Complete redesign of this MPM. This is almost working now.

HOW IT WORKS:
    In the config file, the sysadmin specified:
         ChildPerUserID  uid gid num_processes
    and in each virtual host:
         AssignUserID  uid gid

    The MPM creates a unix domain socket for each uid/gid pair, and if any
    child processes are left over, one for the default user and group
    specified in the main config.

    When a child process is started, it looks at what it's user id and group
    id are supposed to be.  It then inserts the correct socket into it's
    listen array, and switches to the uid and gid specified.

    When a request comes in, whichever child gets the request looks at which
    child process it is actually for, and if it isn't for the current
    process, the request gets forwarded through the unix domain socket to the
    correct child process.  From there, processing continues normally.

    Currently, no requests are forwarded, but everything seems to be working.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@85971 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 152 insertions, 48 deletions

diff --git a/server/mpm/experimental/perchild/perchild.c b/server/mpm/experimental/perchild/perchild.c
index bca25653fa..a80df25936 100644
--- a/server/mpm/experimental/perchild/perchild.c
+++ b/server/mpm/experimental/perchild/perchild.c
@@ -108,6 +108,8 @@ static int max_requests_per_child = 0;
 static const char *ap_pid_fname=NULL;
 API_VAR_EXPORT const char *ap_scoreboard_fname=NULL;
 static int num_daemons=0;
+static int curr_child_num=0;
+static int socket_num=0;
 static int workers_may_exit = 0;
 static int requests_this_child;
 static int num_listenfds = 0;
@@ -116,11 +118,14 @@ static ap_socket_t **listenfds;
 struct child_info_t {
     uid_t uid;
     gid_t gid;
+    char *name;          /* The extention for this socket.  "uig:gid" */
+    int num;
+    int sd;
 };
 
 struct socket_info_t {
     const char *sname;   /* The servername */
-    int        cnum;     /* The child number */
+    int        cnum;     /* The socket number */
 };
 
 typedef struct {
@@ -772,9 +777,10 @@ static int create_child_socket(int child_num, ap_pool_t *p)
     int sd;
     perchild_server_conf *sconf = (perchild_server_conf *)
               ap_get_module_config(ap_server_conf->module_config, &mpm_perchild_module);
-    char *socket_name = ap_palloc(p, strlen(sconf->sockname) + 6);
+    int len = strlen(sconf->sockname) + strlen(child_info_table[child_num].name) + 3;
+    char *socket_name = ap_palloc(p, len);
 
-    ap_snprintf(socket_name, strlen(socket_name), "%s.%d", sconf->sockname, child_num);
+    ap_snprintf(socket_name, len, "%s.%s", sconf->sockname, child_info_table[child_num].name);
     if (unlink(socket_name) < 0 &&
         errno != ENOENT) {
         ap_log_error(APLOG_MARK, APLOG_ERR, errno, ap_server_conf,
@@ -843,9 +849,6 @@ static void child_main(int child_num_arg)
         clean_child_exit(APEXIT_CHILDFATAL);
     }
 
-    /* Add the sockets for this child process's virtual hosts */
-    sd = create_child_socket(child_num, pchild);
-
     if (perchild_setup_child(child_num)) {
 	clean_child_exit(APEXIT_CHILDFATAL);
     }
@@ -880,7 +883,10 @@ static void child_main(int child_num_arg)
 #if APR_FILES_AS_SOCKETS
     ap_socket_from_file(&listenfds[0], pipe_of_death_in);
 #endif
-    for (lr = ap_listeners, i = 1; i <= num_listenfds; lr = lr->next, ++i)
+    /* The child socket */
+    ap_put_os_sock(&listenfds[1], &sd, pchild);
+    num_listenfds++;
+    for (lr = ap_listeners, i = 2; i <= num_listenfds; lr = lr->next, ++i)
         listenfds[i]=lr->sd;
 
     /* Setup worker threads */
@@ -1175,6 +1181,27 @@ int ap_mpm_run(ap_pool_t *_pconf, ap_pool_t *plog, server_rec *s)
     }
     ap_log_pid(pconf, ap_pid_fname);
 
