[PATCH] pokefmt,poked: s/strerror/strerror_r/

[Mohammad-Reza Nabipoor]

`strerror' function is not thread-safe.  This commit replace them
with POSIX-compliant `strerror_r' function.

2024-02-15  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>

        * bootstrap.conf (gnulib_modules): s/strerror/strerror_r-posix/.
        * pokefmt/pokefmt.l (err): Use `strerror_r'.
        * poked/poked.c (err): Likewise.
        * poked/usock.c (errorf): New function.
        (usock_handle_srv): Use `errorf' to make the buffer.
        (usock_handle_notif): Likewise.
        (usock_serve): Likewise.
---

Hi Jose.

Please review the changes.  At the moment, I'm too tired to convince myself
that the changes are correct :D


Regards,
Mohammad-Reza


 ChangeLog         | 10 +++++++++
 bootstrap.conf    |  2 +-
 poked/poked.c     |  5 ++++-
 poked/usock.c     | 52 +++++++++++++++++++++++++++++++++++++++--------
 pokefmt/pokefmt.l |  5 ++++-
 5 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index f101815d..414fb7fc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+2024-02-15  Mohammad-Reza Nabipoor  <mnabipoor@gnu.org>
+
+       * bootstrap.conf (gnulib_modules): s/strerror/strerror_r-posix/.
+       * pokefmt/pokefmt.l (err): Use `strerror_r'.
+       * poked/poked.c (err): Likewise.
+       * poked/usock.c (errorf): New function.
+       (usock_handle_srv): Use `errorf' to make the buffer.
+       (usock_handle_notif): Likewise.
+       (usock_serve): Likewise.
+
 2024-02-12  Jose E. Marchesi  <jemarch@gnu.org>
 
        * bootstrap.conf (gnulib_modules): Import regex module from
diff --git a/bootstrap.conf b/bootstrap.conf
index 72f13d4a..30245a6f 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -49,7 +49,7 @@ gnulib_modules="
   stdarg
   stdbool
   strchrnul
-  strerror
+  strerror_r-posix
   streq
   sys_ioctl
   terminfo
diff --git a/poked/poked.c b/poked/poked.c
index 04120660..43deaf08 100644
--- a/poked/poked.c
+++ b/poked/poked.c
@@ -51,11 +51,14 @@ static void
 err(int eval, const char *fmt, ...)
 {
   va_list ap;
+  char buf[128];
 
   va_start (ap, fmt);
   vfprintf (stderr, fmt, ap);
   va_end (ap);
-  fprintf (stderr, ": %s\n", strerror (errno));
+  buf[0] = '\0';
+  strerror_r (errno, buf, sizeof (buf));
+  fprintf (stderr, ": %s\n", buf);
   exit (eval);
 }
 
diff --git a/poked/usock.c b/poked/usock.c
index f1d3dc62..822a5382 100644
--- a/poked/usock.c
+++ b/poked/usock.c
@@ -130,6 +130,43 @@ write_n_bytes (int fd, unsigned char *data, size_t *len, 
size_t cap)
 
 //---
 
+static void
+errorf (int errnum, char *buf, size_t bufsz, const char *fmt, ...)
+{
+  int n;
+  va_list ap;
+
+  assert (buf);
+  assert (bufsz);
+
+  va_start (ap, fmt);
+  n = vsnprintf (buf, bufsz, fmt, ap);
+  va_end (ap);
+
+  assert (n > 0);
+  /* Worst case in release build.  */
+  if (n < 0)
+    {
+      buf[0] = '\0';
+      n = 0;
+    }
+
+  bufsz -= n;
+  buf += n;
+
+  if (bufsz < 3)
+    return;
+  buf[0] = ':';
+  buf[1] = ' ';
+  buf[2] = '\0';
+  bufsz -= 2;
+  buf += 2;
+
+  strerror_r (errnum, buf, bufsz);
+}
+
+//---
+
 // CHKME proper use
 #define USOCK_DIR_UNK 0
 #define USOCK_DIR_IN 1
@@ -368,8 +405,8 @@ usock_handle_srv (struct usock *u, struct pollfd *pfds)
             break;
           if (errno == EINTR)
             continue;
-          snprintf (u->errbuf, USOCK_ERRBUF_SIZE, "[%s] accept() failed: %s",
-                    __func__, strerror (errno));
+          errorf (errno, u->errbuf, USOCK_ERRBUF_SIZE, "[%s] accept() failed",
+                  __func__);
           return USOCK_HANDLE_SRV_NOK;
         }
       if (u->nclients == USOCK_CLIENTS_MAX)
@@ -380,9 +417,8 @@ usock_handle_srv (struct usock *u, struct pollfd *pfds)
         }
       if (fcntl (fd, F_SETFL, O_NONBLOCK) == -1)
         {
-          snprintf (u->errbuf, USOCK_ERRBUF_SIZE,
-                    "[%s] fcntl(%d, O_NONBLOCK) failed: %s", __func__, fd,
-                    strerror (errno));
+          errorf (errno, u->errbuf, USOCK_ERRBUF_SIZE,
+                  "[%s] fcntl(%d, O_NONBLOCK) failed", __func__, fd);
           return USOCK_HANDLE_SRV_NOK;
         }
       c = &u->clients[u->nclients];
@@ -424,7 +460,8 @@ usock_handle_notif (struct usock *u, struct pollfd *pfds)
         {
           if (errno == EAGAIN || errno == EWOULDBLOCK)
             break;
-          snprintf (u->errbuf, USOCK_ERRBUF_SIZE, "read(pipefd[0]) failed");
+          errorf (errno, u->errbuf, USOCK_ERRBUF_SIZE,
+                  "read(pipefd[0]) failed");
           return USOCK_HANDLE_NOTIF_NOK;
         }
     }
@@ -573,8 +610,7 @@ usock_serve (struct usock *u)
         {
           if (errno == EINTR || errno == EAGAIN || errno == EWOULDBLOCK)
             continue;
-          snprintf (u->errbuf, USOCK_ERRBUF_SIZE, "poll() failed: %s",
-                    strerror (errno));
+          errorf (errno, u->errbuf, USOCK_ERRBUF_SIZE, "poll() failed");
           ret = USOCK_SERVE_NOK;
           break;
         }
diff --git a/pokefmt/pokefmt.l b/pokefmt/pokefmt.l
index 69c854ae..7a5c81b9 100644
--- a/pokefmt/pokefmt.l
+++ b/pokefmt/pokefmt.l
@@ -278,11 +278,14 @@ static void
 err (int eval, const char *fmt, ...)
 {
   va_list ap;
+  char buf[128];
 
   va_start (ap, fmt);
   vfprintf (stderr, fmt, ap);
   va_end (ap);
-  fprintf (stderr, ": %s\n", strerror (errno));
+  buf[0] = '\0';
+  strerror_r (errno, buf, sizeof (buf));
+  fprintf (stderr, ": %s\n", buf);
   exit (eval);
 }
 
-- 
2.43.0