diff options
Diffstat (limited to 'nsmux.c')
| -rw-r--r-- | nsmux.c | 465 |
1 files changed, 277 insertions, 188 deletions
@@ -31,7 +31,6 @@ /*----------------------------------------------------------------------------*/ #include <error.h> #include <argp.h> -#include <argz.h> #include <hurd/netfs.h> #include <fcntl.h> /*----------------------------------------------------------------------------*/ @@ -41,13 +40,6 @@ /*----------------------------------------------------------------------------*/ /*----------------------------------------------------------------------------*/ -/*--------Macros--------------------------------------------------------------*/ -/*The state modes use in open*/ -#define OPENONLY_STATE_MODES (O_CREAT | O_EXCL | O_NOLINK | O_NOTRANS \ - | O_NONBLOCK) -/*----------------------------------------------------------------------------*/ - -/*----------------------------------------------------------------------------*/ /*--------Global Variables----------------------------------------------------*/ /*The name of the server*/ char * netfs_server_name = "nsmux"; @@ -520,6 +512,7 @@ netfs_attempt_lookup LOG_MSG("netfs_attempt_lookup: '%s'", name); error_t err = 0; + int i = 0; /*If we are asked to fetch the current directory*/ if(strcmp(name, ".") == 0) @@ -564,10 +557,32 @@ netfs_attempt_lookup /*The lnode corresponding to the entry we are supposed to fetch*/ lnode_t * lnode; + /*The position of ',,' in the name*/ + char * sep; + + /*A pointer for various operations on strings*/ + char * str; + + /*A list of translators*/ + char * trans = NULL; + + /*The number of translators in the list*/ + size_t ntrans; + + /*The length of the list of translators*/ + size_t translen; + + /*Is the looked up file a directory*/ + int isdir; + /*Finalizes the execution of this function*/ void finalize(void) { + /*Free the list of translators, if it has been allocated*/ + if(trans) + free(trans); + /*If some errors have occurred*/ if(err) { @@ -625,6 +640,9 @@ netfs_attempt_lookup { /*do not set the port*/ p = MACH_PORT_NULL; + + /*remember we do not have a directory*/ + isdir = 0; } else { @@ -634,6 +652,9 @@ netfs_attempt_lookup { return EBADF; /*not enough rights?*/ } + + /*we have a directory here*/ + isdir = 1; } /*Try to find an lnode called `name` under the lnode corresponding to `dir`*/ @@ -653,28 +674,13 @@ netfs_attempt_lookup /*install the new lnode into the directory*/ lnode_install(dir->nn->lnode, lnode); } - else - { - /*TODO: Remove the code from here and put it into the caller block, - so that we can decide there whether to remove translators and - *which* ones to remove*/ - - /*free the list of translators associated with this node, if - such a list exists*/ - if(lnode->trans) - { - free(lnode->trans); - lnode->trans = NULL; - lnode->ntrans = lnode->translen = 0; - } - } - + /*Obtain the node corresponding to this lnode*/ err = ncache_node_lookup(lnode, node); /*Remove an extra reference from the lnode*/ lnode_ref_remove(lnode); - + /*If the lookup in the cache failed*/ if(err) { @@ -686,6 +692,12 @@ netfs_attempt_lookup /*Store the port in the node*/ (*node)->nn->port = p; + /*Fill in the flag about the node being a directory*/ + if(isdir) + lnode->flags |= FLAG_LNODE_DIR; + else + lnode->flags &= ~FLAG_LNODE_DIR; + /*Construct the full path to the node*/ err = lnode_path_construct(lnode, NULL); if(err) @@ -701,12 +713,6 @@ netfs_attempt_lookup return 0; }/*lookup*/ - /*The position of ',,' in the name*/ - char * sep; - - /*A pointer for various operations on strings*/ - char * str; - /*While pairs of commas can still be found in the name*/ for(sep = strstr(name, ",,"); sep; sep = strstr(sep, ",,")) { @@ -760,58 +766,219 @@ netfs_attempt_lookup /*duplicate the part of the name containing the list of translators and store the copy in the lnode*/ - lnode->trans = strdup(sep); - if(!lnode->trans) + trans = strdup(sep); + if(!trans) { finalize(); return err; } - /*free the copy of the name*/ - /*we've just copied the pointer, so don't free it*/ - /*free(name_cpy);*/ - /*obtain a pointer to the beginning of the list of translators*/ - str = lnode->trans; + str = trans; - /*used to process escaped commas*/ - /*char * p;*/ + /*a pointer for removal of extra commas*/ + char * p; /*Go through the list of translators*/ - for(lnode->ntrans = 0; *str; ++str) + for(translen = ntrans = 0; *str; ++str) { - /*Commas are not allowed in translator names*/ -#if 0 - /*If we are now situated at an escaped comma*/ - if((*str == '\\') && (str[1] == ',')) - { - /*shift everything