+    /* Create all of the sockets for the child processes. */
+    for (i = 0; i <= socket_num; i++) {
+        int sd;
+        int j;
+
+        sd = create_child_socket(i, pchild);
+       
+        for(j = i; ;) {
+            if (child_info_table[j].num == i) {
+                child_info_table[j].sd = sd;
+                j++;
+            }
+            else {
+                break;
+            }
+        }
+        if (j >= num_daemons) { 
+            break;
+        }
+    } 
+
     /* Initialize cross-process accept lock */
     lock_fname = ap_psprintf(_pconf, "%s.%u",
                              ap_server_root_relative(_pconf, lock_fname),
@@ -1306,15 +1333,17 @@ int ap_mpm_run(ap_pool_t *_pconf, ap_pool_t *plog, server_rec *s)
 static void perchild_pre_config(ap_pool_t *p, ap_pool_t *plog, ap_pool_t *ptemp)
 {
     static int restart_num = 0;
+    int no_detach = 0;
     int i;
 
     one_process = !!getenv("ONE_PROCESS");
+    no_detach = !!getenv("NO_DETACH");
 
     /* sigh, want this only the second time around */
     if (restart_num++ == 1) {
 	is_graceful = 0;
 
-	if (!one_process) {
+	if (!one_process && !no_detach) {
 	    ap_detach();
 	}
 
@@ -1333,12 +1362,28 @@ static void perchild_pre_config(ap_pool_t *p, ap_pool_t *plog, ap_pool_t *ptemp)
     lock_fname = DEFAULT_LOCKFILE;
     max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
     ap_perchild_set_maintain_connection_status(1);
+    curr_child_num = 0;
+    socket_num = 0;
 
     ap_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
 
     for (i = 0; i < HARD_SERVER_LIMIT; i++) {
         child_info_table[i].uid = -1;
         child_info_table[i].gid = -1;
+        child_info_table[i].name = NULL;
+        child_info_table[i].num = -1;
+    }
+}
+
+static void perchild_post_config(ap_pool_t *p, ap_pool_t *plog, ap_pool_t *ptemp, server_rec *s)
+{
+    int i;
+
+    for (i = 0; i < num_daemons; i++) {
+        if (child_info_table[i].name == NULL) {
+            child_info_table[i].name = ap_pstrdup(p, "DEFAULT");
+            child_info_table[i].num = socket_num;
+        }
     }
 }
 
@@ -1362,7 +1407,6 @@ fprintf(stderr, "In perchild_post_read\n");
 fprintf(stderr, "leaving DECLINED\n");
         return DECLINED;
     }
-fprintf(stderr, "leaving OK\n");
     return OK;
 }
 
@@ -1372,6 +1416,7 @@ static void perchild_hooks(void)
     one_process = 0;
 
     ap_hook_pre_config(perchild_pre_config, NULL, NULL, AP_HOOK_MIDDLE); 
+    ap_hook_post_config(perchild_post_config, NULL, NULL, AP_HOOK_MIDDLE); 
     /* This must be run absolutely first.  If this request isn't for this
      * server then we need to forward it to the proper child.  No sense
      * tying up this server running more post_read request hooks if it is
@@ -1571,20 +1616,25 @@ static const char *set_coredumpdir (cmd_parms *cmd, void *dummy, const char *arg
     return NULL;
 }
 
-static const char *set_childprocess(cmd_parms *cmd, void *dummy, const char *p,
-                                    const char *u, const char *g) 
+static const char *set_child_per_uid(cmd_parms *cmd, void *dummy, const char *u,
+                                     const char *g, const char *num)
 {
-    int curr_child_num = atoi(p);
-    child_info_t *ug = &child_info_table[curr_child_num - 1];
+    int i;
+    int max_this_time = atoi(num) + curr_child_num;
+    for (i = curr_child_num; i < max_this_time; i++, curr_child_num++); {
+        child_info_t *ug = &child_info_table[i - 1];
 
