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qemu-char.c: Fix memory leaks in qemu_chr_open_pty when openpty fails

PATCH New Thomas Bächler 1 participant 2 messages Apr 15, 2010 KVM

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Thomas Bächler

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#0 lore raw

PATCH 1/2 qemu-char.c: Fix memory leaks in qemu_chr_open_pty when openpty fails

---
 qemu-char.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
qemu-char.c +2 -0
index 05df971..d845572 100644
@@ -986,6 +986,8 @@ static CharDriverState *qemu_chr_open_pty(QemuOpts *opts)
     s = qemu_mallocz(sizeof(PtyCharDriver));
 
     if (openpty(&s->fd, &slave_fd, pty_name, NULL, NULL) < 0) {
+        qemu_free(chr);
+        qemu_free(s);
         return NULL;
     }
Signature · 1 line
1.7.0.5
author
#1 lore raw

PATCH 2/2 Add a 'screen' backend to qemu-char.c

This backend uses the 'pty' backend, but attaches the pseudo tty to a screen. A user can use 'screen:name' as a char device in a qemu options and run 'screen -R name' to attach to it.

This is very useful for running headless qemu/qemu-kvm machines, where you can create screen sessions for the qemu monitor and serial console.

---
 qemu-char.c   |   33 +++++++++++++++++++++++++++++++--
 qemu-config.c |    3 +++
 2 files changed, 34 insertions(+), 2 deletions(-)
qemu-char.c +31 -2
index d845572..d82e4c6 100644
@@ -973,7 +973,9 @@ static CharDriverState *qemu_chr_open_pty(QemuOpts *opts)
     CharDriverState *chr;
     PtyCharDriver *s;
     struct termios tty;
-    int slave_fd, len;
+    int slave_fd, len, r;
+    const char *screensession;
+    char *cmd;
 #if defined(__OpenBSD__) || defined(__DragonFly__)
     char pty_name[PATH_MAX];
 #define q_ptsname(x) pty_name

@@ -1001,7 +1003,29 @@ static CharDriverState *qemu_chr_open_pty(QemuOpts *opts)
     chr->filename = qemu_malloc(len);
     snprintf(chr->filename, len, "pty:%s", q_ptsname(s->fd));
     qemu_opt_set(opts, "path", q_ptsname(s->fd));
-    fprintf(stderr, "char device redirected to %s\n", q_ptsname(s->fd));
+
+    if((screensession = qemu_opt_get(opts, "screen")) != NULL) {
+        if(strlen(screensession) == 0) {
+            qemu_free(chr);
+            qemu_free(s);
+            return NULL;
+        }
+        len = strlen(screensession) + strlen(q_ptsname(s->fd)) + 20;
+        cmd = qemu_malloc(len);
+        snprintf(cmd, len, "screen -S '%s' -dm '%s'", screensession, q_ptsname(s->fd));
+        r = system(cmd);
+        qemu_free(cmd);
+        if(r == -1 || WEXITSTATUS(r) != 0) {
+            fprintf(stderr, "failed to launch screen\n");
+            qemu_free(chr);
+            qemu_free(s);
+            return NULL;
+        } else {
+            fprintf(stderr, "char device attached to screen session %s\n", screensession);
+        }
+    } else {
+        fprintf(stderr, "char device redirected to %s\n", q_ptsname(s->fd));
+    }
 
     chr->opaque = s;
     chr->chr_write = pty_chr_write;

@@ -2343,6 +2367,11 @@ QemuOpts *qemu_chr_parse_compat(const char *label, const char *filename)
         qemu_opt_set(opts, "path", p);
         return opts;
     }
+    if (strstart(filename, "screen:", &p)) {
+        qemu_opt_set(opts, "backend", "pty");
+        qemu_opt_set(opts, "screen", p);
+        return opts;
+    }
     if (strstart(filename, "tcp:", &p) ||
         strstart(filename, "telnet:", &p)) {
         if (sscanf(p, "%64[^:]:%32[^,]%n", host, port, &pos) < 2) {
qemu-config.c +3 -0
index 150157c..8ebf219 100644
@@ -146,6 +146,9 @@ QemuOptsList qemu_chardev_opts = {
         },{
             .name = "signal",
             .type = QEMU_OPT_BOOL,
+        },{
+            .name = "screen",
+            .type = QEMU_OPT_STRING,
         },
         { /* end if list */ }
     },
Signature · 1 line
1.7.0.5