transports: Resize socket send buffer if needed
This was originally added in openbmc/pldm to make the socket send buffer
big enough to send a message if the message is longer than the current
send buffer size.
When you call set_sock_opt with buffer size X, given that X is within a
certain range, the send buffer is actually set to 2*X. get_sock_opt
returns the 2*X value, not X. So add in some helper functions.
Change-Id: I8ded9357db4268cd264cf0ecfb80479223106c09
Signed-off-by: Rashmica Gupta <rashmica@linux.ibm.com>
diff --git a/src/transport/af-mctp.c b/src/transport/af-mctp.c
index 5084f7d..2ba854e 100644
--- a/src/transport/af-mctp.c
+++ b/src/transport/af-mctp.c
@@ -4,9 +4,11 @@
#include "container-of.h"
#include "libpldm/pldm.h"
#include "libpldm/transport.h"
+#include "socket.h"
#include "transport.h"
#include <errno.h>
+#include <limits.h>
#include <linux/mctp.h>
#include <poll.h>
#include <stdlib.h>
@@ -21,6 +23,7 @@
struct pldm_transport transport;
int socket;
pldm_tid_t tid_eid_map[MCTP_MAX_NUM_EID];
+ struct pldm_socket_sndbuf socket_send_buf;
};
#define transport_to_af_mctp(ptr) \
@@ -119,6 +122,12 @@
addr.smctp_type = MCTP_MSG_TYPE_PLDM;
addr.smctp_tag = MCTP_TAG_OWNER;
+ if (req_msg_len > INT_MAX ||
+ pldm_socket_sndbuf_accomodate(&(af_mctp->socket_send_buf),
+ (int)req_msg_len)) {
+ return PLDM_REQUESTER_SEND_FAIL;
+ }
+
ssize_t rc = sendto(af_mctp->socket, pldm_req_msg, req_msg_len, 0,
(struct sockaddr *)&addr, sizeof(addr));
if (rc == -1) {
@@ -149,6 +158,14 @@
free(af_mctp);
return -1;
}
+
+ if (pldm_socket_sndbuf_init(&af_mctp->socket_send_buf,
+ af_mctp->socket)) {
+ close(af_mctp->socket);
+ free(af_mctp);
+ return -1;
+ }
+
*ctx = af_mctp;
return 0;
}
diff --git a/src/transport/mctp-demux.c b/src/transport/mctp-demux.c
index 466d33c..2518d93 100644
--- a/src/transport/mctp-demux.c
+++ b/src/transport/mctp-demux.c
@@ -4,9 +4,11 @@
#include "container-of.h"
#include "libpldm/pldm.h"
#include "libpldm/transport.h"
+#include "socket.h"
#include "transport.h"
#include <errno.h>
+#include <limits.h>
#include <poll.h>
#include <stdlib.h>
#include <string.h>
@@ -24,6 +26,7 @@
/* In the future this probably needs to move to a tid-eid-uuid/network
* id mapping for multi mctp networks */
pldm_tid_t tid_eid_map[MCTP_MAX_NUM_EID];
+ struct pldm_socket_sndbuf socket_send_buf;
};
#define transport_to_demux(ptr) \
@@ -181,6 +184,12 @@
msg.msg_iov = iov;
msg.msg_iovlen = sizeof(iov) / sizeof(iov[0]);
+ if (req_msg_len > INT_MAX ||
+ pldm_socket_sndbuf_accomodate(&(demux->socket_send_buf),
+ (int)req_msg_len)) {
+ return PLDM_REQUESTER_SEND_FAIL;
+ }
+
ssize_t rc = sendmsg(demux->socket, &msg, 0);
if (rc == -1) {
return PLDM_REQUESTER_SEND_FAIL;
@@ -211,6 +220,13 @@
free(demux);
return -1;
}
+
+ if (pldm_socket_sndbuf_init(&demux->socket_send_buf, demux->socket)) {
+ close(demux->socket);
+ free(demux);
+ return -1;
+ }
+
*ctx = demux;
return 0;
}
@@ -249,6 +265,13 @@
free(demux);
return NULL;
}
+
+ if (pldm_socket_sndbuf_init(&demux->socket_send_buf, demux->socket)) {
