From 404fcb1c102af07a6760a80fa994d20e9a4de7f7 Mon Sep 17 00:00:00 2001
From: George Kiagiadakis <george.kiagiadakis@collabora.com>
Date: Fri, 9 Jul 2021 13:35:36 +0300
Subject: lib: avoid static buffers, use alloca() more

Signed-off-by: George Kiagiadakis <george.kiagiadakis@collabora.com>
---
 lib/client.c | 3 ++-
 lib/server.c | 7 ++++---
 lib/utils.c  | 7 +++++--
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/lib/client.c b/lib/client.c
index f1c4da1..d101223 100644
--- a/lib/client.c
+++ b/lib/client.c
@@ -6,6 +6,7 @@
  * SPDX-License-Identifier: MIT
  */
 
+#include <alloca.h>
 #include "private.h"
 #include "protocol.h"
 #include "sender.h"
@@ -50,7 +51,7 @@ bool icipc_client_send_request(
                 return false;
 
         const size_t size = icipc_protocol_calculate_request_size(name, args);
-        uint8_t buffer[size];
+        uint8_t *buffer = alloca(size);
         icipc_protocol_build_request(buffer, size, name, args);
         return icipc_sender_send(base, buffer, size, reply, data);
 }
diff --git a/lib/server.c b/lib/server.c
index 6229ecd..6a67395 100644
--- a/lib/server.c
+++ b/lib/server.c
@@ -8,6 +8,7 @@
 
 #include <pthread.h>
 #include <string.h>
+#include <alloca.h>
 
 #include "private.h"
 #include "protocol.h"
@@ -69,7 +70,7 @@ static bool handle_message(
         if (!icipc_protocol_parse_request(buffer, size, &name, &args)) {
                 const char *msg = "could not parse request";
                 const size_t s = icipc_protocol_calculate_reply_error_size(msg);
-                uint8_t b[s];
+                uint8_t *b = alloca(s);
                 icipc_protocol_build_reply_error(b, s, msg);
                 return icipc_socket_write(sender_fd, b, s) == (ssize_t) s;
         }
@@ -234,7 +235,7 @@ bool icipc_server_reply_ok(
                 int client_fd,
                 const struct icipc_data *value) {
         const size_t s = icipc_protocol_calculate_reply_ok_size(value);
-        uint8_t b[s];
+        uint8_t *b = alloca(s);
         icipc_protocol_build_reply_ok(b, s, value);
         return icipc_socket_write(client_fd, b, s) == (ssize_t) s;
 }
@@ -247,7 +248,7 @@ bool icipc_server_reply_error(
                 return false;
 
         const size_t s = icipc_protocol_calculate_reply_error_size(msg);
-        uint8_t b[s];
+        uint8_t *b = alloca(s);
         icipc_protocol_build_reply_error(b, s, msg);
         return icipc_socket_write(client_fd, b, s) == (ssize_t) s;
 }
diff --git a/lib/utils.c b/lib/utils.c
index 4d91241..37bcce9 100644
--- a/lib/utils.c
+++ b/lib/utils.c
@@ -91,7 +91,6 @@ int icipc_construct_socket_path(const char *name, char *buf, size_t buf_size) {
         bool path_is_absolute;
         const char *runtime_dir = NULL;
         struct passwd pwd, *result = NULL;
-        char buffer[4096];
         int name_size;
 
         path_is_absolute = name[0] == '/';
@@ -105,8 +104,12 @@ int icipc_construct_socket_path(const char *name, char *buf, size_t buf_size) {
                 if (runtime_dir == NULL)
                         runtime_dir = getenv("USERPROFILE");
                 if (runtime_dir == NULL) {
+                        long bufsize = sysconf(_SC_GETPW_R_SIZE_MAX);
+                        if (bufsize == -1)
+                                bufsize = 4096;
+                        char *buffer = alloca(bufsize);
                         if (getpwuid_r
-                            (getuid(), &pwd, buffer, sizeof(buffer),
+                            (getuid(), &pwd, buffer, bufsize,
                              &result) == 0)
                                 runtime_dir = result ? result->pw_dir : NULL;
                 }
-- 
cgit 1.2.3-korg