diff options
Diffstat (limited to 'node.c')
| -rw-r--r-- | node.c | 511 |
1 files changed, 393 insertions, 118 deletions
@@ -5,7 +5,7 @@ /*----------------------------------------------------------------------------*/ /*Based on the code of unionfs translator.*/ /*----------------------------------------------------------------------------*/ -/*Copyright (C) 2001, 2002, 2005 Free Software Foundation, Inc. +/*Copyright (C) 2001, 2002, 2005, 2008 Free Software Foundation, Inc. Written by Sergiu Ivanov <unlimitedscolobb@gmail.com>. This program is free software; you can redistribute it and/or @@ -33,6 +33,12 @@ #include <sys/mman.h> #include <stdio.h> #include <argz.h> +#include <hurd/fsys.h> + + +/*!!!!!!!REMOVE THIS!!!!!!*/ +#include <sys/file.h> + /*----------------------------------------------------------------------------*/ #include "debug.h" #include "node.h" @@ -63,6 +69,9 @@ node_create /*Create a new netnode*/ netnode_t * netnode_new = malloc(sizeof(netnode_t)); + /*Reset the memory allocated for the new netnode (just in case :-) )*/ + memset(netnode_new, 0, sizeof(netnode_t)); + /*If the memory could not be allocated*/ if(netnode_new == NULL) err = ENOMEM; @@ -86,12 +95,18 @@ node_create /*link the lnode to the new node*/ lnode->node = node_new; - lnode_ref_add(lnode); - + /*setup the references in the newly created node*/ node_new->nn->lnode = lnode; + lnode_ref_add(lnode); + + /*setup the information in the netnode*/ node_new->nn->flags = 0; node_new->nn->ncache_next = node_new->nn->ncache_prev = NULL; + + /*initialize the list of translators*/ + node_new->nn->trans = NULL; + node_new->nn->ntrans = node_new->nn->translen = 0; /*store the result of creation in the second parameter*/ *node = node_new; @@ -101,6 +116,64 @@ node_create return err; }/*node_create*/ /*----------------------------------------------------------------------------*/ +/*Derives a new proxy from `lnode`*/ +error_t +node_create_proxy + ( + lnode_t * lnode, + node_t ** node /*store the result here*/ + ) + { + error_t err = 0; + + /*Create a new netnode*/ + netnode_t * netnode_new = malloc(sizeof(netnode_t)); + + /*Reset the memory allocated for the new netnode. We do this here + since lnode_add_proxy will try to reference the `lnode` in this netnode + and will do bad writes to memory.*/ + memset(netnode_new, 0, sizeof(netnode_t)); + + /*If the memory could not be allocated*/ + if(netnode_new == NULL) + err = ENOMEM; + else + { + /*create a new node from the netnode*/ + node_t * node_new = netfs_make_node(netnode_new); + + /*If the creation failed*/ + if(node_new == NULL) + { + /*set the error code*/ + err = ENOMEM; + + /*destroy the netnode created above*/ + free(netnode_new); + + /*stop*/ + return err; + } + + /*add this new node to the list of proxies of `lnode`*/ + lnode_add_proxy(lnode, node_new); + + /*setup the information in the netnode*/ + node_new->nn->flags = 0; + node_new->nn->ncache_next = node_new->nn->ncache_prev = NULL; + + /*initialize the list of translators*/ + node_new->nn->trans = NULL; + node_new->nn->ntrans = node_new->nn->translen = 0; + + /*store the result of creation in the second parameter*/ + *node = node_new; + } + + /*Return the result of operations*/ + return err; + }/*node_create_proxy*/ +/*----------------------------------------------------------------------------*/ /*Destroys the specified node and removes a light reference from the associated light node*/ void @@ -116,19 +189,23 @@ node_destroy if(np->nn->port != MACH_PORT_NULL) PORT_DEALLOC(np->nn->port); - /*If the given node is not the root node and there are translators - to kill*/ - if(np->nn->lnode->dir && np->nn->lnode->trans) + /*If there are translators to kill*/ + if(np->nn->lnode->dir && np->nn->trans) { /*kill all translators on the underlying nodes*/ - node_kill_all_translators(np); + node_kill_translators(np); } /*Lock the lnode corresponding to the current node*/ mutex_lock(&np->nn->lnode->lock); - /*Orphan the light node*/ - np->nn->lnode->node = NULL; + /*If the node to be destroyed is a real netfs node*/ + if(np->nn->lnode->node == np) + /*orphan the light node*/ + np->nn->lnode->node = NULL; + else + /*remove a reference to this node from the list of proxies*/ + lnode_remove_proxy(np->nn->lnode, np); /*Remove a reference from the lnode*/ lnode_ref_remove(np->nn->lnode); @@ -632,22 +709,24 @@ node_unlink_file return err; }/*node_unlink_file*/ /*----------------------------------------------------------------------------*/ -/*Sets the given translator on the supplied node*/ -/*This function will normally be called from netfs_attempt_lookup, therefore - it's better that the caller should provide the parent node for `node`.