[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v10 05/25] tools/xenstore: refactor XS_CONTROL handling
In order to allow control commands with binary data refactor handling of XS_CONTROL: - get primary command first - add maximum number of additional parameters to pass to command handler Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx> Reviewed-by: Paul Durrant <paul@xxxxxxx> --- V2: - add comment regarding max_pars (Pawel Wieczorkiewicz) V3: - addressed Paul's comments Signed-off-by: Juergen Gross <jgross@xxxxxxxx> --- tools/xenstore/xenstored_control.c | 34 ++++++++++++++++++++---------- tools/xenstore/xenstored_core.c | 3 +-- tools/xenstore/xenstored_core.h | 1 + 3 files changed, 25 insertions(+), 13 deletions(-) diff --git a/tools/xenstore/xenstored_control.c b/tools/xenstore/xenstored_control.c index 8d48ab4820..8d29db8270 100644 --- a/tools/xenstore/xenstored_control.c +++ b/tools/xenstore/xenstored_control.c @@ -30,6 +30,14 @@ struct cmd_s { char *cmd; int (*func)(void *, struct connection *, char **, int); char *pars; + /* + * max_pars can be used to limit the size of the parameter vector, + * e.g. in case of large binary parts in the parameters. + * The command is included in the count, so 1 means just the command + * without any parameter. + * 0 == no limit (the default) + */ + unsigned int max_pars; }; static int do_control_check(void *ctx, struct connection *conn, @@ -194,25 +202,29 @@ static int do_control_help(void *ctx, struct connection *conn, int do_control(struct connection *conn, struct buffered_data *in) { - int num; - int cmd; - char **vec; + unsigned int cmd, num, off; + char **vec = NULL; if (conn->id != 0) return EACCES; - num = xs_count_strings(in->buffer, in->used); - if (num < 1) + off = get_string(in, 0); + if (!off) + return EINVAL; + for (cmd = 0; cmd < ARRAY_SIZE(cmds); cmd++) + if (streq(in->buffer, cmds[cmd].cmd)) + break; + if (cmd == ARRAY_SIZE(cmds)) return EINVAL; + + num = xs_count_strings(in->buffer, in->used); + if (cmds[cmd].max_pars) + num = min(num, cmds[cmd].max_pars); vec = talloc_array(in, char *, num); if (!vec) return ENOMEM; - if (get_strings(in, vec, num) != num) + if (get_strings(in, vec, num) < num) return EIO; - for (cmd = 0; cmd < ARRAY_SIZE(cmds); cmd++) - if (streq(vec[0], cmds[cmd].cmd)) - return cmds[cmd].func(in, conn, vec + 1, num - 1); - - return EINVAL; + return cmds[cmd].func(in, conn, vec + 1, num - 1); } diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c index 50986f8b29..e1b92c3dc8 100644 --- a/tools/xenstore/xenstored_core.c +++ b/tools/xenstore/xenstored_core.c @@ -620,8 +620,7 @@ static struct buffered_data *new_buffer(void *ctx) /* Return length of string (including nul) at this offset. * If there is no nul, returns 0 for failure. */ -static unsigned int get_string(const struct buffered_data *data, - unsigned int offset) +unsigned int get_string(const struct buffered_data *data, unsigned int offset) { const char *nul; diff --git a/tools/xenstore/xenstored_core.h b/tools/xenstore/xenstored_core.h index fb59d862a2..27826c125c 100644 --- a/tools/xenstore/xenstored_core.h +++ b/tools/xenstore/xenstored_core.h @@ -142,6 +142,7 @@ const char *onearg(struct buffered_data *in); /* Break input into vectors, return the number, fill in up to num of them. */ unsigned int get_strings(struct buffered_data *data, char *vec[], unsigned int num); +unsigned int get_string(const struct buffered_data *data, unsigned int offset); void send_reply(struct connection *conn, enum xsd_sockmsg_type type, const void *data, unsigned int len); -- 2.26.2
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