diff options
Diffstat (limited to 'fs/afs/cell.c')
| -rw-r--r-- | fs/afs/cell.c | 96 |
1 files changed, 72 insertions, 24 deletions
diff --git a/fs/afs/cell.c b/fs/afs/cell.c index e19c13f059ed..0d5eeadf6121 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -13,6 +13,7 @@ #include <linux/slab.h> #include <linux/key.h> #include <linux/ctype.h> +#include <linux/dns_resolver.h> #include <linux/sched.h> #include <keys/rxrpc-type.h> #include "internal.h" @@ -30,21 +31,24 @@ static struct afs_cell *afs_cell_root; * allocate a cell record and fill in its name, VL server address list and * allocate an anonymous key */ -static struct afs_cell *afs_cell_alloc(const char *name, char *vllist) +static struct afs_cell *afs_cell_alloc(const char *name, unsigned namelen, + char *vllist) { struct afs_cell *cell; struct key *key; - size_t namelen; char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next; + char *dvllist = NULL, *_vllist = NULL; + char delimiter = ':'; int ret; - _enter("%s,%s", name, vllist); + _enter("%*.*s,%s", namelen, namelen, name ?: "", vllist); BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */ - namelen = strlen(name); - if (namelen > AFS_MAXCELLNAME) + if (namelen > AFS_MAXCELLNAME) { + _leave(" = -ENAMETOOLONG"); return ERR_PTR(-ENAMETOOLONG); + } /* allocate and initialise a cell record */ cell = kzalloc(sizeof(struct afs_cell) + namelen + 1, GFP_KERNEL); @@ -64,15 +68,35 @@ static struct afs_cell *afs_cell_alloc(const char *name, char *vllist) INIT_LIST_HEAD(&cell->vl_list); spin_lock_init(&cell->vl_lock); + /* if the ip address is invalid, try dns query */ + if (!vllist || strlen(vllist) < 7) { + ret = dns_query("afsdb", name, namelen, "ipv4", &dvllist, NULL); + if (ret < 0) { + if (ret == -ENODATA || ret == -EAGAIN || ret == -ENOKEY) + /* translate these errors into something + * userspace might understand */ + ret = -EDESTADDRREQ; + _leave(" = %d", ret); + return ERR_PTR(ret); + } + _vllist = dvllist; + + /* change the delimiter for user-space reply */ + delimiter = ','; + + } else { + _vllist = vllist; + } + /* fill in the VL server list from the rest of the string */ do { unsigned a, b, c, d; - next = strchr(vllist, ':'); + next = strchr(_vllist, delimiter); if (next) *next++ = 0; - if (sscanf(vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) + if (sscanf(_vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4) goto bad_address; if (a > 255 || b > 255 || c > 255 || d > 255) @@ -81,7 +105,7 @@ static struct afs_cell *afs_cell_alloc(const char *name, char *vllist) cell->vl_addrs[cell->vl_naddrs++].s_addr = htonl((a << 24) | (b << 16) | (c << 8) | d); - } while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (vllist = next)); + } while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (_vllist = next)); /* create a key to represent an anonymous user */ memcpy(keyname, "afs@", 4); @@ -110,32 +134,36 @@ bad_address: ret = -EINVAL; error: key_put(cell->anonymous_key); + kfree(dvllist); kfree(cell); _leave(" = %d", ret); return ERR_PTR(ret); } /* - * create a cell record - * - "name" is the name of the cell - * - "vllist" is a colon separated list of IP addresses in "a.b.c.d" format + * afs_cell_crate() - create a cell record + * @name: is the name of the cell. + * @namsesz: is the strlen of the cell name. + * @vllist: is a colon separated list of IP addresses in "a.b.c.d" format. + * @retref: is T to return the cell reference when the cell exists. */ -struct afs_cell *afs_cell_create(const char *name, char *vllist) +struct afs_cell *afs_cell_create(const char *name, unsigned namesz, + char *vllist, bool retref) { struct afs_cell *cell; int ret; - _enter("%s,%s", name, vllist); + _enter("%*.*s,%s", namesz, namesz, name ?: "", vllist); down_write(&afs_cells_sem); read_lock(&afs_cells_lock); list_for_each_entry(cell, &afs_cells, link) { - if (strcasecmp(cell->name, name) == 0) + if (strncasecmp(cell->name, name, namesz) == 0) goto duplicate_name; } read_unlock(&afs_cells_lock); - cell = afs_cell_alloc(name, vllist); + cell = afs_cell_alloc(name, namesz, vllist); if (IS_ERR(cell)) { _leave(" = %ld", PTR_ERR(cell)); up_write(&afs_cells_sem); @@ -175,8 +203,18 @@ error: return ERR_PTR(ret); duplicate_name: + if (retref && !IS_ERR(cell)) + afs_get_cell(cell); + read_unlock(&afs_cells_lock); up_write(&afs_cells_sem); + + if (retref) { + _leave(" = %p", cell); + return cell; + } + + _leave(" = -EEXIST"); return ERR_PTR(-EEXIST); } @@ -201,15 +239,13 @@ int afs_cell_init(char *rootcell) } cp = strchr(rootcell, ':'); - if (!cp) { - printk(KERN_ERR "kAFS: no VL server IP addresses specified\n"); - _leave(" = -EINVAL"); - return -EINVAL; - } + if (!cp) + _debug("kAFS: no VL server IP addresses specified"); + else + *cp++ = 0; /* allocate a cell record for the root cell */ - *cp++ = 0; - new_root = afs_cell_create(rootcell, cp); + new_root = afs_cell_create(rootcell, strlen(rootcell), cp, false); if (IS_ERR(new_root)) { _leave(" = %ld", PTR_ERR(new_root)); return PTR_ERR(new_root); @@ -229,11 +265,12 @@ int afs_cell_init(char *rootcell) /* * lookup a cell record */ -struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) +struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz, + bool dns_cell) { struct afs_cell *cell; - _enter("\"%*.*s\",", namesz, namesz, name ? name : ""); + _enter("\"%*.*s\",", namesz, namesz, name ?: ""); down_read(&afs_cells_sem); read_lock(&afs_cells_lock); @@ -247,6 +284,8 @@ struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) } } cell = ERR_PTR(-ENOENT); + if (dns_cell) + goto create_cell; found: ; } else { @@ -269,6 +308,15 @@ struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz) up_read(&afs_cells_sem); _leave(" = %p", cell); return cell; + +create_cell: + read_unlock(&afs_cells_lock); + up_read(&afs_cells_sem); + + cell = afs_cell_create(name, namesz, NULL, true); + + _leave(" = %p", cell); + return cell; } #if 0 |