Adding upstream version 1.9.13p3.upstream/1.9.13p3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1907 insertions, 0 deletions

diff --git a/logsrvd/logsrvd_conf.c b/logsrvd/logsrvd_conf.c
new file mode 100644
index 0000000..1cde0ba
--- /dev/null
+++ b/logsrvd/logsrvd_conf.c
@@ -0,0 +1,1907 @@
+/*
+ * SPDX-License-Identifier: ISC
+ *
+ * Copyright (c) 2019-2022 Todd C. Miller <Todd.Miller@sudo.ws>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/*
+ * This is an open source non-commercial project. Dear PVS-Studio, please check it.
+ * PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
+ */
+
+#include <config.h>
+
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+
+#include <errno.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <netdb.h>
+#ifdef HAVE_STDBOOL_H
+# include <stdbool.h>
+#else
+# include "compat/stdbool.h"
+#endif
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <time.h>
+#include <unistd.h>
+#include <grp.h>
+#include <pwd.h>
+#ifndef HAVE_GETADDRINFO
+# include "compat/getaddrinfo.h"
+#endif
+
+#include "pathnames.h"
+#include "sudo_compat.h"
+#include "sudo_debug.h"
+#include "sudo_eventlog.h"
+#include "sudo_fatal.h"
+#include "sudo_gettext.h"
+#include "sudo_iolog.h"
+#include "sudo_util.h"
+
+#include "logsrvd.h"
+
+#if defined(HAVE_OPENSSL)
+# define DEFAULT_CA_CERT_PATH       "/etc/ssl/sudo/cacert.pem"
+# define DEFAULT_SERVER_CERT_PATH   "/etc/ssl/sudo/certs/logsrvd_cert.pem"
+# define DEFAULT_SERVER_KEY_PATH    "/etc/ssl/sudo/private/logsrvd_key.pem"
+
+/* Evaluates to true if at least one TLS field is set, else false. */
+# define TLS_CONFIGURED(_s)						\
+    ((_s).tls_key_path != NULL || (_s).tls_cert_path != NULL ||		\
+     (_s).tls_cacert_path != NULL || (_s).tls_dhparams_path != NULL ||	\
+     (_s).tls_ciphers_v12 != NULL || (_s).tls_ciphers_v13 != NULL ||	\
+     (_s).tls_verify != -1)
+
+/* Evaluates to the relay-specific TLS setting, falling back to server. */
+# define TLS_RELAY_STR(_c, _f)	\
+    ((_c)->relay._f != NULL ? (_c)->relay._f : (_c)->server._f)
+
+# define TLS_RELAY_INT(_c, _f)	\
+    ((_c)->relay._f != -1 ? (_c)->relay._f : (_c)->server._f)
+#endif
+
+enum server_log_type {
+    SERVER_LOG_NONE,
+    SERVER_LOG_STDERR,
+    SERVER_LOG_SYSLOG,
+    SERVER_LOG_FILE
+};
+
+struct logsrvd_config;
+typedef bool (*logsrvd_conf_cb_t)(struct logsrvd_config *, const char *, size_t);
+
+struct logsrvd_config_entry {
+    const char *conf_str;
+    logsrvd_conf_cb_t setter;
+    size_t offset;
+};
+
+struct logsrvd_config_section {
+    const char *name;
+    struct logsrvd_config_entry *entries;
+};
+
+struct address_list_container {
+    unsigned int refcnt;
+    struct server_address_list addrs;
+};
+
+static struct logsrvd_config {
+    struct logsrvd_config_server {
+        struct address_list_container addresses;
+        struct timespec timeout;
+        bool tcp_keepalive;
+	enum server_log_type log_type;
+	FILE *log_stream;
+	char *log_file;
+	char *pid_file;
+#if defined(HAVE_OPENSSL)
+	char *tls_key_path;
+	char *tls_cert_path;
+	char *tls_cacert_path;
+	char *tls_dhparams_path;
+	char *tls_ciphers_v12;
+	char *tls_ciphers_v13;
+	int tls_check_peer;
+	int tls_verify;
+	SSL_CTX *ssl_ctx;
+#endif
+    } server;
+    struct logsrvd_config_relay {
+        struct address_list_container relays;
+        struct timespec connect_timeout;
+        struct timespec timeout;
+	time_t retry_interval;
+	char *relay_dir;
+        bool tcp_keepalive;
+	bool store_first;
+#if defined(HAVE_OPENSSL)
+	char *tls_key_path;
+	char *tls_cert_path;
+	char *tls_cacert_path;
+	char *tls_dhparams_path;
+	char *tls_ciphers_v12;
+	char *tls_ciphers_v13;
+	int tls_check_peer;
+	int tls_verify;
+	SSL_CTX *ssl_ctx;
+#endif
+    } relay;
+    struct logsrvd_config_iolog {
+	bool compress;
+	bool flush;
+	bool gid_set;
+	bool log_passwords;
+	uid_t uid;
+	gid_t gid;
+	mode_t mode;
+	unsigned int maxseq;
+	char *iolog_dir;
+	char *iolog_file;
+	void *passprompt_regex;
+    } iolog;
+    struct logsrvd_config_eventlog {
+	int log_type;
+        bool log_exit;
+	enum eventlog_format log_format;
+    } eventlog;
+    struct logsrvd_config_syslog {
+	unsigned int maxlen;
+	int server_facility;
+	int facility;
+	int acceptpri;
+	int rejectpri;
+	int alertpri;
+    } syslog;
+    struct logsrvd_config_logfile {
+	char *path;
+	char *time_format;
+	FILE *stream;
+    } logfile;
+} *logsrvd_config;
+
+static bool logsrvd_warn_enable_stderr = true;
+
+/* eventlog getters */
+bool
+logsrvd_conf_log_exit(void)
+{
+    return logsrvd_config->eventlog.log_exit;
+}
+
+/* iolog getters */
+uid_t
+logsrvd_conf_iolog_uid(void)
+{
+    return logsrvd_config->iolog.uid;
+}
+
+gid_t
+logsrvd_conf_iolog_gid(void)
+{
+    return logsrvd_config->iolog.gid;
+}
+
+mode_t
+logsrvd_conf_iolog_mode(void)
+{
+    return logsrvd_config->iolog.mode;
+}
+
+const char *
+logsrvd_conf_iolog_dir(void)
+{
+    return logsrvd_config->iolog.iolog_dir;
+}
+
+const char *
+logsrvd_conf_iolog_file(void)
+{
+    return logsrvd_config->iolog.iolog_file;
+}
+
+bool
+logsrvd_conf_iolog_log_passwords(void)
+{
+    return logsrvd_config->iolog.log_passwords;
+}
+
+void *
+logsrvd_conf_iolog_passprompt_regex(void)
+{
+    return logsrvd_config->iolog.passprompt_regex;
+}
+
+/* server getters */
+struct server_address_list *
+logsrvd_conf_server_listen_address(void)
+{
+    return &logsrvd_config->server.addresses.addrs;
+}
+
+bool
+logsrvd_conf_server_tcp_keepalive(void)
+{
+    return logsrvd_config->server.tcp_keepalive;
+}
+
+const char *
+logsrvd_conf_pid_file(void)
+{
+    return logsrvd_config->server.pid_file;
+}
+
+struct timespec *
+logsrvd_conf_server_timeout(void)
+{
+    if (sudo_timespecisset(&logsrvd_config->server.timeout)) {
+        return &logsrvd_config->server.timeout;
+    }
+
+    return NULL;
+}
+
+#if defined(HAVE_OPENSSL)
+SSL_CTX *
+logsrvd_server_tls_ctx(void)
+{
+    return logsrvd_config->server.ssl_ctx;
+}
+
+bool
+logsrvd_conf_server_tls_check_peer(void)
+{
+    return logsrvd_config->server.tls_check_peer;
+}
+#endif
+
+/* relay getters */
+struct server_address_list *
+logsrvd_conf_relay_address(void)
+{
+    return &logsrvd_config->relay.relays.addrs;
+}
+
+const char *
+logsrvd_conf_relay_dir(void)
+{
+    return logsrvd_config->relay.relay_dir;
+}
+
+bool
+logsrvd_conf_relay_store_first(void)
+{
+    return logsrvd_config->relay.store_first;
+}
+
+bool
+logsrvd_conf_relay_tcp_keepalive(void)
+{
+    return logsrvd_config->relay.tcp_keepalive;
+}
+
+struct timespec *
+logsrvd_conf_relay_timeout(void)
+{
+    if (sudo_timespecisset(&logsrvd_config->relay.timeout)) {
+        return &logsrvd_config->relay.timeout;
+    }
+
+    return NULL;
