add `user` config option

doc/shadowsocks-libev.asciidoc

@@ -165,6 +165,7 @@ The config file equivalent of command line options is listed as example below.
 | -k "PasSworD"                       | "password": "PasSworD"
 | -m "aes-256-cfb"                    | "method": "aes-256-cfb"
 | -t 60                               | "timeout": 60
+| -a nobody                           | "user": "nobody"
 | --fast-open                         | "fast_open": true
 | -6                                  | "ipv6_first": true
 | -A                                  | "auth": true

src/jconf.c

@@ -197,6 +197,8 @@ read_jconf(const char *file)
                 conf.method = to_string(value);
             } else if (strcmp(name, "timeout") == 0) {
                 conf.timeout = to_string(value);
+            } else if (strcmp(name, "user") == 0) {
+                conf.user = to_string(value);
             } else if (strcmp(name, "fast_open") == 0) {
                 check_json_value_type(value, json_boolean,
                         "invalid config file: option 'fast_open' must be a boolean");

src/jconf.h

@@ -55,6 +55,7 @@ typedef struct {
     char *password;
     char *method;
     char *timeout;
+    char *user;
     int auth;
     int fast_open;
     int nofile;

src/local.c

@@ -1291,6 +1291,9 @@ main(int argc, char **argv)
         if (timeout == NULL) {
             timeout = conf->timeout;
         }
+        if (user == NULL) {
+            user = conf->user;
+        }
         if (auth == 0) {
             auth = conf->auth;
         }

src/manager.c

@@ -744,6 +744,9 @@ main(int argc, char **argv)
         if (timeout == NULL) {
             timeout = conf->timeout;
         }
+        if (user == NULL) {
+            user = conf->user;
+        }
 #ifdef TCP_FASTOPEN
         if (fast_open == 0) {
             fast_open = conf->fast_open;

src/redir.c

@@ -898,6 +898,9 @@ main(int argc, char **argv)
         if (timeout == NULL) {
             timeout = conf->timeout;
         }
+        if (user == NULL) {
+            user = conf->user;
+        }
         if (auth == 0) {
             auth = conf->auth;
         }

src/server.c

@@ -1699,6 +1699,9 @@ main(int argc, char **argv)
         if (timeout == NULL) {
             timeout = conf->timeout;
         }
+        if (user == NULL) {
+            user = conf->user;
+        }
         if (auth == 0) {
             auth = conf->auth;
         }

src/tunnel.c

@@ -885,6 +885,9 @@ main(int argc, char **argv)
         if (timeout == NULL) {
             timeout = conf->timeout;
         }
+        if (user == NULL) {
+            user = conf->user;
+        }
         if (auth == 0) {
             auth = conf->auth;
         }