Note: This patch is reformatted and is being resent as suggested by Sean
Also attached the patch file for convenience
From: Sreedhar Kodali <srkodali@xxxxxxxxxxxxxxxxxx>
Date: Thu Sep 18 11:33:21 2014 +0530
By default the R-Sockets pre-loading library intercepts all the
stream
and datagram sockets belonging to a launched program processes and
threads.
However, distributed application and database servers may require
fine
grained interception to ensure that only the processes which are
listening
for remote connections on the RDMA transport need to be enabled with
RDMA
while remaining can continue to use TCP as before. This allows
proper
communication happening between various server components locally.
A configuration file based mechanism is introduced to facilitate
this
fine grained interception mechanism. As part of preload
initialization,
the configuration file is scanned and an in-memory record store is
created
with all the entries found. When a request is made to intercept a
socket,
its attributes are cross checked with stored records to see whether
we
should proceed with rsocket switch over.
Note: Right now, the fine grained interception mechanism is enabled
only
for newly created sockets. Going forward, this can be extened to
select connections based on the specified host/IP addresses and
ports as well.
"preload_config" is the name of the configuration file which should
exist
in the default configuration location (usually the full path to this
configuration file is:
<install-root>/etc/rdma/rsocket/preload_config)
of an installed rsocket library.
The sample format for this configuration file is shown below:
@#
@# Sample config file for preloading in a program specific way
@#
@# Each line entry should have the following format:
@#
@# prog_name <space> dom_spec <space> type_spec <space> proto_spec
@#
@# where,
@#
@# prog_name - program or command name (string without spaces)
@# dom_spec - one or more socket domain strings separated by
commas
@# - format: {*|domain,[,domain,...]}
@# - '*' means any valid domain
@# - valid domains: inet/inet6/ib
@# type_spec - one or more socket type strings separated by commas
@# - format: {*|type[,type,...]}
@# - '*' means any valid type
@# - valid types: stream/dgram
@# proto_spec - one or more socket protocol strings separated by
commas
@# - format: {*|protocol[,protocol,...]}
@# - '*' means any valid protocol
@# - valid protocols: tcp/udp
@# <space> - one ore more tab or space characters
@#
@# Note:
@# Lines beginning with '#' character are treated as comments.
@# Comments at the end of an entry are allowed and should be
preceded
@# by '#' character.
@# Blank lines are ignored.
@
@progA inet stream tcp # intercept progA's internet stream sockets
@progB inet6 dgram udp # intercept progB's ipv6 datagram sockets
@progC * * * # intercept progC's sockets
Signed-off-by: Sreedhar Kodali <srkodali@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Pradeep Satyanarayana <pradeeps@xxxxxxxxxxxxxxxxxx>
---
diff --git a/src/preload.c b/src/preload.c
index fb2149b..b597616 100644
--- a/src/preload.c
+++ b/src/preload.c
@@ -50,6 +50,8 @@
#include <netinet/tcp.h>
#include <unistd.h>
#include <semaphore.h>
+#include <ctype.h>
+#include <stdlib.h>
#include <rdma/rdma_cma.h>
#include <rdma/rdma_verbs.h>
@@ -122,6 +124,217 @@ struct fd_info {
atomic_t refcnt;
};
+typedef struct {
+ char *name;
+ uint32_t domain;
+ uint32_t type;
+ uint32_t protocol;
+} config_entry_t;
+
+static config_entry_t *entryp;
+static int16_t nentries;
+static int16_t config_avail;
+extern char *program_invocation_short_name;
+
+/* scan preload configuration file and create
+ * in-memory config store
+ * should be called only once under lock
+ */
+static int scan_preload_config(void)
+{
+ FILE *fp;
+ char line[512];
+ char *lp, *cp, *str1, *str2;
+ char *token, *subtoken, *saveptr1, *saveptr2;
+ int i, j, ret = 0;
+
+ fp = fopen(RS_CONF_DIR "/preload_config", "r");
+ if (fp == NULL) {
+ return -1;
+ }
+
+ while ((lp = fgets(line, sizeof(line), fp)) != NULL) {
+
+ /* trim white space at the beginning of each line */
+ while (*lp != '\0') {
+ if (isspace(*lp)) {
+ lp++;
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ /* skip comment and blank lines */
