util: use new VT ESC sequence to clear scrollback buffer

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index b337778d0ef96524447b4a3231588b1371a734b4..a271708ba291979b17e6c4881389ad85b921ad4f 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -2141,7 +2141,7 @@ bool fstype_is_network(const char *fstype) {
 int chvt(int vt) {
         int fd, r = 0;
 
-        if ((fd = open("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0)
+        if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0)
                 return -errno;
 
         if (vt < 0) {
@@ -2261,7 +2261,7 @@ int ask(char *ret, const char *replies, const char *text, ...) {
         }
 }
 
-int reset_terminal(int fd) {
+int reset_terminal_fd(int fd) {
         struct termios termios;
         int r = 0;
         long arg;
@@ -2323,6 +2323,19 @@ finish:
         return r;
 }
 
+int reset_terminal(const char *name) {
+        int fd, r;
+
+        fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return fd;
+
+        r = reset_terminal_fd(fd);
+        close_nointr_nofail(fd);
+
+        return r;
+}
+
 int open_terminal(const char *name, int mode) {
         int fd, r;
         unsigned c = 0;
@@ -2443,8 +2456,8 @@ int acquire_terminal(const char *name, bool fail, bool force, bool ignore_tiocst
                 /* We pass here O_NOCTTY only so that we can check the return
                  * value TIOCSCTTY and have a reliable way to figure out if we
                  * successfully became the controlling process of the tty */
-                if ((fd = open_terminal(name, O_RDWR|O_NOCTTY)) < 0)
-                        return -errno;
+                if ((fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC)) < 0)
+                        return fd;
 
                 /* First, try to get the tty */
                 r = ioctl(fd, TIOCSCTTY, force);
@@ -2511,7 +2524,7 @@ int acquire_terminal(const char *name, bool fail, bool force, bool ignore_tiocst
         if (notify >= 0)
                 close_nointr_nofail(notify);
 
-        if ((r = reset_terminal(fd)) < 0)
+        if ((r = reset_terminal_fd(fd)) < 0)
                 log_warning("Failed to reset terminal: %s", strerror(-r));
 
         return fd;
@@ -4011,7 +4024,7 @@ int detect_vm(const char **id) {
                 : "0" (eax)
         );
 
-        hypervisor = !!(ecx & ecx & 0x80000000U);
+        hypervisor = !!(ecx & 0x80000000U);
 
         if (hypervisor) {
 
@@ -4413,6 +4426,88 @@ char* hostname_cleanup(char *s) {
         return s;
 }
 
+int terminal_vhangup_fd(int fd) {
+        if (ioctl(fd, TIOCVHANGUP) < 0)
+                return -errno;
+
+        return 0;
+}
+
+int terminal_vhangup(const char *name) {
+        int fd, r;
+
+        fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return fd;
+
+        r = terminal_vhangup_fd(fd);
+        close_nointr_nofail(fd);
+
+        return r;
+}
+
+int vt_disallocate(const char *name) {
+        int fd, r;
+        unsigned u;
+
+        /* Deallocate the VT if possible. If not possible
+         * (i.e. because it is the active one), at least clear it
+         * entirely (including the scrollback buffer) */
+
+        if (!startswith(name, "/dev/"))
+                return -EINVAL;
+
+        if (!tty_is_vc(name)) {
+                /* So this is not a VT. I guess we cannot deallocate
+                 * it then. But let's at least clear the screen */
+
+                fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+                if (fd < 0)
+                        return fd;
+
+                loop_write(fd, "\033[H\033[2J", 7, false); /* clear screen */
+                close_nointr_nofail(fd);
+
+                return 0;
+        }
+
+        if (!startswith(name, "/dev/tty"))
+                return -EINVAL;
+
+        r = safe_atou(name+8, &u);
+        if (r < 0)
+                return r;
+
+        if (u <= 0)
+                return -EINVAL;
+
+        /* Try to deallocate */
+        fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return fd;
+
+        r = ioctl(fd, VT_DISALLOCATE, u);
+        close_nointr_nofail(fd);
+
+        if (r >= 0)
+                return 0;
+
+        if (errno != EBUSY)
+                return -errno;
+
+        /* Couldn't deallocate, so let's clear it fully with
+         * scrollback */
+        fd = open_terminal(name, O_RDWR|O_NOCTTY|O_CLOEXEC);
+        if (fd < 0)
+                return fd;
+
+        /* Requires Linux 2.6.40 */
+        loop_write(fd, "\033[H\033[3J", 7, false); /* clear screen including scrollback */
+        close_nointr_nofail(fd);
+
+        return 0;
+}
+
 static const char *const ioprio_class_table[] = {
         [IOPRIO_CLASS_NONE] = "none",
         [IOPRIO_CLASS_RT] = "realtime",
@@ -4576,17 +4671,25 @@ static int files_add(Hashmap *h, const char *path, const char *suffix) {
         }
 
         for (de = readdir(dir); de; de = readdir(dir)) {
-                char *f;
+                char *p, *f;
                 const char *base;
 
                 if (!file_is_conf(de, suffix))
                         continue;
 
-                if (asprintf(&f, "%s/%s", path, de->d_name) < 0) {
+                if (asprintf(&p, "%s/%s", path, de->d_name) < 0) {
                         r = -ENOMEM;
                         goto finish;
                 }
 
+                f = canonicalize_file_name(p);
+                if (!f) {
+                        log_error("Failed to canonicalize file name '%s': %m", p);
+                        free(p);
+                        continue;
+                }
+                free(p);
+
                 log_debug("found: %s\n", f);
                 base = f + strlen(path) + 1;
                 if (hashmap_put(h, base, f) <= 0)
@@ -4607,27 +4710,42 @@ static int base_cmp(const void *a, const void *b) {
 }
 
 int conf_files_list(char ***strv, const char *suffix, const char *dir, ...) {
-        Hashmap *fh;
+        Hashmap *fh = NULL;
+        char **dirs = NULL;
         char **files = NULL;
+        char **p;
         va_list ap;
         int r = 0;
 
+        va_start(ap, dir);
+        dirs = strv_new_ap(dir, ap);
+        va_end(ap);
+        if (!dirs) {
+                r = -ENOMEM;
+                goto finish;
+        }
+        if (!strv_path_canonicalize(dirs)) {
+                r = -ENOMEM;
+                goto finish;
+        }
+        if (!strv_uniq(dirs)) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
         fh = hashmap_new(string_hash_func, string_compare_func);
         if (!fh) {
                 r = -ENOMEM;
                 goto finish;
         }
 
-        va_start(ap, dir);
-        while (dir) {
-                if (files_add(fh, dir, suffix) < 0) {
+        STRV_FOREACH(p, dirs) {
+                if (files_add(fh, *p, suffix) < 0) {
                         log_error("Failed to search for files.");
                         r = -EINVAL;
                         goto finish;
                 }
-                dir = va_arg(ap, const char *);
         }
-        va_end(ap);
 
         files = hashmap_get_strv(fh);
         if (files == NULL) {
@@ -4638,6 +4756,7 @@ int conf_files_list(char ***strv, const char *suffix, const char *dir, ...) {
 
         qsort(files, hashmap_size(fh), sizeof(char *), base_cmp);
 finish:
+        strv_free(dirs);
         hashmap_free(fh);
         *strv = files;
         return r;