This function will attempt to read data from the chardev trying to fill the buffer up to the given length. Add tcp_chr_disconnect to reuse disconnection code where needed.
Signed-off-by: Antonios Motakis <a.mota...@virtualopensystems.com> Signed-off-by: Nikolay Nikolaev <n.nikol...@virtualopensystems.com> --- include/sysemu/char.h | 14 +++++++++ qemu-char.c | 83 ++++++++++++++++++++++++++++++++++++++++++++------- 2 files changed, 87 insertions(+), 10 deletions(-) diff --git a/include/sysemu/char.h b/include/sysemu/char.h index b81a6ff..9981a6a 100644 --- a/include/sysemu/char.h +++ b/include/sysemu/char.h @@ -56,6 +56,8 @@ typedef void IOEventHandler(void *opaque, int event); struct CharDriverState { void (*init)(struct CharDriverState *s); int (*chr_write)(struct CharDriverState *s, const uint8_t *buf, int len); + int (*chr_sync_read)(struct CharDriverState *s, + const uint8_t *buf, int len); 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); @@ -189,6 +191,18 @@ int qemu_chr_fe_write(CharDriverState *s, const uint8_t *buf, int len); int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len); /** + * @qemu_chr_fe_read_all: + * + * Read data to a buffer from the back end. + * + * @buf the data buffer + * @len the number of bytes to read + * + * Returns: the number of bytes read + */ +int qemu_chr_fe_read_all(CharDriverState *s, uint8_t *buf, int len); + +/** * @qemu_chr_fe_ioctl: * * Issue a device specific ioctl to a backend. diff --git a/qemu-char.c b/qemu-char.c index 4d50838..ff2e9d8 100644 --- a/qemu-char.c +++ b/qemu-char.c @@ -84,6 +84,7 @@ #include "ui/qemu-spice.h" #define READ_BUF_LEN 4096 +#define READ_RETRIES 10 /***********************************************************/ /* character device */ @@ -145,6 +146,41 @@ int qemu_chr_fe_write_all(CharDriverState *s, const uint8_t *buf, int len) return offset; } +int qemu_chr_fe_read_all(CharDriverState *s, uint8_t *buf, int len) +{ + int offset = 0, counter = 10; + int res; + + if (!s->chr_sync_read) { + return 0; + } + + while (offset < len) { + do { + res = s->chr_sync_read(s, buf + offset, len - offset); + if (res == -1 && errno == EAGAIN) { + g_usleep(100); + } + } while (res == -1 && errno == EAGAIN); + + if (res == 0) { + break; + } + + if (res < 0) { + return res; + } + + offset += res; + + if (!counter--) { + break; + } + } + + return offset; +} + int qemu_chr_fe_ioctl(CharDriverState *s, int cmd, void *arg) { if (!s->chr_ioctl) @@ -2453,6 +2489,23 @@ static GSource *tcp_chr_add_watch(CharDriverState *chr, GIOCondition cond) return g_io_create_watch(s->chan, cond); } +static void tcp_chr_disconnect(CharDriverState *chr) +{ + TCPCharDriver *s = chr->opaque; + + s->connected = 0; + if (s->listen_chan) { + s->listen_tag = g_io_add_watch(s->listen_chan, G_IO_IN, + tcp_chr_accept, chr); + } + remove_fd_in_watch(chr); + g_io_channel_unref(s->chan); + s->chan = NULL; + closesocket(s->fd); + s->fd = -1; + qemu_chr_be_event(chr, CHR_EVENT_CLOSED); +} + static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) { CharDriverState *chr = opaque; @@ -2469,16 +2522,7 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) size = tcp_chr_recv(chr, (void *)buf, len); if (size == 0) { /* connection closed */ - s->connected = 0; - if (s->listen_chan) { - s->listen_tag = g_io_add_watch(s->listen_chan, G_IO_IN, tcp_chr_accept, chr); - } - remove_fd_in_watch(chr); - g_io_channel_unref(s->chan); - s->chan = NULL; - closesocket(s->fd); - s->fd = -1; - qemu_chr_be_event(chr, CHR_EVENT_CLOSED); + tcp_chr_disconnect(chr); } else if (size > 0) { if (s->do_telnetopt) tcp_chr_process_IAC_bytes(chr, s, buf, &size); @@ -2489,6 +2533,24 @@ static gboolean tcp_chr_read(GIOChannel *chan, GIOCondition cond, void *opaque) return TRUE; } +static int tcp_chr_sync_read(CharDriverState *chr, const uint8_t *buf, int len) +{ + TCPCharDriver *s = chr->opaque; + int size; + + if (!s->connected) { + return 0; + } + + size = tcp_chr_recv(chr, (void *) buf, len); + if (size == 0) { + /* connection closed */ + tcp_chr_disconnect(chr); + } + + return size; +} + #ifndef _WIN32 CharDriverState *qemu_chr_open_eventfd(int eventfd) { @@ -2660,6 +2722,7 @@ static CharDriverState *qemu_chr_open_socket_fd(int fd, bool do_nodelay, chr->opaque = s; 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->chr_add_client = tcp_chr_add_client; -- 1.8.3.2