+}
+
+struct timespec *
+logsrvd_conf_relay_connect_timeout(void)
+{
+    if (sudo_timespecisset(&logsrvd_config->relay.connect_timeout)) {
+        return &logsrvd_config->relay.connect_timeout;
+    }
+
+    return NULL;
+}
+
+time_t
+logsrvd_conf_relay_retry_interval(void)
+{
+    return logsrvd_config->relay.retry_interval;
+}
+
+#if defined(HAVE_OPENSSL)
+SSL_CTX *
+logsrvd_relay_tls_ctx(void)
+{
+    if (logsrvd_config->relay.ssl_ctx != NULL)
+	return logsrvd_config->relay.ssl_ctx;
+    return logsrvd_config->server.ssl_ctx;
+}
+
+bool
+logsrvd_conf_relay_tls_check_peer(void)
+{
+    if (logsrvd_config->relay.tls_check_peer != -1)
+	return logsrvd_config->relay.tls_check_peer;
+    return logsrvd_config->server.tls_check_peer;
+}
+#endif
+
+/* I/O log callbacks */
+static bool
+cb_iolog_dir(struct logsrvd_config *config, const char *path, size_t offset)
+{
+    debug_decl(cb_iolog_dir, SUDO_DEBUG_UTIL);
+
+    free(config->iolog.iolog_dir);
+    if ((config->iolog.iolog_dir = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_file(struct logsrvd_config *config, const char *path, size_t offset)
+{
+    debug_decl(cb_iolog_file, SUDO_DEBUG_UTIL);
+
+    free(config->iolog.iolog_file);
+    if ((config->iolog.iolog_file = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_compress(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_iolog_compress, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->iolog.compress = val;
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_log_passwords(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_iolog_log_passwords, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->iolog.log_passwords = val;
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_flush(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_iolog_flush, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->iolog.flush = val;
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_user(struct logsrvd_config *config, const char *user, size_t offset)
+{
+    struct passwd *pw;
+    debug_decl(cb_iolog_user, SUDO_DEBUG_UTIL);
+
+    if ((pw = getpwnam(user)) == NULL) {
+	sudo_warnx(U_("unknown user %s"), user);
+	debug_return_bool(false);
+    }
+    config->iolog.uid = pw->pw_uid;
+    if (!config->iolog.gid_set)
+	config->iolog.gid = pw->pw_gid;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_group(struct logsrvd_config *config, const char *group, size_t offset)
+{
+    struct group *gr;
+    debug_decl(cb_iolog_group, SUDO_DEBUG_UTIL);
+
+    if ((gr = getgrnam(group)) == NULL) {
+	sudo_warnx(U_("unknown group %s"), group);
+	debug_return_bool(false);
+    }
+    config->iolog.gid = gr->gr_gid;
+    config->iolog.gid_set = true;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_mode(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    const char *errstr;
+    mode_t mode;
+    debug_decl(cb_iolog_mode, SUDO_DEBUG_UTIL);
+
+    mode = sudo_strtomode(str, &errstr);
+    if (errstr != NULL) {
+	sudo_warnx(U_("unable to parse iolog mode %s"), str);
+	debug_return_bool(false);
+    }
+    config->iolog.mode = mode;
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_maxseq(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    const char *errstr;
+    unsigned int value;
+    debug_decl(cb_iolog_maxseq, SUDO_DEBUG_UTIL);
+
+    value = sudo_strtonum(str, 0, SESSID_MAX, &errstr);
+    if (errstr != NULL) {
+        if (errno != ERANGE) {
+	    sudo_warnx(U_("invalid value for %s: %s"), "maxseq", errstr);
+            debug_return_bool(false);
+        }
+        /* Out of range, clamp to SESSID_MAX as documented. */
+        value = SESSID_MAX;
+    }
+    config->iolog.maxseq = value;
+    debug_return_bool(true);
+}
+
+static bool
+cb_iolog_passprompt_regex(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    debug_decl(cb_iolog_passprompt_regex, SUDO_DEBUG_UTIL);
+
+    if (config->iolog.passprompt_regex == NULL) {
+	/* Lazy alloc of the passprompt regex handle. */
+	config->iolog.passprompt_regex = iolog_pwfilt_alloc();
+	if (config->iolog.passprompt_regex == NULL)
+	    debug_return_bool(false);
+    }
+    debug_return_bool(iolog_pwfilt_add(config->iolog.passprompt_regex, str));
+}
+
+/* Server callbacks */
+static bool
+append_address(struct server_address_list *addresses, const char *str,
+    bool allow_wildcard)
+{
+    struct addrinfo hints, *res, *res0 = NULL;
+    char *sa_str = NULL, *sa_host = NULL;
+    char *copy, *host, *port;
+    bool tls, ret = false;
+    int error;
+    debug_decl(append_address, SUDO_DEBUG_UTIL);
+
+    if ((copy = strdup(str)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+
+    /* Parse host[:port] */
+    if (!iolog_parse_host_port(copy, &host, &port, &tls, DEFAULT_PORT,
+	    DEFAULT_PORT_TLS))
+	goto done;
+    if (host[0] == '*' && host[1] == '\0') {
+	if (!allow_wildcard)
+	    goto done;
+	host = NULL;
+    }
+
+#if !defined(HAVE_OPENSSL)
+    if (tls) {
+	sudo_warnx("%s", U_("TLS not supported"));
+	goto done;
+    }
+#endif
+
+    /* Only make a single copy of the string + host for all addresses. */
+    if ((sa_str = sudo_rcstr_dup(str)) == NULL)	{
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	goto done;
+    }
+    if (host != NULL && (sa_host = sudo_rcstr_dup(host)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	goto done;
+    }
+
+    /* Resolve host (and port if it is a service). */
+    memset(&hints, 0, sizeof(hints));
+    hints.ai_family = AF_UNSPEC;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = AI_PASSIVE;
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+    hints.ai_flags |= AI_NUMERICSERV;
+#endif
+    error = getaddrinfo(host, port, &hints, &res0);
+    if (error != 0) {
+	sudo_gai_warn(error, U_("%s:%s"), host ? host : "*", port);
+	goto done;
+    }
+    for (res = res0; res != NULL; res = res->ai_next) {
+	struct server_address *addr;
+
+	if ((addr = malloc(sizeof(*addr))) == NULL) {
+	    sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	    goto done;
+	}
+	addr->sa_str = sudo_rcstr_addref(sa_str);
+	addr->sa_host = sudo_rcstr_addref(sa_host);
+
+	memcpy(&addr->sa_un, res->ai_addr, res->ai_addrlen);
+	addr->sa_size = res->ai_addrlen;
+	addr->tls = tls;
+	TAILQ_INSERT_TAIL(addresses, addr, entries);
+    }
+
+    ret = true;
+done:
+    sudo_rcstr_delref(sa_str);
+    sudo_rcstr_delref(sa_host);
+    if (res0 != NULL)
+	freeaddrinfo(res0);
+    free(copy);
+    debug_return_bool(ret);
+}
+
+static bool
+cb_server_listen_address(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    return append_address(&config->server.addresses.addrs, str, true);
+}
+
+static bool
+cb_server_timeout(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    time_t timeout;
