From: Andre Noll <maan@tuebingen.mpg.de>
Date: Sun, 12 May 2024 01:09:58 +0000 (+0200)
Subject: Consult $HOME and $LOGNAME rather than calling getpwuid(),
X-Git-Tag: v1.0.2~26
X-Git-Url: http://git.tue.mpg.de/?a=commitdiff_plain;h=5244a093e7fb783f1e9616baad572ff1cb515cb6;p=dss.git

Consult $HOME and $LOGNAME rather than calling getpwuid(),

Quiting getpwnam(3):

    An application that wants to determine its user’s home
    directory should inspect the value of HOME (rather than the value
    getpwuid(getuid())->pw_dir) since this allows the user to modify
    their notion of "the home directory" during a login session.

The old behaviour of get_homedir() to return "/tmp" in the error case
is misleading at best, so abort in this case.
---

diff --git a/str.c b/str.c
index 1377630..eeb635c 100644
--- a/str.c
+++ b/str.c
@@ -151,16 +151,19 @@ __must_check __printf_1_2 __malloc char *make_message(const char *fmt, ...)
 	}
 }
 
-/**
+/*
  * Get the home directory of the current user.
  *
- * \return A dynamically allocated string that must be freed by the caller. If
- * the home directory could not be found, this function returns "/tmp".
+ * Returns a dynamically allocated string that must be freed by the caller. If
+ * the HOME environment variable is unset or empty, the function aborts.
  */
 __must_check __malloc char *get_homedir(void)
 {
-	struct passwd *pw = getpwuid(getuid());
-	return dss_strdup(pw? pw->pw_dir : "/tmp");
+	const char *home = getenv("HOME");
+	if (home && *home)
+		return dss_strdup(home);
+	DSS_EMERG_LOG(("fatal: HOME is unset or empty\n"));
+	exit(EXIT_FAILURE);
 }
 
 /**
@@ -192,19 +195,18 @@ int dss_atoi64(const char *str, int64_t *value)
 	return 1;
 }
 
-/**
+/*
  * Get the logname of the current user.
  *
- * \return A dynamically allocated string that must be freed by the caller. On
- * errors, the string "unknown user" is returned, i.e. this function never
- * returns \p NULL.
- *
- * \sa getpwuid(3).
+ * Returns a dynamically allocated string that must be freed by the caller. On
+ * errors, the string "unknown" is returned. This function never returns NULL.
  */
 __must_check __malloc char *dss_logname(void)
 {
-	struct passwd *pw = getpwuid(getuid());
-	return dss_strdup(pw? pw->pw_name : "unknown_user");
+	const char *logname = getenv("LOGNAME");
+	if (!logname && !*logname)
+		logname = "unknown";
+	return dss_strdup(logname);
 }
 
 /**