-    if (curr_child_num > num_daemons) {
-        return "Trying to use more child ID's than NumServers.  Increase "
-               "NumServers in your config file.";
+        if (i > num_daemons) {
+            return "Trying to use more child ID's than NumServers.  Increase "
+                   "NumServers in your config file.";
+        }
+    
+        ug->uid = atoi(u);
+        ug->gid = atoi(g); 
+        ug->name = ap_pstrcat(cmd->pool, u, ":", g, NULL);
+        ug->num = socket_num;
     }
-   
-    ug->uid = atoi(u);
-    ug->gid = atoi(g); 
-
+    socket_num++;
     return NULL;
 }
 
@@ -1604,13 +1654,15 @@ static ap_status_t cleanup_hash(void *dptr)
     return APR_SUCCESS;
 }
 
-static const char *assign_childprocess(cmd_parms *cmd, void *dummy, const char *p)
+static const char *assign_childuid(cmd_parms *cmd, void *dummy, const char *uid,
+                                   const char *gid)
 {
+    char *socketname = ap_pstrcat(cmd->pool, uid, ":", gid, NULL);
     if (socket_info_table == NULL) {
         socket_info_table = ap_make_hash(cmd->pool);
         ap_register_cleanup(cmd->pool, socket_info_table, cleanup_hash, NULL);
     }
-    ap_hash_set(socket_info_table, cmd->server->server_hostname, 0, p);
+    ap_hash_set(socket_info_table, cmd->server->server_hostname, 0, socketname);
     return NULL;
 }
 
@@ -1640,9 +1692,9 @@ AP_INIT_FLAG("ConnectionStatus", set_maintain_connection_status, NULL, RSRC_CONF
              "Whether or not to maintain status information on current connections"),
 AP_INIT_TAKE1("CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF,
               "The location of the directory Apache changes to before dumping core"),
-AP_INIT_TAKE3("ChildProcess", set_childprocess, NULL, RSRC_CONF,
+AP_INIT_TAKE3("ChildperUserID", set_child_per_uid, NULL, RSRC_CONF,
               "Specify a User and Group for a specific child process."),
-AP_INIT_TAKE1("AssignChild", assign_childprocess, NULL, RSRC_CONF,
+AP_INIT_TAKE2("AssignUserID", assign_childuid, NULL, RSRC_CONF,
               "Tie a virtual host to a specific child process."),
 AP_INIT_TAKE1("ChildSockName", set_socket_name, NULL, RSRC_CONF,
               "the base name of the socket to use for communication between "
diff --git a/server/mpm/perchild/perchild.c b/server/mpm/perchild/perchild.c
index bca25653fa..a80df25936 100644
--- a/server/mpm/perchild/perchild.c
+++ b/server/mpm/perchild/perchild.c
@@ -108,6 +108,8 @@ static int max_requests_per_child = 0;
 static const char *ap_pid_fname=NULL;
 API_VAR_EXPORT const char *ap_scoreboard_fname=NULL;
 static int num_daemons=0;
+static int curr_child_num=0;
+static int socket_num=0;
 static int workers_may_exit = 0;
 static int requests_this_child;
 static int num_listenfds = 0;
@@ -116,11 +118,14 @@ static ap_socket_t **listenfds;
 struct child_info_t {
     uid_t uid;
     gid_t gid;
+    char *name;          /* The extention for this socket.  "uig:gid" */
+    int num;
+    int sd;
 };
 
 struct socket_info_t {
     const char *sname;   /* The servername */
-    int        cnum;     /* The child number */
+    int        cnum;     /* The socket number */
 };
 
 typedef struct {
@@ -772,9 +777,10 @@ static int create_child_socket(int child_num, ap_pool_t *p)
     int sd;
     perchild_server_conf *sconf = (perchild_server_conf *)
               ap_get_module_config(ap_server_conf->module_config, &mpm_perchild_module);
-    char *socket_name = ap_palloc(p, strlen(sconf->sockname) + 6);
+    int len = strlen(sconf->sockname) + strlen(child_info_table[child_num].name) + 3;
+    char *socket_name = ap_palloc(p, len);
 
