Add a helper function to set capabilities

Signed-off-by: James Lee <james@codeconstruct.com.au>

Author: SafetyInObscurity

src/mctpd.c

@@ -1444,13 +1444,12 @@ static int listen_control_msg(struct ctx *ctx, uint32_t net)
 {
 	struct sockaddr_mctp addr = { 0 };
 	int rc, sd = -1, val;
-	char *failed;
-	cap_t cap;
 
 	sd = mctp_ops.mctp.socket();
 	if (sd < 0) {
-		failed = "socket()";
-		goto warn_out;
+		rc = -errno;
+		warn("%s: socket() failed", __func__);
+		goto out;
 	}
 
 	addr.smctp_family = AF_MCTP;
@@ -1461,26 +1460,9 @@ static int listen_control_msg(struct ctx *ctx, uint32_t net)
 
 	rc = mctp_ops.mctp.bind(sd, (struct sockaddr *)&addr, sizeof(addr));
 	if (rc < 0) {
-		failed = "bind()";
-		goto warn_out;
-	}
-
-	cap = cap_from_text("CAP_NET_ADMIN=pe");
-	if (!cap) {
-		failed = "cap_from_text()";
-		goto warn_out;
-	}
-
-	rc = cap_set_proc(cap);
-	if (rc < 0) {
-		failed = "cap_set_proc()";
-		goto cap_out;
-	}
-
-	cap_free(cap);
-	if (rc < 0) {
-		failed = "cap_free()";
-		goto warn_out;
+		rc = -errno;
+		warn("%s: bind() failed", __func__);
+		goto out;
 	}
 
 	val = 1;
@@ -1496,15 +1478,6 @@ static int listen_control_msg(struct ctx *ctx, uint32_t net)
 			     cb_listen_control_msg, ctx);
 	return rc;
 
-cap_out:
-	rc = -errno;
-	warn("%s: %s failed", __func__, failed);
-	cap_free(cap);
-	goto out;
-
-warn_out:
-	rc = -errno;
-	warn("%s: %s failed", __func__, failed);
 out:
 	if (rc < 0) {
 		close(sd);
@@ -6371,10 +6344,38 @@ static int endpoint_allocate_eids(struct peer *peer)
 	return 0;
 }
 
+int set_cap(char *str)
+{
+	cap_t cap = cap_from_text(str);
+	int rc;
+
+	if (!cap) {
+		rc = -errno;
+		warnx("Failed allocating capability state: %s, %s %d", str,
+		      strerror(-rc), rc);
+		return rc;
+	}
+
+	rc = cap_set_proc(cap);
+	if (rc < 0) {
+		rc = -errno;
+		warnx("Could not set capabilites: %s, %s %d", str,
+		      strerror(-rc), rc);
+		return rc;
+	}
+
+	rc = cap_free(cap);
+	if (rc < 0) {
+		rc = -errno;
+		warnx("Failed freeing capability state");
+		return errno;
+	}
+	return 0;
+}
+
 int main(int argc, char **argv)
 {
 	struct ctx ctxi = { 0 }, *ctx = &ctxi;
-	cap_t cap;
 	int rc;
 
 	setlinebuf(stdout);
@@ -6394,25 +6395,9 @@ int main(int argc, char **argv)
 		err(EXIT_FAILURE, "Can't read configuration");
 	}
 
-	cap = cap_from_text("CAP_NET_BIND_SERVICE=pe CAP_NET_ADMIN=p");
-	if (!cap) {
-		warnx("Failed allocating capability state, %s %d",
-		      strerror(errno), -errno);
-		return 1;
-	}
-
-	rc = cap_set_proc(cap);
-	if (rc < 0) {
-		warnx("Could not set capabilites %s %d", strerror(errno),
-		      -errno);
-		return 1;
-	}
-
-	rc = cap_free(cap);
-	if (rc < 0) {
-		warnx("Failed freeing capability state");
+	rc = set_cap("CAP_NET_BIND_SERVICE=p CAP_NET_ADMIN=p");
+	if (rc < 0)
 		return 1;
-	}
 
 	ctx->nl = mctp_nl_new(false);
 	if (!ctx->nl) {
@@ -6440,13 +6425,21 @@ int main(int argc, char **argv)
 	if (rc < 0)
 		return 1;
 
+	rc = set_cap("CAP_NET_BIND_SERVICE=pe CAP_NET_ADMIN=p");
+	if (rc < 0)
+		return 1;
+
 	// TODO add net argument?
 	rc = listen_control_msg(ctx, MCTP_NET_ANY);
 	if (rc < 0) {
 		warnx("Error in listen, returned %s %d", strerror(-rc), rc);
 		return 1;
 	}
 
+	rc = set_cap("CAP_NET_ADMIN=pe");
+	if (rc < 0)
+		return 1;
+
 	// All setup must be complete by here, we might immediately
 	// get requests from waiting clients.
 	rc = request_dbus(ctx);