+    const char *errstr;
+    debug_decl(cb_server_timeout, SUDO_DEBUG_UTIL);
+
+    timeout = sudo_strtonum(str, 0, TIME_T_MAX, &errstr);
+    if (errstr != NULL)
+	debug_return_bool(false);
+
+    config->server.timeout.tv_sec = timeout;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_server_keepalive(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_server_keepalive, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->server.tcp_keepalive = val;
+    debug_return_bool(true);
+}
+
+static bool
+cb_server_pid_file(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char *copy = NULL;
+    debug_decl(cb_server_pid_file, SUDO_DEBUG_UTIL);
+
+    /* An empty value means to disable the pid file. */
+    if (*str != '\0') {
+	if (*str != '/') {
+	    sudo_warnx(U_("%s: not a fully qualified path"), str);
+	    debug_return_bool(false);
+	}
+	if ((copy = strdup(str)) == NULL) {
+	    sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	    debug_return_bool(false);
+	}
+    }
+
+    free(config->server.pid_file);
+    config->server.pid_file = copy;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_server_log(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char *copy = NULL;
+    enum server_log_type log_type = SERVER_LOG_NONE;
+    debug_decl(cb_server_log, SUDO_DEBUG_UTIL);
+
+    /* An empty value means to disable the server log. */
+    if (*str != '\0') {
+	if (*str == '/') {
+	    log_type = SERVER_LOG_FILE;
+	    if ((copy = strdup(str)) == NULL) {
+		sudo_warnx(U_("%s: %s"), __func__,
+		    U_("unable to allocate memory"));
+		debug_return_bool(false);
+	    }
+	} else if (strcmp(str, "stderr") == 0) {
+	    log_type = SERVER_LOG_STDERR;
+	} else if (strcmp(str, "syslog") == 0) {
+	    log_type = SERVER_LOG_SYSLOG;
+	} else {
+	    debug_return_bool(false);
+	}
+    }
+
+    free(config->server.log_file);
+    config->server.log_file = copy;
+    config->server.log_type = log_type;
+
+    debug_return_bool(true);
+}
+
+#if defined(HAVE_OPENSSL)
+static bool
+cb_tls_key(struct logsrvd_config *config, const char *path, size_t offset)
+{
+    char **p = (char **)((char *)config + offset);
+    debug_decl(cb_tls_key, SUDO_DEBUG_UTIL);
+
+    free(*p);
+    if ((*p = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_cacert(struct logsrvd_config *config, const char *path, size_t offset)
+{
+    char **p = (char **)((char *)config + offset);
+    debug_decl(cb_tls_cacert, SUDO_DEBUG_UTIL);
+
+    free(*p);
+    if ((*p = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_cert(struct logsrvd_config *config, const char *path, size_t offset)
+{
+    char **p = (char **)((char *)config + offset);
+    debug_decl(cb_tls_cert, SUDO_DEBUG_UTIL);
+
+    free(*p);
+    if ((*p = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_dhparams(struct logsrvd_config *config, const char *path, size_t offset)
+{
+    char **p = (char **)((char *)config + offset);
+    debug_decl(cb_tls_dhparams, SUDO_DEBUG_UTIL);
+
+    free(*p);
+    if ((*p = strdup(path)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_ciphers12(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char **p = (char **)((char *)config + offset);
+    debug_decl(cb_tls_ciphers12, SUDO_DEBUG_UTIL);
+
+    free(*p);
+    if ((*p = strdup(str)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_ciphers13(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char **p = (char **)((char *)config + offset);
+    debug_decl(cb_tls_ciphers13, SUDO_DEBUG_UTIL);
+
+    free(*p);
+    if ((*p = strdup(str)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+        debug_return_bool(false);
+    }
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_verify(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int *p = (int *)((char *)config + offset);
+    int val;
+    debug_decl(cb_tls_verify, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    *p = val;
+    debug_return_bool(true);
+}
+
+static bool
+cb_tls_checkpeer(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int *p = (int *)((char *)config + offset);
+    int val;
+    debug_decl(cb_tls_checkpeer, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    *p = val;
+    debug_return_bool(true);
+}
+#endif
+
+/* relay callbacks */
+static bool
+cb_relay_host(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    return append_address(&config->relay.relays.addrs, str, false);
+}
+
+static bool
+cb_relay_timeout(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    time_t timeout;
+    const char *errstr;
+    debug_decl(cb_relay_timeout, SUDO_DEBUG_UTIL);
+
+    timeout = sudo_strtonum(str, 0, TIME_T_MAX, &errstr);
+    if (errstr != NULL)
+	debug_return_bool(false);
+
+    config->server.timeout.tv_sec = timeout;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_relay_connect_timeout(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    time_t timeout;
+    const char *errstr;
+    debug_decl(cb_relay_connect_timeout, SUDO_DEBUG_UTIL);
+
+    timeout = sudo_strtonum(str, 0, TIME_T_MAX, &errstr);
+    if (errstr != NULL)
+	debug_return_bool(false);
+
+    config->relay.connect_timeout.tv_sec = timeout;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_relay_dir(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char *copy = NULL;
+    debug_decl(cb_relay_dir, SUDO_DEBUG_UTIL);
+
+    if ((copy = strdup(str)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+
+    free(config->relay.relay_dir);
+    config->relay.relay_dir = copy;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_retry_interval(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    time_t interval;
+    const char *errstr;
+    debug_decl(cb_retry_interval, SUDO_DEBUG_UTIL);
+
+    interval = sudo_strtonum(str, 0, TIME_T_MAX, &errstr);
+    if (errstr != NULL)
+	debug_return_bool(false);
+
+    config->relay.retry_interval = interval;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_relay_store_first(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_relay_store_first, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->relay.store_first = val;
+    debug_return_bool(true);
+}
+
+static bool
+cb_relay_keepalive(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_relay_keepalive, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->relay.tcp_keepalive = val;
+    debug_return_bool(true);
+}
+
+/* eventlog callbacks */
+static bool
+cb_eventlog_type(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    debug_decl(cb_eventlog_type, SUDO_DEBUG_UTIL);
+
+    if (strcmp(str, "none") == 0)
+	config->eventlog.log_type = EVLOG_NONE;
+    else if (strcmp(str, "syslog") == 0)
