commit f694a443fc35e91d301470c60a7989d4fbd6de71 Author: Nick Mathewson nickm@torproject.org Date: Wed May 14 22:49:38 2014 -0400

Improved comments on bug11946 fix --- src/common/compat.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/common/compat.c b/src/common/compat.c index 65446b5..b95609a 100644 --- a/src/common/compat.c +++ b/src/common/compat.c @@ -1703,8 +1703,14 @@ log_credential_status(void) #endif

#ifndef _WIN32 +/** Cached struct from the last getpwname() call we did successfully. */ static struct passwd *passwd_cached = NULL;

+/** Helper: copy a struct passwd object. + * + * We only copy the fields pw_uid, pw_gid, pw_name, pw_dir. Tor doesn't use + * any others, and I don't want to run into incompatibilities. + */ static struct passwd * tor_passwd_dup(const struct passwd *pw) { @@ -1719,6 +1725,7 @@ tor_passwd_dup(const struct passwd *pw) return new_pw; }

+/** Helper: free one of our cached 'struct passwd' values. */ static void tor_passwd_free(struct passwd *pw) { @@ -1731,7 +1738,14 @@ tor_passwd_free(struct passwd *pw) }

/** Wrapper around getpwnam() that caches result. Used so that we don't need - * to give the sandbox access to /etc/passwd. */ + * to give the sandbox access to /etc/passwd. + * + * The following fields alone will definitely be copied in the output: pw_uid, + * pw_gid, pw_name, pw_dir. Other fields are not present in cached values. + * + * When called with a NULL argument, this function clears storage associated + * with static variables it uses. + **/ const struct passwd * tor_getpwnam(const char *username) { @@ -1763,7 +1777,11 @@ tor_getpwnam(const char *username)

/** Wrapper around getpwnam() that can use cached result from * tor_getpwnam(). Used so that we don't need to give the sandbox access to - * /etc/passwd. */ + * /etc/passwd. + * + * The following fields alone will definitely be copied in the output: pw_uid, + * pw_gid, pw_name, pw_dir. Other fields are not present in cached values. + */ const struct passwd * tor_getpwuid(uid_t uid) {