| Message ID | 20231101093325.30302-12-jgross@suse.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | tools: enable xenstore-stubdom to use 9pfs | expand |
On Wed, Nov 1, 2023 at 6:48 AM Juergen Gross <jgross@suse.com> wrote: > > Add the create request of the 9pfs protocol. > > Signed-off-by: Juergen Gross <jgross@suse.com> > --- > tools/xenlogd/io.c | 133 +++++++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 133 insertions(+) > > diff --git a/tools/xenlogd/io.c b/tools/xenlogd/io.c > index 2607095e51..34f137be1b 100644 > --- a/tools/xenlogd/io.c > +++ b/tools/xenlogd/io.c > @@ -31,6 +31,7 @@ > #define P9_CMD_ERROR 107 > #define P9_CMD_WALK 110 > #define P9_CMD_OPEN 112 > +#define P9_CMD_CREATE 114 > #define P9_CMD_CLUNK 120 > > /* P9 protocol open flags. */ > @@ -41,6 +42,12 @@ > #define P9_OTRUNC 0x10 /* or'ed in, truncate file first */ > #define P9_OREMOVE 0x40 /* or'ed in, remove file after clunk */ > > +/* P9 protocol create permission masks. */ > +#define P9_CREATE_PERM_DIR 0x80000000 > +#define P9_CREATE_PERM_NOTSUPP 0x03b00000 /* link, symlink, ... */ > +#define P9_CREATE_PERM_DIR_MASK 0777 > +#define P9_CREATE_PERM_FILE_MASK 0666 > + > #define P9_MIN_MSIZE 2048 > #define P9_VERSION "9P2000.u" > #define P9_WALK_MAXELEM 16 > @@ -861,6 +868,128 @@ static void p9_open(device *device, struct p9_header *hdr) > fill_buffer(device, hdr->cmd + 1, hdr->tag, "QU", &qid, &iounit); > } > > +static void p9_create(device *device, struct p9_header *hdr) > +{ > + uint32_t fid; > + unsigned int name_off; > + uint32_t perm; > + uint8_t mode; > + unsigned int ext_off; > + struct p9_fid *fidp; > + struct p9_fid *new_fidp; > + char *path; > + struct stat st; > + struct p9_qid qid; > + uint32_t iounit; > + int flags; > + int ret; > + > + ret = fill_data(device, "USUbS", &fid, &name_off, &perm, &mode, &ext_off); > + if ( ret != 5 ) > + { > + p9_error(device, hdr->tag, EINVAL); > + return; > + } > + > + if ( !name_ok(device->str + name_off) ) > + { > + p9_error(device, hdr->tag, ENOENT); > + return; > + } > + > + if ( perm & P9_CREATE_PERM_NOTSUPP ) > + { > + p9_error(device, hdr->tag, EINVAL); > + return; > + } > + > + fidp = find_fid(device, fid); > + if ( !fidp || fidp->opened ) > + { > + p9_error(device, hdr->tag, EINVAL); > + return; > + } > + > + path = malloc(strlen(fidp->path) + strlen(device->str + name_off) + 2 - > + strlen(device->host_path)); > + if ( !path ) > + { > + p9_error(device, hdr->tag, ENOMEM); > + return; > + } > + sprintf(path, "%s/%s", fidp->path + strlen(device->host_path), > + device->str + name_off); > + new_fidp = alloc_fid_mem(device, fid, path); > + free(path); > + if ( !new_fidp ) > + { > + p9_error(device, hdr->tag, ENOMEM); > + return; > + } > + > + if ( perm & P9_CREATE_PERM_DIR ) > + { > + if ( mode != P9_OREAD ) > + { > + p9_error(device, hdr->tag, EINVAL); > + free(new_fidp); > + return; > + } > + if ( mkdir(new_fidp->path, perm & P9_CREATE_PERM_DIR_MASK) < 0 ) > + { > + p9_error(device, hdr->tag, errno); > + free(new_fidp); > + return; > + } > + > + XEN_TAILQ_REMOVE(&device->fids, fidp, list); > + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); > + free(fidp); > + fidp = new_fidp; > + > + fidp->data = opendir(fidp->path); > + if ( !fidp->data ) > + { > + p9_error(device, hdr->tag, errno); > + return; > + } > + fidp->fd = dirfd(fidp->data); > + } > + else > + { > + flags = open_flags_from_mode(mode); > + if ( flags < 0 ) > + { > + p9_error(device, hdr->tag, EINVAL); > + free(new_fidp); > + return; > + } > + > + XEN_TAILQ_REMOVE(&device->fids, """fidp, list); > + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); > + free(fidp); > + fidp = new_fidp; > + > + fidp->fd = creat(fidp->path, flags); https://ericvh.github.io/9p-rfc/rfc9p2000.html#anchor29 """ The create request asks the file server to create a new file with the name supplied, in the directory (dir) represented by fid, and requires write permission in the directory. The owner of the file is the implied user id of the request, the group of the file is the same as dir, and the permissions are the value of perm & (~0666 | (dir.perm & 0666)) if a regular file is being created and perm & (~0777 | (dir.perm & 0777)) if a directory is being created. This means, for example, that if the create allows read permission to others, but the containing directory does not, then the created file will not allow others to read the file. """ So P9_CREATE_PERM_FILE_MASK (which is otherwise unused) should be incorporated. Also the mode and the permissions are handled independently: """ Finally, the newly created file is opened according to mode, and fid will represent the newly opened file. Mode is not checked against the permissions in perm. """ I think fidp->mode should be set in here somewhere based on mode. And `flags` for creat should be derived from the incoming perms. Regards, Jason
On 06.11.23 20:53, Jason Andryuk wrote: > On Wed, Nov 1, 2023 at 6:48 AM Juergen Gross <jgross@suse.com> wrote: >> >> Add the create request of the 9pfs protocol. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> --- >> tools/xenlogd/io.c | 133 +++++++++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 133 insertions(+) >> >> diff --git a/tools/xenlogd/io.c b/tools/xenlogd/io.c >> index 2607095e51..34f137be1b 100644 >> --- a/tools/xenlogd/io.c >> +++ b/tools/xenlogd/io.c >> @@ -31,6 +31,7 @@ >> #define P9_CMD_ERROR 107 >> #define P9_CMD_WALK 110 >> #define P9_CMD_OPEN 112 >> +#define P9_CMD_CREATE 114 >> #define P9_CMD_CLUNK 120 >> >> /* P9 protocol open flags. */ >> @@ -41,6 +42,12 @@ >> #define P9_OTRUNC 0x10 /* or'ed in, truncate file first */ >> #define P9_OREMOVE 0x40 /* or'ed in, remove file after clunk */ >> >> +/* P9 protocol create permission masks. */ >> +#define P9_CREATE_PERM_DIR 0x80000000 >> +#define P9_CREATE_PERM_NOTSUPP 0x03b00000 /* link, symlink, ... */ >> +#define P9_CREATE_PERM_DIR_MASK 0777 >> +#define P9_CREATE_PERM_FILE_MASK 0666 >> + >> #define P9_MIN_MSIZE 2048 >> #define P9_VERSION "9P2000.u" >> #define P9_WALK_MAXELEM 16 >> @@ -861,6 +868,128 @@ static void p9_open(device *device, struct p9_header *hdr) >> fill_buffer(device, hdr->cmd + 1, hdr->tag, "QU", &qid, &iounit); >> } >> >> +static void p9_create(device *device, struct p9_header *hdr) >> +{ >> + uint32_t fid; >> + unsigned int name_off; >> + uint32_t perm; >> + uint8_t mode; >> + unsigned int ext_off; >> + struct p9_fid *fidp; >> + struct p9_fid *new_fidp; >> + char *path; >> + struct stat st; >> + struct p9_qid qid; >> + uint32_t iounit; >> + int flags; >> + int ret; >> + >> + ret = fill_data(device, "USUbS", &fid, &name_off, &perm, &mode, &ext_off); >> + if ( ret != 5 ) >> + { >> + p9_error(device, hdr->tag, EINVAL); >> + return; >> + } >> + >> + if ( !name_ok(device->str + name_off) ) >> + { >> + p9_error(device, hdr->tag, ENOENT); >> + return; >> + } >> + >> + if ( perm & P9_CREATE_PERM_NOTSUPP ) >> + { >> + p9_error(device, hdr->tag, EINVAL); >> + return; >> + } >> + >> + fidp = find_fid(device, fid); >> + if ( !fidp || fidp->opened ) >> + { >> + p9_error(device, hdr->tag, EINVAL); >> + return; >> + } >> + >> + path = malloc(strlen(fidp->path) + strlen(device->str + name_off) + 2 - >> + strlen(device->host_path)); >> + if ( !path ) >> + { >> + p9_error(device, hdr->tag, ENOMEM); >> + return; >> + } >> + sprintf(path, "%s/%s", fidp->path + strlen(device->host_path), >> + device->str + name_off); >> + new_fidp = alloc_fid_mem(device, fid, path); >> + free(path); >> + if ( !new_fidp ) >> + { >> + p9_error(device, hdr->tag, ENOMEM); >> + return; >> + } >> + >> + if ( perm & P9_CREATE_PERM_DIR ) >> + { >> + if ( mode != P9_OREAD ) >> + { >> + p9_error(device, hdr->tag, EINVAL); >> + free(new_fidp); >> + return; >> + } >> + if ( mkdir(new_fidp->path, perm & P9_CREATE_PERM_DIR_MASK) < 0 ) >> + { >> + p9_error(device, hdr->tag, errno); >> + free(new_fidp); >> + return; >> + } >> + >> + XEN_TAILQ_REMOVE(&device->fids, fidp, list); >> + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); >> + free(fidp); >> + fidp = new_fidp; >> + >> + fidp->data = opendir(fidp->path); >> + if ( !fidp->data ) >> + { >> + p9_error(device, hdr->tag, errno); >> + return; >> + } >> + fidp->fd = dirfd(fidp->data); >> + } >> + else >> + { >> + flags = open_flags_from_mode(mode); >> + if ( flags < 0 ) >> + { >> + p9_error(device, hdr->tag, EINVAL); >> + free(new_fidp); >> + return; >> + } >> + >> + XEN_TAILQ_REMOVE(&device->fids, """fidp, list); >> + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); >> + free(fidp); >> + fidp = new_fidp; >> + >> + fidp->fd = creat(fidp->path, flags); > > https://ericvh.github.io/9p-rfc/rfc9p2000.html#anchor29 > """ > The create request asks the file server to create a new file with the > name supplied, in the directory (dir) represented by fid, and requires > write permission in the directory. The owner of the file is the > implied user id of the request, the group of the file is the same as > dir, and the permissions are the value of > > perm & (~0666 | (dir.perm & 0666)) > > if a regular file is being created and > > perm & (~0777 | (dir.perm & 0777)) > > if a directory is being created. This means, for example, that if the > create allows read permission to others, but the containing directory > does not, then the created file will not allow others to read the > file. > """ > > So P9_CREATE_PERM_FILE_MASK (which is otherwise unused) should be > incorporated. Also the mode and the permissions are handled > independently: > """ > Finally, the newly created file is opened according to mode, and fid > will represent the newly opened file. Mode is not checked against the > permissions in perm. > """ > > I think fidp->mode should be set in here somewhere based on mode. And > `flags` for creat should be derived from the incoming perms. Yes, I agree. Juergen