*/ +/*Sets the given translators on the specified node*/ error_t -node_set_translator +node_set_translators ( - node_t * dir, - node_t * node, - const char * trans /*set this on `name`*/ + struct protid * diruser, + node_t * np, + char * trans, /*set these on `node`*/ + size_t ntrans, + int flags, + mach_port_t * port ) { error_t err; - - /*A port for opened to the file*/ mach_port_t p; - + + /*An unauthenticated port to the directory containing `np`*/ + mach_port_t unauth_dir; + /*A copy (possibly extended) of the name of the translator*/ char * ext; @@ -655,10 +734,62 @@ node_set_translator char * argz = NULL; size_t argz_len = 0; + /*The pointer to the name of the translator we are going to start now*/ + char * str; + + /*The index of the translator in the list of strings*/ + size_t idx; + /*The control port for the active translator*/ mach_port_t active_control; + + /*A new element in the list of control ports*/ + port_el_t * p_el; + + /*A copy of the user information, supplied in `user`*/ + struct iouser * user; + + /*A protid for the supplied node*/ + struct protid * newpi; - /*Opens a port to the file at the request of fshelp_start_translator*/ + /*Identity information about the current process (for fsys_getroot)*/ + uid_t * uids; + size_t nuids; + + gid_t * gids; + size_t ngids; + + /*The retry information returned by fsys_getroot*/ + string_t retry_name; + mach_port_t retry_port; + + /*Try to get the number of effective UIDs*/ + nuids = geteuids(0, 0); + if(nuids < 0) + return EPERM; + + /*Allocate some memory for the UIDs on the stack*/ + uids = alloca(nuids * sizeof(uid_t)); + + /*Fetch the UIDs themselves*/ + nuids = geteuids(nuids, uids); + if(nuids < 0) + return EPERM; + + /*Try to get the number of effective GIDs*/ + ngids = getgroups(0, 0); + if(ngids < 0) + return EPERM; + + /*Allocate some memory for the GIDs on the stack*/ + gids = alloca(ngids * sizeof(gid_t)); + + /*Fetch the GIDs themselves*/ + ngids = getgroups(ngids, gids); + if(ngids < 0) + return EPERM; + + /*Opens the port on which to set the new translator*/ error_t open_port ( @@ -666,21 +797,58 @@ node_set_translator mach_port_t * underlying, mach_msg_type_name_t * underlying_type, task_t task, - void * cookie /*some additional information, not used here*/ + void * cookie /*if 0, open the port to the node; otherwise get the port + of the topmost translator on the node*/ ) { - /*Lookup the file we are working with*/ - p = file_name_lookup_under - (dir->nn->port, node->nn->lnode->name, flags, 0); - if(p == MACH_PORT_NULL) - return errno; + /*No errors at first*/ + err = 0; + + /*If a port to the node is wanted*/ + if((int)cookie == 0) + { + /*check, whether the user has the permissions to open this node*/ + err = check_open_permissions(diruser->user, &np->nn_stat, flags); + if(err) + return err; + + /*duplicate the supplied user*/ + err = iohelp_dup_iouser(&user, diruser->user); + if(err) + return err; + + /*create a protid for this node*/ + newpi = netfs_make_protid + (netfs_make_peropen(np, flags, diruser->po), user); + if(!newpi) + { + iohelp_free_iouser(user); + return errno; + } + LOG_MSG("node_set_translators.open_port: PASSED"); + + /*obtain the resulting port right and set its type appropriately*/ + *underlying = p = ports_get_send_right(newpi); + *underlying_type = MACH_MSG_TYPE_COPY_SEND; - /*Store the result in the parameters*/ - *underlying = p; - *underlying_type = MACH_MSG_TYPE_COPY_SEND; - - /*Here everything is OK*/ - return 0; + LOG_MSG("node_set_translators.open_port: %ld", (long)*underlying); + + /*drop our reference to the port*/ + ports_port_deref(newpi); + } + /*We are not setting the first translator, this one is not required + to sit on the node itself*/ + else + /*in the previous iteration of the loop fsys_getroot gave us the port + to the toplevel translator on the current node, namely `p`; this is + what is required of us now*/ + { + *underlying = p; + *underlying_type = MACH_MSG_TYPE_COPY_SEND; + } + + /*Return the result of operations (everything should be okay here)*/ + return err; }/*open_port*/ /*Adds a "/hurd/" at the beginning of the translator name, if required*/ @@ -715,47 +883,83 @@ node_set_translator return full; }/*put_in_hurd*/ - /*Obtain a copy (possibly extended) of the name*/ - ext = put_in_hurd(trans); - if(!ext) - return ENOMEM; - - /*TODO: Better argument-parsing?