From c76bf6bb8fbbb233a7d3641e09229d23747d5ee3 Mon Sep 17 00:00:00 2001 From: Nikolay Nikolaev Date: Tue, 27 May 2014 15:04:15 +0300 Subject: [PATCH] Add chardev API qemu_chr_fe_get_msgfds This extends the existing qemu_chr_fe_get_msgfd by allowing to read a set of fds. The function for receiving the fds - unix_process_msgfd is extended to allocate the needed array size. Signed-off-by: Antonios Motakis Signed-off-by: Nikolay Nikolaev Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- include/sysemu/char.h | 15 +++++++- qemu-char.c | 85 ++++++++++++++++++++++++++++++++----------- 2 files changed, 78 insertions(+), 22 deletions(-) diff --git a/include/sysemu/char.h b/include/sysemu/char.h index 1aa080e00a..930aaf1abe 100644 --- a/include/sysemu/char.h +++ b/include/sysemu/char.h @@ -61,7 +61,7 @@ struct CharDriverState { GSource *(*chr_add_watch)(struct CharDriverState *s, GIOCondition cond); void (*chr_update_read_handler)(struct CharDriverState *s); int (*chr_ioctl)(struct CharDriverState *s, int cmd, void *arg); - int (*get_msgfd)(struct CharDriverState *s); + int (*get_msgfds)(struct CharDriverState *s, int* fds, int num); int (*set_msgfds)(struct CharDriverState *s, int *fds, int num); int (*chr_add_client)(struct CharDriverState *chr, int fd); IOEventHandler *chr_event; @@ -229,6 +229,19 @@ int qemu_chr_fe_ioctl(CharDriverState *s, int cmd, void *arg); */ int qemu_chr_fe_get_msgfd(CharDriverState *s); +/** + * @qemu_chr_fe_get_msgfds: + * + * For backends capable of fd passing, return the number of file received + * descriptors and fills the fds array up to num elements + * + * Returns: -1 if fd passing isn't supported or there are no pending file + * descriptors. If file descriptors are returned, subsequent calls to + * this function will return -1 until a client sends a new set of file + * descriptors. + */ +int qemu_chr_fe_get_msgfds(CharDriverState *s, int *fds, int num); + /** * @qemu_chr_fe_set_msgfds: * diff --git a/qemu-char.c b/qemu-char.c index f9709d9d0d..b9bef443de 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -204,7 +204,13 @@ void qemu_chr_be_write(CharDriverState *s, uint8_t *buf, int len) int qemu_chr_fe_get_msgfd(CharDriverState *s) { - return s->get_msgfd ? s->get_msgfd(s) : -1; + int fd; + return (qemu_chr_fe_get_msgfds(s, &fd, 1) >= 0) ? fd : -1; +} + +int qemu_chr_fe_get_msgfds(CharDriverState *s, int *fds, int len) +{ + return s->get_msgfds ? s->get_msgfds(s, fds, len) : -1; } int qemu_chr_fe_set_msgfds(CharDriverState *s, int *fds, int num) @@ -2337,7 +2343,8 @@ typedef struct { int do_telnetopt; int do_nodelay; int is_unix; - int msgfd; + int *read_msgfds; + int read_msgfds_num; int *write_msgfds; int write_msgfds_num; } TCPCharDriver; @@ -2469,12 +2476,20 @@ static void tcp_chr_process_IAC_bytes(CharDriverState *chr, *size = j; } -static int tcp_get_msgfd(CharDriverState *chr) +static int tcp_get_msgfds(CharDriverState *chr, int *fds, int num) { TCPCharDriver *s = chr->opaque; - int fd = s->msgfd; - s->msgfd = -1; - return fd; + int to_copy = (s->read_msgfds_num < num) ? s->read_msgfds_num : num; + + if (to_copy) { + memcpy(fds, s->read_msgfds, to_copy * sizeof(int)); + + g_free(s->read_msgfds); + s->read_msgfds = 0; + s->read_msgfds_num = 0; + } + + return to_copy; } static int tcp_set_msgfds(CharDriverState *chr, int *fds, int num) @@ -2503,26 +2518,46 @@ static void unix_process_msgfd(CharDriverState *chr, struct msghdr *msg) struct cmsghdr *cmsg; for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) { - int fd; + int fd_size, i; - if (cmsg->cmsg_len != CMSG_LEN(sizeof(int)) || + if (cmsg->cmsg_len < CMSG_LEN(sizeof(int)) || cmsg->cmsg_level != SOL_SOCKET || - cmsg->cmsg_type != SCM_RIGHTS) + cmsg->cmsg_type != SCM_RIGHTS) { continue; + } - fd = *((int *)CMSG_DATA(cmsg)); - if (fd < 0) + fd_size = cmsg->cmsg_len - CMSG_LEN(0); + + if (!fd_size) { continue; + } - /* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */ - qemu_set_block(fd); + /* close and clean read_msgfds */ + for (i = 0; i < s->read_msgfds_num; i++) { + close(s->read_msgfds[i]); + } -#ifndef MSG_CMSG_CLOEXEC - qemu_set_cloexec(fd); -#endif - if (s->msgfd != -1) - close(s->msgfd); - s->msgfd = fd; + if (s->read_msgfds_num) { + g_free(s->read_msgfds); + } + + s->read_msgfds_num = fd_size / sizeof(int); + s->read_msgfds = g_malloc(fd_size); + memcpy(s->read_msgfds, CMSG_DATA(cmsg), fd_size); + + for (i = 0; i < s->read_msgfds_num; i++) { + int fd = s->read_msgfds[i]; + if (fd < 0) { + continue; + } + + /* O_NONBLOCK is preserved across SCM_RIGHTS so reset it */ + qemu_set_block(fd); + + #ifndef MSG_CMSG_CLOEXEC + qemu_set_cloexec(fd); + #endif + } } } @@ -2746,6 +2781,7 @@ static gboolean tcp_chr_accept(GIOChannel *channel, GIOCondition cond, void *opa static void tcp_chr_close(CharDriverState *chr) { TCPCharDriver *s = chr->opaque; + int i; if (s->fd >= 0) { remove_fd_in_watch(chr); if (s->chan) { @@ -2763,6 +2799,12 @@ static void tcp_chr_close(CharDriverState *chr) } closesocket(s->listen_fd); } + if (s->read_msgfds_num) { + for (i = 0; i < s->read_msgfds_num; i++) { + close(s->read_msgfds[i]); + } + g_free(s->read_msgfds); + } if (s->write_msgfds_num) { g_free(s->write_msgfds); } @@ -2794,7 +2836,8 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, s->connected = 0; s->fd = -1; s->listen_fd = -1; - s->msgfd = -1; + s->read_msgfds = 0; + s->read_msgfds_num = 0; s->write_msgfds = 0; s->write_msgfds_num = 0; @@ -2827,7 +2870,7 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, chr->chr_write = tcp_chr_write; chr->chr_sync_read = tcp_chr_sync_read; chr->chr_close = tcp_chr_close; - chr->get_msgfd = tcp_get_msgfd; + chr->get_msgfds = tcp_get_msgfds; chr->set_msgfds = tcp_set_msgfds; chr->chr_add_client = tcp_chr_add_client; chr->chr_add_watch = tcp_chr_add_watch;