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Input processing:

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Input processing used to keep all data in one single input buffer, which
makes it hard to handle nested events as well as reading directly from the
socket into the application buffer without an extra copy.

Create a new iscsi_in_pdu structure where we store the header, and any data
for the recevied pdu and store them in a proper input queue.

Change the signature for all processing functions to tahe a iscsi_in_pdu
structure for the received pdu instead of just a pointer to a buffer.
This commit is contained in:
Ronnie Sahlberg
2010-12-11 15:15:51 +11:00
parent 8a6665a092
commit 1c024d6bc4
8 changed files with 172 additions and 148 deletions
Download Patch File Download Diff File Expand all files Collapse all files

150
lib/socket.c
View File

@@ -167,81 +167,85 @@ iscsi_which_events(struct iscsi_context *iscsi)
static int
iscsi_read_from_socket(struct iscsi_context *iscsi)
{
int available;
int size;
unsigned char *buf;
ssize_t count;
struct iscsi_in_pdu *in;
ssize_t data_size, count;
if (ioctl(iscsi->fd, FIONREAD, &available) != 0) {
iscsi_set_error(iscsi, "ioctl FIONREAD returned error : "
"%d", errno);
return -1;
}
if (available == 0) {
iscsi_set_error(iscsi, "no data readable in socket, "
"socket is closed");
return -1;
}
size = iscsi->insize - iscsi->inpos + available;
buf = malloc(size);
if (buf == NULL) {
iscsi_set_error(iscsi, "failed to allocate %d bytes for "
"input buffer", size);
return -1;
}
if (iscsi->insize > iscsi->inpos) {
memcpy(buf, iscsi->inbuf + iscsi->inpos,
iscsi->insize - iscsi->inpos);
iscsi->insize -= iscsi->inpos;
iscsi->inpos = 0;
}
count = read(iscsi->fd, buf + iscsi->insize, available);
if (count == -1) {
if (errno == EINTR) {
free(buf);
buf = NULL;
return 0;
if (iscsi->incoming == NULL) {
iscsi->incoming = malloc(sizeof(struct iscsi_in_pdu));
if (iscsi->incoming == NULL) {
iscsi_set_error(iscsi, "Out-of-memory: failed to malloc iscsi_in_pdu");
return -1;
}
iscsi_set_error(iscsi, "read from socket failed, "
bzero(iscsi->incoming, sizeof(struct iscsi_in_pdu));
}
in = iscsi->incoming;
/* first we must read the header, including any digests */
if (in->hdr_pos < ISCSI_HEADER_SIZE) {
count = read(iscsi->fd, &in->hdr[in->hdr_pos], ISCSI_HEADER_SIZE - in->hdr_pos);
if (count < 0) {
if (errno == EINTR) {
return 0;
}
iscsi_set_error(iscsi, "read from socket failed, "
"errno:%d", errno);
free(buf);
buf = NULL;
return -1;
}
free(iscsi->inbuf);
iscsi->inbuf = buf;
iscsi->insize += count;
while (1) {
if (iscsi->insize - iscsi->inpos < ISCSI_RAW_HEADER_SIZE) {
return 0;
}
count = iscsi_get_pdu_size(iscsi,
iscsi->inbuf + iscsi->inpos);
if (iscsi->insize + iscsi->inpos < count) {
return 0;
}
if (iscsi_process_pdu(iscsi, iscsi->inbuf + iscsi->inpos,
count) != 0) {
iscsi->inpos += count;
return -1;
}
iscsi->inpos += count;
if (iscsi->inpos == iscsi->insize) {
free(iscsi->inbuf);
iscsi->inbuf = NULL;
iscsi->insize = 0;
iscsi->inpos = 0;
if (count == 0) {
return 0;
}
if (iscsi->inpos > iscsi->insize) {
iscsi_set_error(iscsi, "inpos > insize. bug!");
in->hdr_pos += count;
}
if (in->hdr_pos < ISCSI_HEADER_SIZE) {
/* we dont have the full header yet, so return */
return 0;
}
data_size = iscsi_get_pdu_data_size(&in->hdr[0]);
if (data_size != 0) {
if (in->data == NULL) {
in->data = malloc(data_size);
if (in->data == NULL) {
iscsi_set_error(iscsi, "Out-of-memory: failed to malloc iscsi_in_pdu->data(%d)", (int)data_size);
return -1;
}
}
count = read(iscsi->fd, &in->data[in->data_pos], data_size - in->data_pos);
if (count < 0) {
if (errno == EINTR) {
return 0;
}
iscsi_set_error(iscsi, "read from socket failed, "
"errno:%d", errno);
return -1;
}
if (count == 0) {
return 0;
}
in->data_pos += count;
}
if (in->data_pos < data_size) {
return 0;
}
SLIST_ADD_END(&iscsi->inqueue, in);
iscsi->incoming = NULL;
while (iscsi->inqueue != NULL) {
struct iscsi_in_pdu *in = iscsi->inqueue;
if (iscsi_process_pdu(iscsi, in) != 0) {
return -1;
}
SLIST_REMOVE(&iscsi->inqueue, in);
iscsi_free_iscsi_in_pdu(in);
}
return 0;
}
@@ -353,3 +357,19 @@ iscsi_queue_pdu(struct iscsi_context *iscsi, struct iscsi_pdu *pdu)
return 0;
}
void
iscsi_free_iscsi_in_pdu(struct iscsi_in_pdu *in)
{
free(in->data);
free(in);
}
void
iscsi_free_iscsi_inqueue(struct iscsi_in_pdu *inqueue)
{
while (inqueue != NULL) {
struct iscsi_in_pdu *next = inqueue->next;
iscsi_free_iscsi_in_pdu(inqueue);
inqueue = next;
}
}