left in the string to remove the escaping backslash*/ - for(p = str; *p; *p = p[1], ++p); - - /*count a single character and step forward*/ - ++lnode->translen; - continue; - } -#endif - /*If the current character is a comma*/ if(*str == ',') { + /*While the next characters are commas, too*/ + for(; str[1] == ',';) + { + /*shift the string leftwards*/ + for(p = str + 1; *p; p[-1] = *p, ++p); + p[-1] = 0; + } + + /*If the next character is the terminal 0*/ + if(!str[1]) + { + /*this comma is extra*/ + *str = 0; + break; + } + /*make it a separator zero*/ *str = 0; /*we have just finished going through a new component*/ - ++lnode->ntrans; + ++ntrans; } /*take the current character into account*/ - ++lnode->translen; + ++translen; } /*take into consideration the last element in the list, which does not end in a comma and the corresponding terminal 0*/ - ++lnode->ntrans; - ++lnode->translen; + ++ntrans; + ++translen; + + /*If there are no translators set upon the current node*/ + if(!lnode->trans) + { + /*copy the list of translators we have just built in the lnode*/ + lnode->trans = trans; + lnode->ntrans = ntrans; + lnode->translen = translen; + + /*If the node has already been fully translated before and it's + not a directory*/ + /*We don't need to set the whole collection of translators, + both inherited and the ones in lnode->trans. The latter + are only necessary. Directories, on the other hand, cannot + bear translators on them.*/ + if + ( + (lnode->flags & FLAG_LNODE_TRANSLATED) + && !(lnode->flags & FLAG_LNODE_DIR) + ) + { + /*Go through the list of translators*/ + for(str = trans, i = 0; i < ntrans; ++i) + { + /*set the translator specified in the current component*/ + err = node_set_translator(dir, *node, str); + if(err) + { + finalize(); + return 0; /*TODO: A better way to fight errors here*/ + } + + /*skip the current component*/ + str += strlen(str) + 1; + } + + /*we don't own the list of translators any more*/ + trans = NULL; + ntrans = 0; + translen = 0; + + /*here the lookup is successful*/ + err = 0; + finalize(); + return err; + } + + /*we don't own the list of translators any more*/ + trans = NULL; + ntrans = 0; + translen = 0; + } + else + { + /*If the current node is not a directory*/ + if(!isdir) + { + /*obtain the minimal of the lengths of the lists of translators*/ + size_t minlen = + (translen < lnode->translen) ? (translen) : (lnode->translen); + + /*the number of similar translators*/ + size_t similar = 0; + + /*the current position in the list*/ + size_t i; + + /*Go through the lists of translators*/ + for(i = 0; i < minlen; ++i) + { + /*If the current characters are different, stop here*/ + if(trans[i] != lnode->trans[i]) + break; + + /*If the current character marks the end of a translator name*/ + if(trans[i] == 0) + /*one more matching translator*/ + ++similar; + } + + /*While all not matching translators have not been removed*/ + size_t j; + for(j = 0; j < lnode->ntrans - similar; ++j) + { + /*remove one more translator*/ + err = node_kill_translator(dir, *node); + if(err) + { + finalize(); + return err; + } + } + + /*obtain the pointer to the first not matching position*/ + str = trans + i; + + /*seek to the beginning of the current translator name*/ + for(; (str > trans) && *str; --str); + + /*While the required new translators have not been set*/ + for(i = 0; i < ntrans - similar; ++i) + { + /*set the current translator on the file*/ + err = node_set_translator(dir, *node, str); + if(err) + { + finalize(); + return err; + } + + /*skip the current translator*/ + str += strlen(str) + 1; + } + } + /*We have looked up a directory*/ + else + { + /*If the length of the lists of translators are the same*/ + if((lnode->translen = translen) && (lnode->ntrans == ntrans)) + { + /*check each character of the list of translators*/ + int i; + for(i = 0; (i < translen) && (lnode->trans[i] == trans[i]); ++i); + + /*If the lists coincide*/ + if(i == translen) + { + /*the lookup has finished successfully here*/ + err = 0; + finalize(); + return err; + } + } + + /*unlock the directory in which we are at the moment*/ + mutex_unlock(&dir->lock); + + /*kill all translators on all children of this node*/ + node_kill_all_translators(*node); + + /*lock the directory back*/ + mutex_lock(&dir->lock); + } + + /*destroy the list of translators in the current node*/ + free(lnode->trans); + + /*put the new list in the node*/ + lnode->trans = trans; + lnode->ntrans = ntrans; + lnode->translen = translen; + + /*all required translators have been already applied on this