+	config->eventlog.log_type = EVLOG_SYSLOG;
+    else if (strcmp(str, "logfile") == 0)
+	config->eventlog.log_type = EVLOG_FILE;
+    else
+	debug_return_bool(false);
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_eventlog_format(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    debug_decl(cb_eventlog_format, SUDO_DEBUG_UTIL);
+
+    if (strcmp(str, "json") == 0)
+	config->eventlog.log_format = EVLOG_JSON;
+    else if (strcmp(str, "sudo") == 0)
+	config->eventlog.log_format = EVLOG_SUDO;
+    else
+	debug_return_bool(false);
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_eventlog_exit(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int val;
+    debug_decl(cb_eventlog_exit, SUDO_DEBUG_UTIL);
+
+    if ((val = sudo_strtobool(str)) == -1)
+	debug_return_bool(false);
+
+    config->eventlog.log_exit = val;
+    debug_return_bool(true);
+}
+
+/* syslog callbacks */
+static bool
+cb_syslog_maxlen(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    unsigned int maxlen;
+    const char *errstr;
+    debug_decl(cb_syslog_maxlen, SUDO_DEBUG_UTIL);
+
+    maxlen = sudo_strtonum(str, 1, UINT_MAX, &errstr);
+    if (errstr != NULL)
+	debug_return_bool(false);
+
+    config->syslog.maxlen = maxlen;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_syslog_server_facility(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int logfac;
+    debug_decl(cb_syslog_server_facility, SUDO_DEBUG_UTIL);
+
+    if (!sudo_str2logfac(str, &logfac)) {
+	sudo_warnx(U_("unknown syslog facility %s"), str);
+	debug_return_bool(false);
+    }
+
+    config->syslog.server_facility = logfac;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_syslog_facility(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int logfac;
+    debug_decl(cb_syslog_facility, SUDO_DEBUG_UTIL);
+
+    if (!sudo_str2logfac(str, &logfac)) {
+	sudo_warnx(U_("unknown syslog facility %s"), str);
+	debug_return_bool(false);
+    }
+
+    config->syslog.facility = logfac;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_syslog_acceptpri(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int logpri;
+    debug_decl(cb_syslog_acceptpri, SUDO_DEBUG_UTIL);
+
+    if (!sudo_str2logpri(str, &logpri)) {
+	sudo_warnx(U_("unknown syslog priority %s"), str);
+	debug_return_bool(false);
+    }
+
+    config->syslog.acceptpri = logpri;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_syslog_rejectpri(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int logpri;
+    debug_decl(cb_syslog_rejectpri, SUDO_DEBUG_UTIL);
+
+    if (!sudo_str2logpri(str, &logpri)) {
+	sudo_warnx(U_("unknown syslog priority %s"), str);
+	debug_return_bool(false);
+    }
+
+    config->syslog.rejectpri = logpri;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_syslog_alertpri(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    int logpri;
+    debug_decl(cb_syslog_alertpri, SUDO_DEBUG_UTIL);
+
+    if (!sudo_str2logpri(str, &logpri)) {
+	sudo_warnx(U_("unknown syslog priority %s"), str);
+	debug_return_bool(false);
+    }
+
+    config->syslog.alertpri = logpri;
+
+    debug_return_bool(true);
+}
+
+/* logfile callbacks */
+static bool
+cb_logfile_path(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char *copy = NULL;
+    debug_decl(cb_logfile_path, SUDO_DEBUG_UTIL);
+
+    if (*str != '/') {
+	sudo_warnx(U_("%s: not a fully qualified path"), str);
+	debug_return_bool(false);
+    }
+    if ((copy = strdup(str)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+
+    free(config->logfile.path);
+    config->logfile.path = copy;
+
+    debug_return_bool(true);
+}
+
+static bool
+cb_logfile_time_format(struct logsrvd_config *config, const char *str, size_t offset)
+{
+    char *copy = NULL;
+    debug_decl(cb_logfile_time_format, SUDO_DEBUG_UTIL);
+
+    if ((copy = strdup(str)) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_bool(false);
+    }
+
+    free(config->logfile.time_format);
+    config->logfile.time_format = copy;
+
+    debug_return_bool(true);
+}
+
+void
+address_list_addref(struct server_address_list *al)
+{
+    struct address_list_container *container =
+	__containerof(al, struct address_list_container, addrs);
+    container->refcnt++;
+}
+
+void
+address_list_delref(struct server_address_list *al)
+{
+    struct address_list_container *container =
+	__containerof(al, struct address_list_container, addrs);
+    if (--container->refcnt == 0) {
+	struct server_address *addr;
+	while ((addr = TAILQ_FIRST(al))) {
+	    TAILQ_REMOVE(al, addr, entries);
+	    sudo_rcstr_delref(addr->sa_str);
+	    sudo_rcstr_delref(addr->sa_host);
+	    free(addr);
+	}
+    }
+}
+
+static struct logsrvd_config_entry server_conf_entries[] = {
+    { "listen_address", cb_server_listen_address },
+    { "timeout", cb_server_timeout },
+    { "tcp_keepalive", cb_server_keepalive },
+    { "pid_file", cb_server_pid_file },
+    { "server_log", cb_server_log },
+#if defined(HAVE_OPENSSL)
+    { "tls_key", cb_tls_key, offsetof(struct logsrvd_config, server.tls_key_path) },
+    { "tls_cacert", cb_tls_cacert, offsetof(struct logsrvd_config, server.tls_cacert_path) },
+    { "tls_cert", cb_tls_cert, offsetof(struct logsrvd_config, server.tls_cert_path) },
+    { "tls_dhparams", cb_tls_dhparams, offsetof(struct logsrvd_config, server.tls_dhparams_path) },
+    { "tls_ciphers_v12", cb_tls_ciphers12, offsetof(struct logsrvd_config, server.tls_ciphers_v12) },
+    { "tls_ciphers_v13", cb_tls_ciphers13, offsetof(struct logsrvd_config, server.tls_ciphers_v13) },
+    { "tls_checkpeer", cb_tls_checkpeer, offsetof(struct logsrvd_config, server.tls_check_peer) },
+    { "tls_verify", cb_tls_verify, offsetof(struct logsrvd_config, server.tls_verify) },
+#endif
+    { NULL }
+};
+
+static struct logsrvd_config_entry relay_conf_entries[] = {
+    { "relay_host", cb_relay_host },
+    { "timeout", cb_relay_timeout },
+    { "connect_timeout", cb_relay_connect_timeout },
+    { "relay_dir", cb_relay_dir },
+    { "retry_interval", cb_retry_interval },
+    { "store_first", cb_relay_store_first },
+    { "tcp_keepalive", cb_relay_keepalive },
+#if defined(HAVE_OPENSSL)
+    { "tls_key", cb_tls_key, offsetof(struct logsrvd_config, relay.tls_key_path) },
+    { "tls_cacert", cb_tls_cacert, offsetof(struct logsrvd_config, relay.tls_cacert_path) },
+    { "tls_cert", cb_tls_cert, offsetof(struct logsrvd_config, relay.tls_cert_path) },
+    { "tls_dhparams", cb_tls_dhparams, offsetof(struct logsrvd_config, relay.tls_dhparams_path) },
+    { "tls_ciphers_v12", cb_tls_ciphers12, offsetof(struct logsrvd_config, relay.tls_ciphers_v12) },
+    { "tls_ciphers_v13", cb_tls_ciphers13, offsetof(struct logsrvd_config, relay.tls_ciphers_v13) },