*/ - - /*Obtain the argz version of str*/ - err = argz_create_sep(ext, ' ', &argz, &argz_len); + /*Obtain the unauthenticated port to the directory*/ + err = io_restrict_auth(diruser->po->np->nn->port, &unauth_dir, 0, 0, 0, 0); if(err) return err; + + /*While all translators have not been looked through*/ + for(str = trans, idx = 0; idx < ntrans; ++idx) + { + /*obtain a copy (possibly extended) of the name*/ + ext = put_in_hurd(str); + if(!ext) + return ENOMEM; - /*Start the translator*/ - err = fshelp_start_translator - ( - open_port, NULL, argz, argz, argz_len, - 60000,/*this is the default in settrans*/ - &active_control - ); - if(err) - return err; + /*TODO: Better argument-parsing?*/ - /*Attempt to set a translator on the port opened by the previous call*/ - err = file_set_translator - ( - p, 0, FS_TRANS_SET, 0, argz, argz_len, - active_control, MACH_MSG_TYPE_COPY_SEND - ); - if(err) - return err; + /*obtain the argz version of str*/ + err = argz_create_sep(ext, ' ', &argz, &argz_len); + if(err) + return err; - /*Deallocate the port we have just opened*/ - PORT_DEALLOC(p); + /*start the translator*/ + err = fshelp_start_translator + ( + open_port, (void *)((idx == 0) ? 0 : 1), argz, argz, argz_len, + 60000,/*this is the default in settrans*/ + &active_control + ); + if(err) + return err; + + /*attempt to set a translator on the port opened by the previous call*/ + err = file_set_translator + ( + p, 0, FS_TRANS_SET, 0, argz, argz_len, + active_control, MACH_MSG_TYPE_COPY_SEND + ); + /*close the port we have just opened*/ + PORT_DEALLOC(p); + + /*stop, if the attempt to set the translator failed*/ + if(err) + return err; + + /*allocate a new element for the current control port*/ + p_el = malloc(sizeof(struct port_el)); + if(!p_el) + return ENOMEM; + + /*store the current control port in the new cell*/ + p_el->p = active_control; + + /*add the new control port to the list*/ + p_el->next = np->nn->cntl_ports; + np->nn->cntl_ports = p_el; + + /*obtain the port to the top of the newly-set translator*/ + err = fsys_getroot + ( + active_control, unauth_dir, MACH_MSG_TYPE_COPY_SEND, + uids, nuids, gids, ngids, + flags, &retry_port, retry_name, &p + ); + if(err) + return err; + } + + /*Return the port*/ + *port = p; /*Everything is OK here*/ return 0; - }/*node_set_translator*/ + }/*node_set_translators*/ /*----------------------------------------------------------------------------*/ /*Kill the topmost translator for this node*/ /*This function will normally be called from netfs_attempt_lookup, therefore it's better that the caller should provide the parent node for `node`.*/ +/*This is the code for the wrong version of nsmux.*/ error_t node_kill_translator ( @@ -763,88 +967,159 @@ node_kill_translator node_t * node ) { + error_t err = 0; + /*Lookup the file*/ mach_port_t p = - file_name_lookup_under(dir->nn->port, node->nn->lnode->name, O_NOTRANS, 0); + file_name_lookup_under + (dir->nn->port, node->nn->lnode->name, /*O_NOTRANS*/0, 0); + if(!p) + return errno; /*Remove a translator from the node*/ - error_t err = file_set_translator +/*This code was taken from the code of settrans and works only when there is + only one translator in the stack (not including the ext2fs, for example). + For this code to work the O_NOTRANS is required in the lookup.*/ + /*error_t err = file_set_translator ( p, FS_TRANS_SET, FS_TRANS_SET, 0, NULL, 0, MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND - ); + );*/ + + /*Obtain the control port of the filesystem to which file `name` belongs*/ + fsys_t fsys; + err = file_getcontrol(p, &fsys); + + char * argz = NULL; + size_t argz_len = 0; + err = file_get_fs_options(p, &argz, &argz_len); /*Close the port*/ PORT_DEALLOC(p); + /*If the control port of the filesystem could not be fetched, stop*/ + if(err) + return err; + + /*Ask the translator to go away*/ + err = fsys_goaway(fsys, 0); + + /*If the translator is busy*/ + if(err) + /*force the translator to go away*/ + err = fsys_goaway(fsys, FSYS_GOAWAY_FORCE); + + /*Deallocate the control port*/ + PORT_DEALLOC(fsys); + /*Return the result of removing the translator*/ return err; }/*node_kill_translator*/ /*----------------------------------------------------------------------------*/ /*Kills all translators on the nodes belonging to the given directory*/ void -node_kill_all_translators +node_kill_translators ( node_t * node ) { - /*Goes through all children of the given node recursively*/ - void - traverse_children_r - ( - node_t * dir, - node_t * np, - size_t ntrans /*the number of translators to remove from all nodes*/ - ) - { - int i; + /*If the node has no translators*/ + if(node->nn->trans == NULL) + /*nothing to do*/ + return; - /*A child of the current node*/ - lnode_t * ln = np->nn->lnode; - - /*If the current node is not a directory*/ - if(!