-    ap_snprintf(socket_name, strlen(socket_name), "%s.%d", sconf->sockname, child_num);
+    ap_snprintf(socket_name, len, "%s.%s", sconf->sockname, child_info_table[child_num].name);
     if (unlink(socket_name) < 0 &&
         errno != ENOENT) {
         ap_log_error(APLOG_MARK, APLOG_ERR, errno, ap_server_conf,
@@ -843,9 +849,6 @@ static void child_main(int child_num_arg)
         clean_child_exit(APEXIT_CHILDFATAL);
     }
 
-    /* Add the sockets for this child process's virtual hosts */
-    sd = create_child_socket(child_num, pchild);
-
     if (perchild_setup_child(child_num)) {
 	clean_child_exit(APEXIT_CHILDFATAL);
     }
@@ -880,7 +883,10 @@ static void child_main(int child_num_arg)
 #if APR_FILES_AS_SOCKETS
     ap_socket_from_file(&listenfds[0], pipe_of_death_in);
 #endif
-    for (lr = ap_listeners, i = 1; i <= num_listenfds; lr = lr->next, ++i)
+    /* The child socket */
+    ap_put_os_sock(&listenfds[1], &sd, pchild);
+    num_listenfds++;
+    for (lr = ap_listeners, i = 2; i <= num_listenfds; lr = lr->next, ++i)
         listenfds[i]=lr->sd;
 
     /* Setup worker threads */
@@ -1175,6 +1181,27 @@ int ap_mpm_run(ap_pool_t *_pconf, ap_pool_t *plog, server_rec *s)
     }
     ap_log_pid(pconf, ap_pid_fname);
 
+    /* Create all of the sockets for the child processes. */
+    for (i = 0; i <= socket_num; i++) {
+        int sd;
+        int j;
+
+        sd = create_child_socket(i, pchild);
+       
+        for(j = i; ;) {
+            if (child_info_table[j].num == i) {
+                child_info_table[j].sd = sd;
+                j++;
+            }
+            else {
+                break;
+            }
+        }
+        if (j >= num_daemons) { 
+            break;
+        }
+    } 
+
     /* Initialize cross-process accept lock */
     lock_fname = ap_psprintf(_pconf, "%s.%u",
                              ap_server_root_relative(_pconf, lock_fname),
@@ -1306,15 +1333,17 @@ int ap_mpm_run(ap_pool_t *_pconf, ap_pool_t *plog, server_rec *s)
 static void perchild_pre_config(ap_pool_t *p, ap_pool_t *plog, ap_pool_t *ptemp)
 {
     static int restart_num = 0;
+    int no_detach = 0;
     int i;
 
     one_process = !!getenv("ONE_PROCESS");
+    no_detach = !!getenv("NO_DETACH");
 
     /* sigh, want this only the second time around */
     if (restart_num++ == 1) {
 	is_graceful = 0;
 
-	if (!one_process) {
+	if (!one_process && !no_detach) {
 	    ap_detach();
 	}
 
@@ -1333,12 +1362,28 @@ static void perchild_pre_config(ap_pool_t *p, ap_pool_t *plog, ap_pool_t *ptemp)
     lock_fname = DEFAULT_LOCKFILE;
     max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
     ap_perchild_set_maintain_connection_status(1);
+    curr_child_num = 0;
+    socket_num = 0;
 
     ap_cpystrn(ap_coredump_dir, ap_server_root, sizeof(ap_coredump_dir));
 
     for (i = 0; i < HARD_SERVER_LIMIT; i++) {
         child_info_table[i].uid = -1;
         child_info_table[i].gid = -1;
+        child_info_table[i].name = NULL;
+        child_info_table[i].num = -1;
+    }
+}
+
+static void perchild_post_config(ap_pool_t *p, ap_pool_t *plog, ap_pool_t *ptemp, server_rec *s)
+{
+    int i;
+
+    for (i = 0; i < num_daemons; i++) {
+        if (child_info_table[i].name == NULL) {
+            child_info_table[i].name = ap_pstrdup(p, "DEFAULT");
+            child_info_table[i].num = socket_num;
+        }
     }
 }
 