+ close(demux->socket);
+ free(demux);
+ return NULL;
+ }
+
return demux;
}
diff --git a/src/transport/meson.build b/src/transport/meson.build
index 1fcc06a..511b1c4 100644
--- a/src/transport/meson.build
+++ b/src/transport/meson.build
@@ -1,5 +1,6 @@
libpldm_sources += files(
'af-mctp.c',
'mctp-demux.c',
+ 'socket.c',
'transport.c'
)
diff --git a/src/transport/socket.c b/src/transport/socket.c
new file mode 100644
index 0000000..6c299a8
--- /dev/null
+++ b/src/transport/socket.c
@@ -0,0 +1,87 @@
+#include "socket.h"
+
+#include <errno.h>
+#include <limits.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/socket.h>
+
+int pldm_socket_sndbuf_init(struct pldm_socket_sndbuf *ctx, int socket)
+{
+ FILE *fp;
+ long max_buf_size;
+ char line[128];
+ char *endptr;
+
+ if (socket == -1) {
+ return -1;
+ }
+ ctx->socket = socket;
+
+ fp = fopen("/proc/sys/net/core/wmem_max", "r");
+ if (fp == NULL || fgets(line, sizeof(line), fp) == NULL) {
+ fclose(fp);
+ return -1;
+ }
+
+ errno = 0;
+ max_buf_size = strtol(line, &endptr, 10);
+ if (errno != 0 || endptr == line) {
+ fclose(fp);
+ return -1;
+ }
+
+ fclose(fp);
+
+ if (max_buf_size > INT_MAX) {
+ max_buf_size = INT_MAX;
+ }
+ ctx->max_size = (int)max_buf_size;
+
+ if (pldm_socket_sndbuf_get(ctx)) {
+ return -1;
+ }
+
+ return 0;
+}
+
+int pldm_socket_sndbuf_accomodate(struct pldm_socket_sndbuf *ctx, int msg_len)
+{
+ if (msg_len < ctx->size) {
+ return 0;
+ }
+ /* If message is bigger than the max size, don't return a failure. Set
+ * the buffer to the max size and see what happens. We don't know how
+ * much of the extra space the kernel actually uses so let it tell us if
+ * there wasn't enough space */
+ if (msg_len > ctx->max_size) {
+ msg_len = ctx->max_size;
+ }
+ if (ctx->size == ctx->max_size) {
+ return 0;
+ }
+ int rc = setsockopt(ctx->socket, SOL_SOCKET, SO_SNDBUF, &(msg_len),
+ sizeof(msg_len));
+ if (rc == -1) {
+ return -1;
+ }
+ ctx->size = msg_len;
+ return 0;
+}
+
+int pldm_socket_sndbuf_get(struct pldm_socket_sndbuf *ctx)
+{
+ /* size returned by getsockopt is the actual size of the buffer - twice
+ * the size of the value used by setsockopt. So for consistency, return
+ * half of the buffer size */
+ int buf_size;
+ socklen_t optlen = sizeof(buf_size);
+ int rc = getsockopt(ctx->socket, SOL_SOCKET, SO_SNDBUF, &(buf_size),
+ &optlen);
+ if (rc == -1) {
+ return -1;
+ }
+ ctx->size = buf_size / 2;
+ return 0;
+}
diff --git a/src/transport/socket.h b/src/transport/socket.h
new file mode 100644
index 0000000..17751ca
--- /dev/null
+++ b/src/transport/socket.h
@@ -0,0 +1,14 @@
+#ifndef LIBPLDM_SRC_TRANSPORT_SOCKET_H
+#define LIBPLDM_SRC_TRANSPORT_SOCKET_H
+
+struct pldm_socket_sndbuf {
+ int size;
+ int socket;
+ int max_size;
+};
+
+int pldm_socket_sndbuf_init(struct pldm_socket_sndbuf *ctx, int socket);
+int pldm_socket_sndbuf_accomodate(struct pldm_socket_sndbuf *ctx, int msg_len);
+int pldm_socket_sndbuf_get(struct pldm_socket_sndbuf *ctx);
+
+#endif // LIBPLDM_SRC_TRANSPORT_SOCKET_H