(ln->flags & FLAG_LNODE_DIR)) - { - /*remove the required number of translators from the current node*/ - for(i = 0; i < ntrans + ln->ntrans; ++i) - node_kill_translator(dir, np); - } - else - /*Go through the list of entries belonging to this directory*/ - for(ln = ln->entries; ln; ln = ln->next) - { - /*die, if there is no node corresponding to the current child*/ - /*This is abnormal, because lnodes should normally go away shortly - after the destruction of correpsonding nodes*/ - assert(ln->node); - - /*kill translators for this node*/ - traverse_children_r(np, ln->node, ntrans + ln->ntrans); - } - - /*Obtain a pointer to the lnode corresponding to np*/ - ln = np->nn->lnode; + error_t err = 0; + + /*The current element in the port list*/ + port_el_t * p_el; + + /*While the list of control ports is not empty*/ + for(p_el = node->nn->cntl_ports; p_el; p_el = node->nn->cntl_ports) + { + /*kill the current translator*/ + err = fsys_goaway(p_el->p, 0); - /*Destroy the list of translators*/ - if(ln->trans) - free(ln->trans); + /*If the translator says it is busy, force it to go away*/ + if(err == EBUSY) + err = fsys_goaway(p_el->p, FSYS_GOAWAY_FORCE); - /*No more translators on this node*/ - ln->trans = NULL; - ln->ntrans = ln->translen = 0; + /*move the beginning of the list of control ports forward*/ + node->nn->cntl_ports = p_el->next; - /*There are no translators on this node*/ - ln->flags &= ~FLAG_LNODE_TRANSLATED; - }/*traverse_children_r*/ - - /*Obtain the pointer to the parent node of the current node*/ - node_t * dnp; - ncache_node_lookup(node->nn->lnode->dir, &dnp); + /*destroy the current cell in the list of ports*/ + free(p_el); + } + }/*node_kill_translators*/ +/*----------------------------------------------------------------------------*/ +/*Constructs a list of translators that were set on the ancestors of `node`*/ +/*TODO: Remove node_list_translators.*/ +error_t +node_list_translators + ( + node_t * node, + char ** trans, /*the malloced list of 0-separated strings*/ + size_t * ntrans /*the number of elements in `trans`*/ + ) + { + /*The size of block of memory for the list of translators*/ + size_t sz = 0; + + /*Used for tracing the lineage of `node`*/ + lnode_t * ln = node->nn->lnode; + + /*Used in computing the lengths of lists of translators in every node + we will go through and for constructing the final list of translators*/ + char * p; - /*Kill all translators on the current node*/ - traverse_children_r(dnp, node, node->nn->lnode->ntrans); + /*The current position in *data (used in filling out the list of + translators)*/ + char * transp; + + /*The length of the current translator name*/ + size_t complen; + + size_t i; + + /*Trace the lineage of the `node` (including itself) and compute the + total length of the list of translators*/ + for(; ln; sz += node->nn->translen, ln = ln->dir); + + /*Try to allocate a block of memory sufficient for storing the list of + translators*/ + *trans = malloc(sz); + if(!*trans) + return ENOMEM; - /*Unlock the parent node*/ - mutex_unlock(&dnp->lock); - }/*node_kill_all_translators*/ + /*No translators at first*/ + *ntrans = 0; + + /*Again trace the lineage of the `node` (including itself)*/ + for(transp = *trans + sz, ln = node->nn->lnode; ln; ln = ln->dir) + { + /*Go through each translator name in the list of names*/ + for + ( + i = 0, p = node->nn->trans + node->nn->translen - 2; + i < node->nn->ntrans; ++i + ) + { + /*position p at the beginning of the current component and + compute its length at the same time*/ + for(complen = 0; *p; --p, ++complen); + --p; + + /*move the current position backwards*/ + transp -= complen + 1; + + /*copy the current translator name into the list*/ + strcpy(transp, p + 2); + + /*we've got another translator*/ + ++*ntrans; + } + } + + /*Everything OK*/ + return 0; + }/*lnode_list_translators*/ /*----------------------------------------------------------------------------*/ |