Add functions for saving fd's and ram extents in the environment via
setenv, and for reading them back via getenv.
Signed-off-by: Steve Sistare <steven.sist...@oracle.com>
Signed-off-by: Mark Kanda <mark.ka...@oracle.com>
---
MAINTAINERS | 7 +++
include/qemu/cutils.h | 1 +
include/qemu/env.h | 31 ++++++++++++
util/Makefile.objs | 2 +-
util/env.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 172 insertions(+), 1 deletion(-)
create mode 100644 include/qemu/env.h
create mode 100644 util/env.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 3395abd..8d377a7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3115,3 +3115,10 @@ Performance Tools and Tests
M: Ahmed Karaman <ahmedkhaledkara...@gmail.com>
S: Maintained
F: scripts/performance/
+
+Environment variable helpers
+M: Steve Sistare <steven.sist...@oracle.com>
+M: Mark Kanda <mark.ka...@oracle.com>
+S: Maintained
+F: include/qemu/env.h
+F: util/env.c
diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
index eb59852..d4c7d70 100644
--- a/include/qemu/cutils.h
+++ b/include/qemu/cutils.h
@@ -1,6 +1,7 @@
#ifndef QEMU_CUTILS_H
#define QEMU_CUTILS_H
+#include "qemu/env.h"
/**
* pstrcpy:
* @buf: buffer to copy string into
diff --git a/include/qemu/env.h b/include/qemu/env.h
new file mode 100644
index 0000000..53cc121
--- /dev/null
+++ b/include/qemu/env.h
@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#ifndef QEMU_ENV_H
+#define QEMU_ENV_H
+
+#define FD_PREFIX "QEMU_FD_"
+#define ADDR_PREFIX "QEMU_ADDR_"
+#define LEN_PREFIX "QEMU_LEN_"
+#define BOOL_PREFIX "QEMU_BOOL_"
+
+typedef int (*walkenv_cb)(const char *name, const char *val, void *handle);
+
+bool getenv_ram(const char *name, void **addrp, size_t *lenp);
+void setenv_ram(const char *name, void *addr, size_t len);
+void unsetenv_ram(const char *name);
+int getenv_fd(const char *name);
+void setenv_fd(const char *name, int fd);
+void unsetenv_fd(const char *name);
+bool getenv_bool(const char *name);
+void setenv_bool(const char *name, bool val);
+void unsetenv_bool(const char *name);
+int walkenv(const char *prefix, walkenv_cb cb, void *handle);
+void printenv(void);
+
+#endif
diff --git a/util/Makefile.objs b/util/Makefile.objs
index cc5e371..d357932 100644
--- a/util/Makefile.objs
+++ b/util/Makefile.objs
@@ -1,4 +1,4 @@
-util-obj-y = osdep.o cutils.o unicode.o qemu-timer-common.o
+util-obj-y = osdep.o cutils.o unicode.o qemu-timer-common.o env.o
util-obj-$(call lnot,$(CONFIG_ATOMIC64)) += atomic64.o
util-obj-$(CONFIG_POSIX) += aio-posix.o
util-obj-$(CONFIG_POSIX) += fdmon-poll.o
diff --git a/util/env.c b/util/env.c
new file mode 100644
index 0000000..0cc4a9f
--- /dev/null
+++ b/util/env.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 2020 Oracle and/or its affiliates.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/env.h"
+
+static uint64_t getenv_ulong(const char *prefix, const char *name, bool *found)
+{
+ char var[80], *val;
+ uint64_t res;
+
+ snprintf(var, sizeof(var), "%s%s", prefix, name);
+ val = getenv(var);
+ if (val) {
+ *found = true;
+ res = strtol(val, 0, 10);
+ } else {
+ *found = false;
+ res = 0;
+ }
+ return res;
+}
+
+static void setenv_ulong(const char *prefix, const char *name, uint64_t val)
+{
+ char var[80], val_str[80];
+ snprintf(var, sizeof(var), "%s%s", prefix, name);
+ snprintf(val_str, sizeof(val_str), "%"PRIu64, val);
+ setenv(var, val_str, 1);
+}
+
+static void unsetenv_ulong(const char *prefix, const char *name)
+{
+ char var[80];
+ snprintf(var, sizeof(var), "%s%s", prefix, name);
+ unsetenv(var);
+}
+
+bool getenv_ram(const char *name, void **addrp, size_t *lenp)
+{
+ bool found1, found2;
+ *addrp = (void *) getenv_ulong(ADDR_PREFIX, name, &found1);
+ *lenp = getenv_ulong(LEN_PREFIX, name, &found2);
+ assert(found1 == found2);
+ return found1;
+}
+
+void setenv_ram(const char *name, void *addr, size_t len)
+{
+ setenv_ulong(ADDR_PREFIX, name, (uint64_t)addr);
+ setenv_ulong(LEN_PREFIX, name, len);
+}
+
+void unsetenv_ram(const char *name)
+{
+ unsetenv_ulong(ADDR_PREFIX, name);
+ unsetenv_ulong(LEN_PREFIX, name);
+}
+
+int getenv_fd(const char *name)
+{
+ bool found;
+ int fd = getenv_ulong(FD_PREFIX, name, &found);
+ if (!found) {
+ fd = -1;
+ }
+ return fd;
+}
+
+void setenv_fd(const char *name, int fd)
+{
+ setenv_ulong(FD_PREFIX, name, fd);
+}
+
+void unsetenv_fd(const char *name)
+{
+ unsetenv_ulong(FD_PREFIX, name);
+}
+
+bool getenv_bool(const char *name)
+{
+ bool found;
+ bool val = getenv_ulong(BOOL_PREFIX, name, &found);
+ if (!found) {
+ val = -1;
+ }
+ return val;
+}
+
+void setenv_bool(const char *name, bool val)
+{
+ setenv_ulong(BOOL_PREFIX, name, val);
+}
+
+void unsetenv_bool(const char *name)
+{
+ unsetenv_ulong(BOOL_PREFIX, name);
+}
+
+int walkenv(const char *prefix, walkenv_cb cb, void *handle)
+{
+ char *str, name[128];
+ char **envp = environ;
+ size_t prefix_len = strlen(prefix);
+
+ while (*envp) {
+ str = *envp++;
+ if (!strncmp(str, prefix, prefix_len)) {
+ char *val = strchr(str, '=');
+ str += prefix_len;
+ strncpy(name, str, val - str);
+ name[val - str] = 0;
+ if (cb(name, val + 1, handle)) {
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+void printenv(void)
+{
+ char **ptr = environ;
+ while (*ptr) {
+ puts(*ptr++);
+ }
+}
--
1.8.3.1