+    { "tls_checkpeer", cb_tls_checkpeer, offsetof(struct logsrvd_config, relay.tls_check_peer) },
+    { "tls_verify", cb_tls_verify, offsetof(struct logsrvd_config, relay.tls_verify) },
+#endif
+    { NULL }
+};
+
+static struct logsrvd_config_entry iolog_conf_entries[] = {
+    { "iolog_dir", cb_iolog_dir },
+    { "iolog_file", cb_iolog_file },
+    { "iolog_flush", cb_iolog_flush },
+    { "iolog_compress", cb_iolog_compress },
+    { "iolog_user", cb_iolog_user },
+    { "iolog_group", cb_iolog_group },
+    { "iolog_mode", cb_iolog_mode },
+    { "log_passwords", cb_iolog_log_passwords },
+    { "maxseq", cb_iolog_maxseq },
+    { "passprompt_regex", cb_iolog_passprompt_regex },
+    { NULL }
+};
+
+static struct logsrvd_config_entry eventlog_conf_entries[] = {
+    { "log_type", cb_eventlog_type },
+    { "log_format", cb_eventlog_format },
+    { "log_exit", cb_eventlog_exit },
+    { NULL }
+};
+
+static struct logsrvd_config_entry syslog_conf_entries[] = {
+    { "maxlen", cb_syslog_maxlen },
+    { "server_facility", cb_syslog_server_facility },
+    { "facility", cb_syslog_facility },
+    { "reject_priority", cb_syslog_rejectpri },
+    { "accept_priority", cb_syslog_acceptpri },
+    { "alert_priority", cb_syslog_alertpri },
+    { NULL }
+};
+
+static struct logsrvd_config_entry logfile_conf_entries[] = {
+    { "path", cb_logfile_path },
+    { "time_format", cb_logfile_time_format },
+    { NULL }
+};
+
+static struct logsrvd_config_section logsrvd_config_sections[] = {
+    { "server", server_conf_entries },
+    { "relay", relay_conf_entries },
+    { "iolog", iolog_conf_entries },
+    { "eventlog", eventlog_conf_entries },
+    { "syslog", syslog_conf_entries },
+    { "logfile", logfile_conf_entries },
+    { NULL }
+};
+
+static bool
+logsrvd_conf_parse(struct logsrvd_config *config, FILE *fp, const char *path)
+{
+    struct logsrvd_config_section *conf_section = NULL;
+    unsigned int lineno = 0;
+    size_t linesize = 0;
+    char *line = NULL;
+    bool ret = false;
+    debug_decl(logsrvd_conf_parse, SUDO_DEBUG_UTIL);
+
+    while (sudo_parseln(&line, &linesize, &lineno, fp, 0) != -1) {
+	struct logsrvd_config_entry *entry;
+	char *ep, *val;
+
+	/* Skip blank, comment or invalid lines. */
+	if (*line == '\0' || *line == ';')
+	    continue;
+
+	/* New section */
+	if (line[0] == '[') {
+	    char *cp, *section_name = line + 1;
+
+	    if ((ep = strchr(section_name, ']')) == NULL) {
+		sudo_warnx(U_("%s:%d unmatched '[': %s"),
+		    path, lineno, line);
+		goto done;
+	    }
+	    for (cp = ep + 1; *cp != '\0'; cp++) {
+		if (!isspace((unsigned char)*cp)) {
+		    sudo_warnx(U_("%s:%d garbage after ']': %s"),
+			path, lineno, line);
+		    goto done;
+		}
+	    }
+	    *ep = '\0';
+	    for (conf_section = logsrvd_config_sections; conf_section->name != NULL;
+		    conf_section++) {
+		if (strcasecmp(section_name, conf_section->name) == 0)
+		    break;
+	    }
+	    if (conf_section->name == NULL) {
+		sudo_warnx(U_("%s:%d invalid config section: %s"),
+		    path, lineno, section_name);
+		goto done;
+	    }
+	    continue;
+	}
+
+	if ((ep = strchr(line, '=')) == NULL) {
+	    sudo_warnx(U_("%s:%d invalid configuration line: %s"),
+		path, lineno, line);
+	    goto done;
+	}
+
+	if (conf_section == NULL) {
+	    sudo_warnx(U_("%s:%d expected section name: %s"),
+		path, lineno, line);
+	    goto done;
+	}
+
+	val = ep + 1;
+	while (isspace((unsigned char)*val))
+	    val++;
+	while (ep > line && isspace((unsigned char)ep[-1]))
+	    ep--;
+	*ep = '\0';
+	for (entry = conf_section->entries; entry->conf_str != NULL; entry++) {
+	    if (strcasecmp(line, entry->conf_str) == 0) {
+		if (!entry->setter(config, val, entry->offset)) {
+		    sudo_warnx(U_("invalid value for %s: %s"),
+			entry->conf_str, val);
+		    goto done;
+		}
+		break;
+	    }
+	}
+	if (entry->conf_str == NULL) {
+	    sudo_warnx(U_("%s:%d [%s] illegal key: %s"), path, lineno,
+		conf_section->name, line);
+	    goto done;
+	}
+    }
+    ret = true;
+
+done:
+    free(line);
+    debug_return_bool(ret);
+}
+
+static FILE *
+logsrvd_open_log_file(const char *path, int flags)
+{
+    mode_t oldmask;
+    FILE *fp = NULL;
+    const char *omode;
+    int fd;
+    debug_decl(logsrvd_open_log_file, SUDO_DEBUG_UTIL);
+
+    if (ISSET(flags, O_APPEND)) {
+	omode = "a";
+    } else {
+	omode = "w";
+    }
+    oldmask = umask(S_IRWXG|S_IRWXO);
+    fd = open(path, flags, S_IRUSR|S_IWUSR);
+    (void)umask(oldmask);
+    if (fd == -1 || (fp = fdopen(fd, omode)) == NULL) {
+	sudo_warn(U_("unable to open log file %s"), path);
+	if (fd != -1)
+	    close(fd);
+    }
+
+    debug_return_ptr(fp);
+}
+
+static FILE *
+logsrvd_open_eventlog(struct logsrvd_config *config)
+{
+    int flags;
+    debug_decl(logsrvd_open_eventlog, SUDO_DEBUG_UTIL);
+
+    /* Cannot append to a JSON file. */
+    if (config->eventlog.log_format == EVLOG_JSON) {
+	flags = O_RDWR|O_CREAT;
+    } else {
+	flags = O_WRONLY|O_APPEND|O_CREAT;
+    }
+    debug_return_ptr(logsrvd_open_log_file(config->logfile.path, flags));
+}
+
+static FILE *
+logsrvd_stub_open_log(int type, const char *logfile)
+{
+    /* Actual open already done by logsrvd_open_eventlog() */
+    return logsrvd_config->logfile.stream;
+}
+
+static void
+logsrvd_stub_close_log(int type, FILE *fp)
+{
+    return;
+}
+
+/* Set eventlog configuration settings from logsrvd config. */
+static void
+logsrvd_conf_eventlog_setconf(struct logsrvd_config *config)
+{
+    debug_decl(logsrvd_conf_eventlog_setconf, SUDO_DEBUG_UTIL);
+
+    eventlog_set_type(config->eventlog.log_type);
+    eventlog_set_format(config->eventlog.log_format);
+    eventlog_set_syslog_acceptpri(config->syslog.acceptpri); 
+    eventlog_set_syslog_rejectpri(config->syslog.rejectpri); 
+    eventlog_set_syslog_alertpri(config->syslog.alertpri); 
+    eventlog_set_syslog_maxlen(config->syslog.maxlen); 
+    eventlog_set_logpath(config->logfile.path);
+    eventlog_set_time_fmt(config->logfile.time_format);
+    eventlog_set_open_log(logsrvd_stub_open_log);
+    eventlog_set_close_log(logsrvd_stub_close_log);
+
+    debug_return;
+}
+
+/* Set I/O log configuration settings from logsrvd config. */
+static void
+logsrvd_conf_iolog_setconf(struct logsrvd_config *config)
+{
+    debug_decl(logsrvd_conf_iolog_setconf, SUDO_DEBUG_UTIL);
+
+    iolog_set_defaults();
+    iolog_set_compress(config->iolog.compress);
+    iolog_set_flush(config->iolog.flush);
+    iolog_set_owner(config->iolog.uid, config->iolog.gid);
+    iolog_set_mode(config->iolog.mode);
+    iolog_set_maxseq(config->iolog.maxseq);
+
+    debug_return;
+}
+
+/*
+ * Conversation function for use by sudo_warn/sudo_fatal.
