        }
+
+        if (arg_touch_variables)
+                r = install_variables(arg_path,
+                                      part, pstart, psize, uuid,
+                                      "/EFI/systemd/systemd-boot" EFI_MACHINE_TYPE_NAME ".efi",
+                                      install);
 
-                if (arg_touch_variables)
-                        r = install_variables(arg_path,
-                                              part, pstart, psize, uuid,
-                                              "/EFI/systemd/systemd-boot" EFI_MACHINE_TYPE_NAME ".efi",
-                                              arg_action == ACTION_INSTALL);
-                break;
+        return r;
+}
 
-        case ACTION_REMOVE:
-                r = remove_binaries(arg_path);
+static int verb_remove(int argc, char *argv[], void *userdata) {
+        sd_id128_t uuid = SD_ID128_NULL;
+        int r;
 
-                if (arg_touch_variables) {
-                        q = remove_variables(uuid, "/EFI/systemd/systemd-boot" EFI_MACHINE_TYPE_NAME ".efi", true);
-                        if (q < 0 && r == 0)
-                                r = q;
-                }
-                break;
+        r = must_be_root();
+        if (r < 0)
+                return r;
+
+        r = find_esp(NULL, NULL, NULL, &uuid);
+        if (r < 0)
+                return r;
+
+        r = remove_binaries(arg_path);
+
+        if (arg_touch_variables) {
+                int q;
+
+                q = remove_variables(uuid, "/EFI/systemd/systemd-boot" EFI_MACHINE_TYPE_NAME ".efi", true);
+                if (q < 0 && r == 0)
+                        r = q;
         }
 
         return r;
 }
 
+static int bootctl_main(int argc, char *argv[]) {
+
+        static const Verb verbs[] = {
+                { "help",            VERB_ANY, VERB_ANY, 0,            help         },
+                { "status",          VERB_ANY, 1,        VERB_DEFAULT, verb_status  },
+                { "install",         VERB_ANY, 1,        0,            verb_install },
+                { "update",          VERB_ANY, 1,        0,            verb_install },
+                { "remove",          VERB_ANY, 1,        0,            verb_remove  },
+                {}
+        };
+
+        return dispatch_verb(argc, argv, verbs, NULL);
+}
+
 int main(int argc, char *argv[]) {
         int r;
 
         log_parse_environment();
         log_open();
 
+        /* If we run in a container, automatically turn of EFI file system access */
+        if (detect_container() > 0)
+                arg_touch_variables = false;
+
         r = parse_argv(argc, argv);
         if (r <= 0)
                 goto finish;
@@ -1137,5 +1234,6 @@ int main(int argc, char *argv[]) {
         r = bootctl_main(argc, argv);
 
  finish:
+        free(arg_path);
         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 }