diff --git a/tools/xenlogd/io.c b/tools/xenlogd/io.c index 2607095e51..34f137be1b 100644 --- a/tools/xenlogd/io.c +++ b/tools/xenlogd/io.c @@ -31,6 +31,7 @@ #define P9_CMD_ERROR 107 #define P9_CMD_WALK 110 #define P9_CMD_OPEN 112 +#define P9_CMD_CREATE 114 #define P9_CMD_CLUNK 120 /* P9 protocol open flags. */ @@ -41,6 +42,12 @@ #define P9_OTRUNC 0x10 /* or'ed in, truncate file first */ #define P9_OREMOVE 0x40 /* or'ed in, remove file after clunk */ +/* P9 protocol create permission masks. */ +#define P9_CREATE_PERM_DIR 0x80000000 +#define P9_CREATE_PERM_NOTSUPP 0x03b00000 /* link, symlink, ... */ +#define P9_CREATE_PERM_DIR_MASK 0777 +#define P9_CREATE_PERM_FILE_MASK 0666 + #define P9_MIN_MSIZE 2048 #define P9_VERSION "9P2000.u" #define P9_WALK_MAXELEM 16 @@ -861,6 +868,128 @@ static void p9_open(device *device, struct p9_header *hdr) fill_buffer(device, hdr->cmd + 1, hdr->tag, "QU", &qid, &iounit); } +static void p9_create(device *device, struct p9_header *hdr) +{ + uint32_t fid; + unsigned int name_off; + uint32_t perm; + uint8_t mode; + unsigned int ext_off; + struct p9_fid *fidp; + struct p9_fid *new_fidp; + char *path; + struct stat st; + struct p9_qid qid; + uint32_t iounit; + int flags; + int ret; + + ret = fill_data(device, "USUbS", &fid, &name_off, &perm, &mode, &ext_off); + if ( ret != 5 ) + { + p9_error(device, hdr->tag, EINVAL); + return; + } + + if ( !name_ok(device->str + name_off) ) + { + p9_error(device, hdr->tag, ENOENT); + return; + } + + if ( perm & P9_CREATE_PERM_NOTSUPP ) + { + p9_error(device, hdr->tag, EINVAL); + return; + } + + fidp = find_fid(device, fid); + if ( !fidp || fidp->opened ) + { + p9_error(device, hdr->tag, EINVAL); + return; + } + + path = malloc(strlen(fidp->path) + strlen(device->str + name_off) + 2 - + strlen(device->host_path)); + if ( !path ) + { + p9_error(device, hdr->tag, ENOMEM); + return; + } + sprintf(path, "%s/%s", fidp->path + strlen(device->host_path), + device->str + name_off); + new_fidp = alloc_fid_mem(device, fid, path); + free(path); + if ( !new_fidp ) + { + p9_error(device, hdr->tag, ENOMEM); + return; + } + + if ( perm & P9_CREATE_PERM_DIR ) + { + if ( mode != P9_OREAD ) + { + p9_error(device, hdr->tag, EINVAL); + free(new_fidp); + return; + } + if ( mkdir(new_fidp->path, perm & P9_CREATE_PERM_DIR_MASK) < 0 ) + { + p9_error(device, hdr->tag, errno); + free(new_fidp); + return; + } + + XEN_TAILQ_REMOVE(&device->fids, fidp, list); + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); + free(fidp); + fidp = new_fidp; + + fidp->data = opendir(fidp->path); + if ( !fidp->data ) + { + p9_error(device, hdr->tag, errno); + return; + } + fidp->fd = dirfd(fidp->data); + } + else + { + flags = open_flags_from_mode(mode); + if ( flags < 0 ) + { + p9_error(device, hdr->tag, EINVAL); + free(new_fidp); + return; + } + + XEN_TAILQ_REMOVE(&device->fids, fidp, list); + XEN_TAILQ_INSERT_HEAD(&device->fids, new_fidp, list); + free(fidp); + fidp = new_fidp; + + fidp->fd = creat(fidp->path, flags); + if ( fidp->fd < 0 ) + { + p9_error(device, hdr->tag, errno); + return; + } + } + + if ( stat(fidp->path, &st) < 0 ) + { + p9_error(device, hdr->tag, errno); + return; + } + fill_qid(fidp->path, &qid, &st); + iounit = get_iounit(device, &st); + fidp->opened = true; + + fill_buffer(device, hdr->cmd + 1, hdr->tag, "QU", &qid, &iounit); +} + static void p9_clunk(device *device, struct p9_header *hdr) { uint32_t fid; @@ -964,6 +1093,10 @@ void *io_thread(void *arg) p9_open(device, &hdr); break; + case P9_CMD_CREATE: + p9_create(device, &hdr); + break; + case P9_CMD_CLUNK: p9_clunk(device, &hdr); break;
Add the create request of the 9pfs protocol. Signed-off-by: Juergen Gross <jgross@suse.com> --- tools/xenlogd/io.c | 133 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 133 insertions(+)