+ * Logs to stdout/stderr.
+ */
+static int
+logsrvd_conv_stderr(int num_msgs, const struct sudo_conv_message msgs[],
+    struct sudo_conv_reply replies[], struct sudo_conv_callback *callback)
+{
+    int i;
+    debug_decl(logsrvd_conv_stderr, SUDO_DEBUG_UTIL);
+
+    for (i = 0; i < num_msgs; i++) {
+	if (fputs(msgs[i].msg, stderr) == EOF)
+	    debug_return_int(-1);
+    }
+
+    debug_return_int(0);
+}
+
+/*
+ * Conversation function for use by sudo_warn/sudo_fatal.
+ * Acts as a no-op log sink.
+ */
+static int
+logsrvd_conv_none(int num_msgs, const struct sudo_conv_message msgs[],
+    struct sudo_conv_reply replies[], struct sudo_conv_callback *callback)
+{
+    /* Also write to stderr if still in the foreground. */
+    if (logsrvd_warn_enable_stderr) {
+	(void)logsrvd_conv_stderr(num_msgs, msgs, replies, callback);
+    }
+
+    return 0;
+}
+
+/*
+ * Conversation function for use by sudo_warn/sudo_fatal.
+ * Logs to syslog.
+ */
+static int
+logsrvd_conv_syslog(int num_msgs, const struct sudo_conv_message msgs[],
+    struct sudo_conv_reply replies[], struct sudo_conv_callback *callback)
+{
+    char *buf = NULL, *cp = NULL;
+    const char *progname;
+    size_t proglen, bufsize = 0;
+    int i;
+    debug_decl(logsrvd_conv_syslog, SUDO_DEBUG_UTIL);
+
+    if (logsrvd_config == NULL) {
+	debug_return_int(logsrvd_conv_stderr(num_msgs, msgs, replies, callback));
+    }
+
+    /* Also write to stderr if still in the foreground. */
+    if (logsrvd_warn_enable_stderr) {
+	(void)logsrvd_conv_stderr(num_msgs, msgs, replies, callback);
+    }
+
+    /*
+     * Concat messages into a flag string that we can syslog.
+     */
+    progname = getprogname();
+    proglen = strlen(progname);
+    for (i = 0; i < num_msgs; i++) {
+	const char *msg = msgs[i].msg;
+	size_t len = strlen(msg);
+	size_t used = (size_t)(cp - buf);
+
+	/* Strip leading "sudo_logsrvd: " prefix. */
+	if (strncmp(msg, progname, proglen) == 0) {
+	    msg += proglen;
+	    len -= proglen;
+	    if (len == 0) {
+		/* Skip over ": " string that follows program name. */
+		if (i + 1 < num_msgs && strcmp(msgs[i + 1].msg, ": ") == 0) {
+		    i++;
+		    continue;
+		}
+	    } else if (msg[0] == ':' && msg[1] == ' ') {
+		/* Handle "progname: " */
+		msg += 2;
+		len -= 2;
+	    }
+	}
+
+	/* Strip off trailing newlines. */
+	while (len > 1 && msg[len - 1] == '\n')
+	    len--;
+	if (len == 0)
+	    continue;
+
+	if (len >= bufsize - used) {
+	    bufsize += 1024;
+	    char *tmp = realloc(buf, bufsize);
+	    if (tmp == NULL) {
+		sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+		free(buf);
+		debug_return_int(-1);
+	    }
+	    buf = tmp;
+	    cp = tmp + used;
+	}
+	memcpy(cp, msg, len);
+	cp[len] = '\0';
+	cp += len;
+    }
+    if (buf != NULL) {
+	openlog(progname, 0, logsrvd_config->syslog.server_facility);
+	syslog(LOG_ERR, "%s", buf);
+	free(buf);
+
+	/* Restore old syslog settings. */
+	if (logsrvd_config->eventlog.log_type == EVLOG_SYSLOG)
+	    openlog("sudo", 0, logsrvd_config->syslog.facility);
+    }
+
+    debug_return_int(0);
+}
+
+/*
+ * Conversation function for use by sudo_warn/sudo_fatal.
+ * Logs to an already-open log file.
