From 54806234834ab5f2a1ada02afc5ad5ef6a789dc9 Mon Sep 17 00:00:00 2001

Message-Id: <54806234834ab5f2a1ada02afc5ad5ef6a789dc9@dist-git>

From: Laine Stump <laine@redhat.com>

Date: Wed, 1 Mar 2023 11:34:24 -0500

Subject: [PATCH] util: add an API to retrieve the resolved path to a

 virCommand's binary

The binary to be exec'ed by virExec() is stored in

virCommand::args[0], and is resolved to a full absolute path (stored

in a local of virExec() just prior to execve().

Since we will have another use for the full absolute path, lets make

an API to resolve/retrieve the absolute path, and cache it in

virCommand::binaryPath so we only have to do the resolution once.

Signed-off-by: Laine Stump <laine@redhat.com>

Reviewed-by: Andrea Bolognani <abologna@redhat.com>

Reviewed-by: Michal Privoznik <mprivozn@redhat.com>

(cherry picked from commit a53c1d6f842ba0f516bbacff8250ba0d7a10074a)

https://bugzilla.redhat.com/2172267

Signed-off-by: Laine Stump <laine@redhat.com>

---

 src/libvirt_private.syms |  1 +

 src/util/vircommand.c    | 51 +++++++++++++++++++++++++++++++---------

 src/util/vircommand.h    |  1 +

 3 files changed, 42 insertions(+), 11 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms

index 576ec8f95f..e20421e7cd 100644

--- a/src/libvirt_private.syms

+++ b/src/libvirt_private.syms

@@ -2076,6 +2076,7 @@ virCommandDryRunTokenNew;

 virCommandExec;

 virCommandFree;

 virCommandGetArgList;

+virCommandGetBinaryPath;

 virCommandGetGID;

 virCommandGetUID;

 virCommandHandshakeNotify;

diff --git a/src/util/vircommand.c b/src/util/vircommand.c

index 0917bc9cfb..a31509e977 100644

--- a/src/util/vircommand.c

+++ b/src/util/vircommand.c

@@ -88,6 +88,7 @@ struct _virCommandSendBuffer {

 struct _virCommand {

     int has_error; /* 0 on success, -1 on error  */

+    char *binaryPath; /* only valid if args[0] isn't absolute path */

     char **args;

     size_t nargs;

     size_t maxargs;

@@ -630,6 +631,7 @@ virCommandMassClose(virCommand *cmd,

 # endif /* ! __FreeBSD__ */

+

 /*

  * virExec:

  * @cmd virCommand * containing all information about the program to

@@ -646,22 +648,13 @@ virExec(virCommand *cmd)

     int childin = cmd->infd;

     int childout = -1;

     int childerr = -1;

-    g_autofree char *binarystr = NULL;

     const char *binary = NULL;

     int ret;

     g_autofree gid_t *groups = NULL;

     int ngroups;

-    if (!g_path_is_absolute(cmd->args[0])) {

-        if (!(binary = binarystr = virFindFileInPath(cmd->args[0]))) {

-            virReportSystemError(ENOENT,

-                                 _("Cannot find '%s' in path"),

-                                 cmd->args[0]);

-            return -1;

-        }

-    } else {

-        binary = cmd->args[0];

-    }

+    if (!(binary = virCommandGetBinaryPath(cmd)))

+        return -1;

     if (childin < 0) {

         if (getDevNull(&null) < 0)

@@ -2164,6 +2157,40 @@ virCommandGetArgList(virCommand *cmd,

 }

+/*

+ * virCommandGetBinaryPath:

+ * @cmd: virCommand* containing all information about the program

+ *

+ * If args[0] is an absolute path, return that. If not, then resolve

+ * args[0] to a full absolute path, cache that in binaryPath, and

+ * return a pointer to this resolved string. binaryPath is only set by

+ * calling this function, so even other virCommand functions should

+ * access binaryPath via this function.

+ *

+ * returns const char* with the full path of the binary to be

+ * executed, or NULL on failure.

+ */

+const char *

+virCommandGetBinaryPath(virCommand *cmd)

+{

+

+    if (cmd->binaryPath)

+        return cmd->binaryPath;

+

+    if (g_path_is_absolute(cmd->args[0]))

+        return cmd->args[0];

+

+    if (!(cmd->binaryPath = virFindFileInPath(cmd->args[0]))) {

+        virReportSystemError(ENOENT,

+                             _("Cannot find '%s' in path"),

+                             cmd->args[0]);

+        return NULL;

+    }

+

+    return cmd->binaryPath;

+}

+

+

 #ifndef WIN32

 /*

  * Manage input and output to the child process.

@@ -3015,6 +3042,8 @@ virCommandFree(virCommand *cmd)

     VIR_FORCE_CLOSE(cmd->outfd);

     VIR_FORCE_CLOSE(cmd->errfd);

+    g_free(cmd->binaryPath);

+

     for (i = 0; i < cmd->nargs; i++)

         g_free(cmd->args[i]);

     g_free(cmd->args);

diff --git a/src/util/vircommand.h b/src/util/vircommand.h

index e0002103b6..d51449ac90 100644

--- a/src/util/vircommand.h

+++ b/src/util/vircommand.h

@@ -170,6 +170,7 @@ int virCommandToStringBuf(virCommand *cmd,

                           bool linebreaks,

                           bool stripCommandPath);

+const char *virCommandGetBinaryPath(virCommand *cmd);

 int virCommandGetArgList(virCommand *cmd, char ***args);

 int virCommandExec(virCommand *cmd, gid_t *groups, int ngroups) G_GNUC_WARN_UNUSED_RESULT;

-- 

2.40.0