diff options
author | Andreas Schneider <asn@samba.org> | 2015-08-25 17:20:20 +0200 |
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committer | Andreas Schneider <asn@cryptomilk.org> | 2015-09-08 13:47:20 +0200 |
commit | 830e3dd14f363620d153e66e23978c4738c919f0 (patch) | |
tree | e3e1d3582d113a7fcd2d523c89da0ba16ccdf2f2 /lib/socket_wrapper | |
parent | 55432439e2b5947181b8185c4e21659068ca18be (diff) | |
download | samba-830e3dd14f363620d153e66e23978c4738c919f0.tar.gz |
swrap: Add environment variable to specify mtu size
Signed-off-by: Andreas Schneider <asn@samba.org>
Reviewed-by: Stefan Metzmacher <metze@samba.org>
Diffstat (limited to 'lib/socket_wrapper')
-rw-r--r-- | lib/socket_wrapper/socket_wrapper.c | 62 |
1 files changed, 50 insertions, 12 deletions
diff --git a/lib/socket_wrapper/socket_wrapper.c b/lib/socket_wrapper/socket_wrapper.c index 18622af27a0..01ab8d52d38 100644 --- a/lib/socket_wrapper/socket_wrapper.c +++ b/lib/socket_wrapper/socket_wrapper.c @@ -203,11 +203,12 @@ enum swrap_dbglvl_e { #define SOCKET_TYPE_CHAR_UDP_V6 'Y' /* - * Cut down to 1500 byte packets for stream sockets, - * which makes it easier to format PCAP capture files - * (as the caller will simply continue from here) + * Set the packet MTU to 1500 bytes for stream sockets to make it it easier to + * format PCAP capture files (as the caller will simply continue from here). */ -#define SOCKET_MAX_PACKET 1500 +#define SOCKET_WRAPPER_MTU_DEFAULT 1500 +#define SOCKET_WRAPPER_MTU_MIN 512 +#define SOCKET_WRAPPER_MTU_MAX 32768 #define SOCKET_MAX_SOCKETS 1024 @@ -912,6 +913,38 @@ static const char *socket_wrapper_dir(void) return s; } +static unsigned int socket_wrapper_mtu(void) +{ + static unsigned int max_mtu = 0; + unsigned int tmp; + const char *s; + char *endp; + + if (max_mtu != 0) { + return max_mtu; + } + + max_mtu = SOCKET_WRAPPER_MTU_DEFAULT; + + s = getenv("SOCKET_WRAPPER_MTU"); + if (s == NULL) { + goto done; + } + + tmp = strtol(s, &endp, 10); + if (s == endp) { + goto done; + } + + if (tmp < SOCKET_WRAPPER_MTU_MIN || tmp > SOCKET_WRAPPER_MTU_MAX) { + goto done; + } + max_mtu = tmp; + +done: + return max_mtu; +} + bool socket_wrapper_enabled(void) { const char *s = socket_wrapper_dir(); @@ -3743,7 +3776,9 @@ static ssize_t swrap_sendmsg_before(int fd, } switch (si->type) { - case SOCK_STREAM: + case SOCK_STREAM: { + unsigned long mtu; + if (!si->connected) { errno = ENOTCONN; return -1; @@ -3753,22 +3788,23 @@ static ssize_t swrap_sendmsg_before(int fd, break; } + mtu = socket_wrapper_mtu(); for (i = 0; i < (size_t)msg->msg_iovlen; i++) { size_t nlen; nlen = len + msg->msg_iov[i].iov_len; - if (nlen > SOCKET_MAX_PACKET) { + if (nlen > mtu) { break; } } msg->msg_iovlen = i; if (msg->msg_iovlen == 0) { *tmp_iov = msg->msg_iov[0]; - tmp_iov->iov_len = MIN(tmp_iov->iov_len, SOCKET_MAX_PACKET); + tmp_iov->iov_len = MIN(tmp_iov->iov_len, mtu); msg->msg_iov = tmp_iov; msg->msg_iovlen = 1; } break; - + } case SOCK_DGRAM: if (si->connected) { if (msg->msg_name) { @@ -3958,7 +3994,8 @@ static int swrap_recvmsg_before(int fd, (void)fd; /* unused */ switch (si->type) { - case SOCK_STREAM: + case SOCK_STREAM: { + unsigned int mtu; if (!si->connected) { errno = ENOTCONN; return -1; @@ -3968,22 +4005,23 @@ static int swrap_recvmsg_before(int fd, break; } + mtu = socket_wrapper_mtu(); for (i = 0; i < (size_t)msg->msg_iovlen; i++) { size_t nlen; nlen = len + msg->msg_iov[i].iov_len; - if (nlen > SOCKET_MAX_PACKET) { + if (nlen > mtu) { break; } } msg->msg_iovlen = i; if (msg->msg_iovlen == 0) { *tmp_iov = msg->msg_iov[0]; - tmp_iov->iov_len = MIN(tmp_iov->iov_len, SOCKET_MAX_PACKET); + tmp_iov->iov_len = MIN(tmp_iov->iov_len, mtu); msg->msg_iov = tmp_iov; msg->msg_iovlen = 1; } break; - + } case SOCK_DGRAM: if (msg->msg_name == NULL) { errno = EINVAL; |