+ */
+static int
+logsrvd_conv_logfile(int num_msgs, const struct sudo_conv_message msgs[],
+    struct sudo_conv_reply replies[], struct sudo_conv_callback *callback)
+{
+    const char *progname;
+    size_t proglen;
+    int i;
+    debug_decl(logsrvd_conv_logfile, SUDO_DEBUG_UTIL);
+
+    if (logsrvd_config == NULL) {
+	debug_return_int(logsrvd_conv_stderr(num_msgs, msgs, replies, callback));
+    }
+
+    /* Also write to stderr if still in the foreground. */
+    if (logsrvd_warn_enable_stderr) {
+	(void)logsrvd_conv_stderr(num_msgs, msgs, replies, callback);
+    }
+
+    if (logsrvd_config->server.log_stream == NULL) {
+	errno = EBADF;
+	debug_return_int(-1);
+    }
+
+    progname = getprogname();
+    proglen = strlen(progname);
+    for (i = 0; i < num_msgs; i++) {
+	const char *msg = msgs[i].msg;
+	size_t len = strlen(msg);
+
+	/* Strip leading "sudo_logsrvd: " prefix. */
+	if (strncmp(msg, progname, proglen) == 0) {
+	    msg += proglen;
+	    len -= proglen;
+	    if (len == 0) {
+		/* Skip over ": " string that follows program name. */
+		if (i + 1 < num_msgs && strcmp(msgs[i + 1].msg, ": ") == 0) {
+		    i++;
+		    continue;
+		}
+	    } else if (msg[0] == ':' && msg[1] == ' ') {
+		/* Handle "progname: " */
+		msg += 2;
+		len -= 2;
+	    }
+	}
+
+	if (fwrite(msg, len, 1, logsrvd_config->server.log_stream) != 1)
+	    debug_return_int(-1);
+    }
+
+    debug_return_int(0);
+}
+
+/* Free the specified struct logsrvd_config and its contents. */
+static void
+logsrvd_conf_free(struct logsrvd_config *config)
+{
+    debug_decl(logsrvd_conf_free, SUDO_DEBUG_UTIL);
+
+    if (config == NULL)
+	debug_return;
+
+    /* struct logsrvd_config_server */
+    address_list_delref(&config->server.addresses.addrs);
+    free(config->server.pid_file);
+    free(config->server.log_file);
+    if (config->server.log_stream != NULL)
+	fclose(config->server.log_stream);
+#if defined(HAVE_OPENSSL)
+    free(config->server.tls_key_path);
+    free(config->server.tls_cert_path);
+    free(config->server.tls_cacert_path);
+    free(config->server.tls_dhparams_path);
+    free(config->server.tls_ciphers_v12);
+    free(config->server.tls_ciphers_v13);
+
+    if (config->server.ssl_ctx != NULL)
+	SSL_CTX_free(config->server.ssl_ctx);
+#endif
+
+    /* struct logsrvd_config_relay */
+    address_list_delref(&config->relay.relays.addrs);
+    free(config->relay.relay_dir);
+#if defined(HAVE_OPENSSL)
+    free(config->relay.tls_key_path);
+    free(config->relay.tls_cert_path);
+    free(config->relay.tls_cacert_path);
+    free(config->relay.tls_dhparams_path);
+    free(config->relay.tls_ciphers_v12);
+    free(config->relay.tls_ciphers_v13);
+
+    if (config->relay.ssl_ctx != NULL)
+	SSL_CTX_free(config->relay.ssl_ctx);
+#endif
+
+    /* struct logsrvd_config_iolog */
+    free(config->iolog.iolog_dir);
+    free(config->iolog.iolog_file);
+    iolog_pwfilt_free(config->iolog.passprompt_regex);
+
+    /* struct logsrvd_config_logfile */
+    free(config->logfile.path);
+    free(config->logfile.time_format);
+    if (config->logfile.stream != NULL)
+	fclose(config->logfile.stream);
+
+    free(config);
+
+    debug_return;
+}
+
+/* Allocate a new struct logsrvd_config and set default values. */
+static struct logsrvd_config *
+logsrvd_conf_alloc(void)
+{
+    struct logsrvd_config *config;
+    debug_decl(logsrvd_conf_alloc, SUDO_DEBUG_UTIL);
+
+    if ((config = calloc(1, sizeof(*config))) == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	debug_return_ptr(NULL);
+    }
+
+    /* Relay defaults */
+    TAILQ_INIT(&config->relay.relays.addrs);
+    config->relay.relays.refcnt = 1;
+    config->relay.timeout.tv_sec = DEFAULT_SOCKET_TIMEOUT_SEC;
+    config->relay.connect_timeout.tv_sec = DEFAULT_SOCKET_TIMEOUT_SEC;
+    config->relay.tcp_keepalive = true;
+    config->relay.retry_interval = 30;
+    if (!cb_relay_dir(config, _PATH_SUDO_RELAY_DIR, 0))
+	goto bad;
+#if defined(HAVE_OPENSSL)
+    config->relay.tls_verify = -1;
+    config->relay.tls_check_peer = -1;
+#endif
+
+    /* Server defaults */
+    TAILQ_INIT(&config->server.addresses.addrs);
+    config->server.addresses.refcnt = 1;
+    config->server.timeout.tv_sec = DEFAULT_SOCKET_TIMEOUT_SEC;
+    config->server.tcp_keepalive = true;
+    config->server.log_type = SERVER_LOG_SYSLOG;
+    config->server.pid_file = strdup(_PATH_SUDO_LOGSRVD_PID);
+    if (config->server.pid_file == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	goto bad;
+    }
+
+#if defined(HAVE_OPENSSL)
+    /*
+     * Only set default CA and cert paths if the files actually exist.
+     * This ensures we don't enable TLS by default when it is not configured.
+     */
+    if (access(DEFAULT_CA_CERT_PATH, R_OK) == 0) {
+	config->server.tls_cacert_path = strdup(DEFAULT_CA_CERT_PATH);
+	if (config->server.tls_cacert_path == NULL) {
+	    sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	    goto bad;
+	}
+    }
+    if (access(DEFAULT_SERVER_CERT_PATH, R_OK) == 0) {
+	config->server.tls_cert_path = strdup(DEFAULT_SERVER_CERT_PATH);
+	if (config->server.tls_cert_path == NULL) {
+	    sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	    goto bad;
+	}
+    }
+    config->server.tls_key_path = strdup(DEFAULT_SERVER_KEY_PATH);
+    if (config->server.tls_key_path == NULL) {
+	sudo_warnx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
+	goto bad;
+    }
+    config->server.tls_verify = true;
+    config->server.tls_check_peer = false;
+#endif
+
+    /* I/O log defaults */
+    config->iolog.compress = false;
+    config->iolog.flush = true;
+    config->iolog.mode = S_IRUSR|S_IWUSR;
+    config->iolog.maxseq = SESSID_MAX;
+    if (!cb_iolog_dir(config, _PATH_SUDO_IO_LOGDIR, 0))
+	goto bad;
+    if (!cb_iolog_file(config, "%{seq}", 0))
+	goto bad;
+    config->iolog.uid = ROOT_UID;
+    config->iolog.gid = ROOT_GID;
+    config->iolog.gid_set = false;
+    config->iolog.log_passwords = true;
+
+    /* Event log defaults */
+    config->eventlog.log_type = EVLOG_SYSLOG;
+    config->eventlog.log_format = EVLOG_SUDO;
+    config->eventlog.log_exit = false;
+
+    /* Syslog defaults */
+    config->syslog.maxlen = 960;
+    config->syslog.server_facility = LOG_DAEMON;
+    if (!cb_syslog_facility(config, LOGFAC, 0)) {
+	sudo_warnx(U_("unknown syslog facility %s"), LOGFAC);
+	goto bad;
+    }
+    if (!cb_syslog_acceptpri(config, PRI_SUCCESS, 0)) {
+	sudo_warnx(U_("unknown syslog priority %s"), PRI_SUCCESS);
+	goto bad;
+    }
+    if (!cb_syslog_rejectpri(config, PRI_FAILURE, 0)) {
+	sudo_warnx(U_("unknown syslog priority %s"), PRI_FAILURE);
+	goto bad;
+    }
+    if (!cb_syslog_alertpri(config, PRI_FAILURE, 0)) {
+	sudo_warnx(U_("unknown syslog priority %s"), PRI_FAILURE);
+	goto bad;
+    }
+
+    /* Log file defaults */
+    if (!cb_logfile_time_format(config, "%h %e %T", 0))
+	goto bad;
+    if (!cb_logfile_path(config, _PATH_SUDO_LOGFILE, 0))
+	goto bad;
+
+    debug_return_ptr(config);
+bad:
+    logsrvd_conf_free(config);
+    debug_return_ptr(NULL);
+}
+
+static bool
+logsrvd_conf_apply(struct logsrvd_config *config)
+{
+#if defined(HAVE_OPENSSL)
+    struct server_address *addr;
+#endif
+    debug_decl(logsrvd_conf_apply, SUDO_DEBUG_UTIL);
+
+    /* There can be multiple passprompt regular expressions. */
+    if (config->iolog.passprompt_regex == NULL) {
+	if (!cb_iolog_passprompt_regex(config, PASSPROMPT_REGEX, 0))
+	    debug_return_bool(false);
+    }
+
+    /* There can be multiple addresses so we can't set a default earlier. */
+    if (TAILQ_EMPTY(&config->server.addresses.addrs)) {
+	/* Enable plaintext listender. */
+	if (!cb_server_listen_address(config, "*:" DEFAULT_PORT, 0))
+	    debug_return_bool(false);
+#if defined(HAVE_OPENSSL)
+	/* If a certificate was specified, enable the TLS listener too. */
+	if (config->server.tls_cert_path != NULL) {
+	    if (!cb_server_listen_address(config, "*:" DEFAULT_PORT_TLS "(tls)", 0))
+		debug_return_bool(false);
+	}
+    } else {
+	/* Check that TLS configuration is valid. */
+	TAILQ_FOREACH(addr, &config->server.addresses.addrs, entries) {
+	    if (!addr->tls)
+		continue;
+	    /*
+	     * If a TLS listener was explicitly enabled but the cert path
+	     * was not, use the default.