node*/ + /*lnode->flags |= FLAG_LNODE_TRANSLATED;*/ + + /*we don't own the list of translators any more*/ + trans = NULL; + + /*the lookup is already finished here*/ + err = 0; + finalize(); + return err; + } } /*The control sequence ',,' has not been found*/ else @@ -823,14 +990,51 @@ netfs_attempt_lookup finalize(); return err; } + + /*If there are some translators set on this file*/ + if(lnode->trans) + { + /*unlock the directory*/ + mutex_unlock(&dir->lock); + + /*kill all translators on this node*/ + node_kill_all_translators(*node); + + /*lock the directory again*/ + mutex_lock(&dir->lock); + + /*all translators have been succesfully set here*/ + /*lnode->flags |= FLAG_LNODE_TRANSLATED;*/ + + /*the lookup has finished successfully here*/ + /*The translators inherited from parents survive throughout + the previous loop*/ + err = 0; + finalize(); + return err; + } } - /*The list of translators inherited from its ancestors*/ - char * trans; - - /*the number of translators*/ - size_t ntrans; - + /*If we have a directory*/ + if(isdir) + { + /*FIXME: It means we've got a directory, and no translators are set on + directories. The point is that nsmux should mainly handle libtrivs-based + translators, which should not operate on directories.*/ + err = 0; + finalize(); + return err; + } + + /*If the current node has already been successfully translated*/ + if(lnode->flags & FLAG_LNODE_TRANSLATED) + { + /*no additional translators must set on this file*/ + err = 0; + finalize(); + return err; + } + /*Obtain the list of inherited translators*/ err = lnode_list_translators(lnode, &trans, &ntrans); if(err) @@ -847,139 +1051,24 @@ netfs_attempt_lookup return 0; } - int i; - - /*If there is a port open for the current node*/ - if((*node)->nn->port != MACH_PORT_NULL) - { - /*close the port, since we will open it when starting translators*/ - PORT_DEALLOC((*node)->nn->port); - } - - /*Opens a port to the file at the request of fshelp_start_translator*/ - error_t - open_port - ( - int flags, - mach_port_t * underlying, - mach_msg_type_name_t * underlying_type, - task_t task, - void * cookie /*some additional information, not used here*/ - ) - { - /*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; - - /*Store the result in the parameters*/ - *underlying = p; - *underlying_type = MACH_MSG_TYPE_COPY_SEND; - - /*Here everything is OK*/ - return 0; - }/*open_port*/ - - /*Adds a "/hurd/" at the beginning of the translator name, if required*/ - char * - put_in_hurd - ( - char * name - ) - { - /*If the path to the translator is absolute, return a copy of the name*/ - /*TODO: A better decision technique on whether we have to add the prefix*/ - if(name[0] == '/') - return strdup(name); - - /*Compute the length of the name*/ - size_t len = strlen(name); - - /*Try to allocate new memory*/ - char * full = malloc(6/*strlen("/hurd/")*/ + len + 1); - if(!full) - return NULL; - - /*Construct the name*/ - strcpy(full, "/hurd/"); - strcpy(full + 6, name); - full[6 + len] = 0; - - /*Return the full path*/ - return full; - }/*put_in_hurd*/ - - /*A copy (possibly extended) of the name of the translator*/ - char * ext; - - /*The length of the current component in the list of translators*/ - size_t complen; - - /*The holders of argz-transformed translator name and arguments*/ - char * argz = NULL; - size_t argz_len = 0; - - /*The control port for the active translator*/ - mach_port_t active_control; - /*Go through the list of translators*/ for(str = trans, i = 0; i < ntrans; ++i) { - /*obtain the length of the current component*/ - complen = strlen(str); - - /*obtain a copy (possibly extended) of the name*/ - ext = put_in_hurd(str); - if(!ext) - { - err = ENOMEM; - finalize(); - return err; - } - - /*TODO: Better argument-parsing?*/ - - /*obtain the argz version of str*/ - err = argz_create_sep(ext, ' ', &argz, &argz_len); + /*set the translator specified in the current component*/ + err = node_set_translator(dir, *node, str); if(err) { finalize(); - return err; + return 0; /*TODO: A better way to fight errors here*/ } - - /*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) - { - finalize(); - 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 - ); - if(err) - { - finalize(); - return err; - } - - /*deallocate the port we have just opened*/ - PORT_DEALLOC(p); - + /*skip the current component*/ - str += complen + 1; + str += strlen(str) + 1; } + /*All translators have been succesfully set on this node*/ + lnode->flags |= FLAG_LNODE_TRANSLATED; + /*Everything OK here*/ finalize(); return err; |