@@ -1362,7 +1407,6 @@ fprintf(stderr, "In perchild_post_read\n");
 fprintf(stderr, "leaving DECLINED\n");
         return DECLINED;
     }
-fprintf(stderr, "leaving OK\n");
     return OK;
 }
 
@@ -1372,6 +1416,7 @@ static void perchild_hooks(void)
     one_process = 0;
 
     ap_hook_pre_config(perchild_pre_config, NULL, NULL, AP_HOOK_MIDDLE); 
+    ap_hook_post_config(perchild_post_config, NULL, NULL, AP_HOOK_MIDDLE); 
     /* This must be run absolutely first.  If this request isn't for this
      * server then we need to forward it to the proper child.  No sense
      * tying up this server running more post_read request hooks if it is
@@ -1571,20 +1616,25 @@ static const char *set_coredumpdir (cmd_parms *cmd, void *dummy, const char *arg
     return NULL;
 }
 
-static const char *set_childprocess(cmd_parms *cmd, void *dummy, const char *p,
-                                    const char *u, const char *g) 
+static const char *set_child_per_uid(cmd_parms *cmd, void *dummy, const char *u,
+                                     const char *g, const char *num)
 {
-    int curr_child_num = atoi(p);
-    child_info_t *ug = &child_info_table[curr_child_num - 1];
+    int i;
+    int max_this_time = atoi(num) + curr_child_num;
+    for (i = curr_child_num; i < max_this_time; i++, curr_child_num++); {
+        child_info_t *ug = &child_info_table[i - 1];
 
-    if (curr_child_num > num_daemons) {
-        return "Trying to use more child ID's than NumServers.  Increase "
-               "NumServers in your config file.";
+        if (i > num_daemons) {
+            return "Trying to use more child ID's than NumServers.  Increase "
+                   "NumServers in your config file.";
+        }
+    
+        ug->uid = atoi(u);
+        ug->gid = atoi(g); 
+        ug->name = ap_pstrcat(cmd->pool, u, ":", g, NULL);
+        ug->num = socket_num;
     }
-   
-    ug->uid = atoi(u);
-    ug->gid = atoi(g); 
-
+    socket_num++;
     return NULL;
 }
 
@@ -1604,13 +1654,15 @@ static ap_status_t cleanup_hash(void *dptr)
     return APR_SUCCESS;
 }
 
-static const char *assign_childprocess(cmd_parms *cmd, void *dummy, const char *p)
+static const char *assign_childuid(cmd_parms *cmd, void *dummy, const char *uid,
+                                   const char *gid)
 {
+    char *socketname = ap_pstrcat(cmd->pool, uid, ":", gid, NULL);
     if (socket_info_table == NULL) {
         socket_info_table = ap_make_hash(cmd->pool);
         ap_register_cleanup(cmd->pool, socket_info_table, cleanup_hash, NULL);
     }
-    ap_hash_set(socket_info_table, cmd->server->server_hostname, 0, p);
+    ap_hash_set(socket_info_table, cmd->server->server_hostname, 0, socketname);
     return NULL;
 }
 
@@ -1640,9 +1692,9 @@ AP_INIT_FLAG("ConnectionStatus", set_maintain_connection_status, NULL, RSRC_CONF
              "Whether or not to maintain status information on current connections"),
 AP_INIT_TAKE1("CoreDumpDirectory", set_coredumpdir, NULL, RSRC_CONF,
               "The location of the directory Apache changes to before dumping core"),
-AP_INIT_TAKE3("ChildProcess", set_childprocess, NULL, RSRC_CONF,
+AP_INIT_TAKE3("ChildperUserID", set_child_per_uid, NULL, RSRC_CONF,
               "Specify a User and Group for a specific child process."),
-AP_INIT_TAKE1("AssignChild", assign_childprocess, NULL, RSRC_CONF,
+AP_INIT_TAKE2("AssignUserID", assign_childuid, NULL, RSRC_CONF,
               "Tie a virtual host to a specific child process."),
 AP_INIT_TAKE1("ChildSockName", set_socket_name, NULL, RSRC_CONF,
               "the base name of the socket to use for communication between "