+	     */
+	    if (config->server.tls_cert_path == NULL) {
+		config->server.tls_cert_path =
+		    strdup(DEFAULT_SERVER_CERT_PATH);
+		if (config->server.tls_cert_path == NULL) {
+		    sudo_warnx(U_("%s: %s"), __func__,
+			U_("unable to allocate memory"));
+		    debug_return_bool(false);
+		}
+	    }
+	    break;
+	}
+#endif /* HAVE_OPENSSL */
+    }
+
+#if defined(HAVE_OPENSSL)
+    TAILQ_FOREACH(addr, &config->server.addresses.addrs, entries) {
+	if (!addr->tls)
+	    continue;
+        /* Create a TLS context for the server. */
+	config->server.ssl_ctx = init_tls_context(
+	    config->server.tls_cacert_path, config->server.tls_cert_path,
+	    config->server.tls_key_path, config->server.tls_dhparams_path,
+	    config->server.tls_ciphers_v12, config->server.tls_ciphers_v13,
+	    config->server.tls_verify);
+	if (config->server.ssl_ctx == NULL) {
+	    sudo_warnx("%s", U_("unable to initialize server TLS context"));
+	    debug_return_bool(false);
+	}
+	break;
+    }
+
+    if (TLS_CONFIGURED(config->relay)) {
+	TAILQ_FOREACH(addr, &config->relay.relays.addrs, entries) {
+	    if (!addr->tls)
+		continue;
+	    /* Create a TLS context for the relay. */
+	    config->relay.ssl_ctx = init_tls_context(
+		TLS_RELAY_STR(config, tls_cacert_path),
+		TLS_RELAY_STR(config, tls_cert_path),
+		TLS_RELAY_STR(config, tls_key_path),
+		TLS_RELAY_STR(config, tls_dhparams_path),
+		TLS_RELAY_STR(config, tls_ciphers_v12),
+		TLS_RELAY_STR(config, tls_ciphers_v13),
+		TLS_RELAY_INT(config, tls_verify));
+	    if (config->relay.ssl_ctx == NULL) {
+		sudo_warnx("%s", U_("unable to initialize relay TLS context"));
+		debug_return_bool(false);
+	    }
+	    break;
+	}
+    }
+#endif /* HAVE_OPENSSL */
+
+    /* Clear store_first if not relaying. */
+    if (TAILQ_EMPTY(&config->relay.relays.addrs))
+	config->relay.store_first = false;
+
+    /* Open server log if specified. */
+    switch (config->server.log_type) {
+    case SERVER_LOG_SYSLOG:
+	sudo_warn_set_conversation(logsrvd_conv_syslog);
+	break;
+    case SERVER_LOG_FILE:
+	config->server.log_stream =
+	    logsrvd_open_log_file(config->server.log_file, O_WRONLY|O_APPEND|O_CREAT);
+	if (config->server.log_stream == NULL)
+	    debug_return_bool(false);
+	sudo_warn_set_conversation(logsrvd_conv_logfile);
+	break;
+    case SERVER_LOG_NONE:
+	sudo_warn_set_conversation(logsrvd_conv_none);
+	break;
+    case SERVER_LOG_STDERR:
+	/* Default is stderr. */
+	sudo_warn_set_conversation(NULL);
+	break;
+    default:
+	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+	    "cannot open unknown log type %d", config->eventlog.log_type);
+	break;
+    }
+
+    /* Open event log if specified. */
+    switch (config->eventlog.log_type) {
+    case EVLOG_SYSLOG:
+	openlog("sudo", 0, config->syslog.facility);
+	break;
+    case EVLOG_FILE:
+	config->logfile.stream = logsrvd_open_eventlog(config);
+	if (config->logfile.stream == NULL)
+	    debug_return_bool(false);
+	break;
+    case EVLOG_NONE:
+	break;
+    default:
+	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+	    "cannot open unknown log type %d", config->eventlog.log_type);
+	break;
+    }
+
+    /*
+     * Update event and I/O log library config and install the new
+     * logsrvd config.  We must not fail past this point or the event
+     * and I/O log config will be inconsistent with the logsrvd config.
+     */
+    logsrvd_conf_iolog_setconf(config);
+    logsrvd_conf_eventlog_setconf(config);
+
+    logsrvd_conf_free(logsrvd_config);
+    logsrvd_config = config;
+
+    debug_return_bool(true);
+}
+
+/*
+ * Read .ini style logsrvd.conf file.
+ * Note that we use '#' not ';' for the comment character.
+ */
+bool
+logsrvd_conf_read(const char *path)
+{
+    struct logsrvd_config *config;
+    bool ret = false;
+    FILE *fp = NULL;
+    debug_decl(logsrvd_conf_read, SUDO_DEBUG_UTIL);
+
+    config = logsrvd_conf_alloc();
+
+    if ((fp = fopen(path, "r")) == NULL) {
+	if (errno != ENOENT) {
+	    sudo_warn("%s", path);
+	    goto done;
+	}
+    } else {
+	if (!logsrvd_conf_parse(config, fp, path))
+	    goto done;
+    }
+
+    /* Install new config */
+    if (logsrvd_conf_apply(config)) {
+	config = NULL;
+	ret = true;
+    }
+
+done:
+    logsrvd_conf_free(config);
+    if (fp != NULL)
+	fclose(fp);
+    debug_return_bool(ret);
+}
+
+void
+logsrvd_conf_cleanup(void)
+{
+    debug_decl(logsrvd_conf_cleanup, SUDO_DEBUG_UTIL);
+
+    logsrvd_conf_free(logsrvd_config);
+    logsrvd_config = NULL;
+
+    debug_return;
+}
+
+void
+logsrvd_warn_stderr(bool enabled)
+{
+    logsrvd_warn_enable_stderr = enabled;
+}