+ if (*lp == '\0' || *lp == '#') {
+ continue;
+ }
+
+ /* trim comments and newlines at the end of each line */
+ if ((cp = strpbrk(lp, "#\n")) != NULL) {
+ *cp = '\0';
+ }
+
+ /* now allocate memory for new configuration entry */
+ entryp = (config_entry_t *) realloc(entryp, (nentries +
1) *
+ sizeof(config_entry_t));
+ if (!entryp) {
+ ret = -1;
+ goto scan_done;
+ }
+ memset(entryp + nentries, '\0', sizeof(config_entry_t));
+
+ /* tokenize the retrieved line and parse individual
fields */
+ for (i = 1, str1 = lp; ; i++, str1 = NULL) {
+ token = strtok_r(str1, " \t", &saveptr1);
+ if (token == NULL) {
+ break;
+ }
+
+ /* first field should contain program name */
+ if (i == 1) {
+ entryp[nentries].name = (char *)
malloc((strlen(token) + 1));
+ if (!entryp[nentries].name) {
+ ret = -1;
+ goto scan_done;
+ }
+ memcpy(entryp[nentries].name, token,
strlen(token) + 1);
+ continue;
+ }
+
+ /* second field onwards can contain multiple
entries
+ * separated by commas
+ */
+ for (j = 1, str2 = token; ; j++, str2 = NULL) {
+ subtoken = strtok_r(str2, ",",
&saveptr2);
+ if (subtoken == NULL) {
+ break;
+ }
+
+ /* second field is socket domain
+ * rsocket currently recognizes only
AF_INET, AF_INET6
+ * and AF_IB domains
+ * '*' implies all the valid domains
+ */
+ if (i == 2) {
+ if (*subtoken == '*') {
+ entryp[nentries].domain
|= (1 << AF_INET);
+ entryp[nentries].domain
|= (1 << AF_INET6);
+ entryp[nentries].domain
|= (1 << AF_IB);
+ break;
+ } else if (strcmp(subtoken,
"inet6") == 0) {
+ entryp[nentries].domain
|= (1 << AF_INET6);
+ } else if (strcmp(subtoken,
"inet") == 0) {
+ entryp[nentries].domain
|= (1 << AF_INET);
+ } else if (strcmp(subtoken,
"ib") == 0) {
+ entryp[nentries].domain
|= (1 << AF_IB);
+ }
+ continue;
+ }
+
+ /* third field is socket type
+ * rsocket currently recognizes only
SOCK_STREAM and
+ * SOCK_DGRAM types
+ * '*' implies all the valid types
+ */
+ if (i == 3) {
+ if (*subtoken == '*') {
+ entryp[nentries].type |=
(1 << SOCK_STREAM);
+ entryp[nentries].type |=
(1 << SOCK_DGRAM);
+ break;
+ } else if (strcmp(subtoken,
"stream") == 0) {
+ entryp[nentries].type |=
(1 << SOCK_STREAM);
+ } else if (strcmp(subtoken,
"dgram") == 0) {
+ entryp[nentries].type |=
(1 << SOCK_DGRAM);
+ }
+ continue;
+ }
+
+ /* fourth field is socket protocol
+ * rsocket currently recgonizes only
IPPROTO_TCP and
+ * IPPROTO_UDP protocols
+ * '*' implies all the valid protocols
+ */
+ if (i == 4) {
+ if (*subtoken == '*') {
+
entryp[nentries].protocol |= (1 << IPPROTO_TCP);
+
entryp[nentries].protocol |= (1 << IPPROTO_UDP);
+ break;
+ } else if (strcmp(subtoken,
"tcp") == 0) {
+
entryp[nentries].protocol |= (1 << IPPROTO_TCP);
+ } else if (strcmp(subtoken,
"udp") == 0) {
+
entryp[nentries].protocol |= (1 << IPPROTO_UDP);
+ }
+ continue;
+ }
+ }
+ }
+ nentries += 1;
+ }
+
+scan_done:
+ fclose(fp);
+ return ret;
+}
+
+/* free in-memory config store
+ * should be called only once during finalization
+ */
+static void free_preload_config(void)
+{
+ int i;
+
+ if (entryp) {
+ for (i = 0; i < nentries; i++) {
+ if (entryp[i].name) {
+ free(entryp[i].name);
+ }
+ }
+ free(entryp);
+ }
+
+ return;
+}
+
+/* check whether interception is required for this socket
+ * compares the provided attributes with that available in the
in-memory
+ * data store for the current process
+ * sets-up in-memory config store if it's already not done
+ */
+static int intercept_socket(int domain, int type, int protocol)
+{
+ int i;
+
+ /* locate the config entry */
+ for (i = 0; i < nentries; i++) {
+ if (strncmp(entryp[i].name,
program_invocation_short_name,
+ strlen(entryp[i].name)) == 0) {
+ break;
+ }
+ }
+ if (i == nentries) {
+ return 0;
+ }
+
+ /* match domain field */
+ if (!(entryp[i].domain & (1 << domain))) {
+ return 0;
+ }
+
+ /* match type field */
+ if (!(entryp[i].type & (1 << type))) {
+ return 0;
+ }
+
+ /* match protocol field only if protocol is specified */
+ if (protocol && !(entryp[i].protocol & (1 << protocol))) {
+ return 0;
+ }
+
+ /* entry matched */
+ return 1;
+}
+
static int fd_open(void)
{
struct fd_info *fdi;
@@ -308,6 +521,14 @@ static void init_preload(void)
rs.fcntl = dlsym(RTLD_DEFAULT, "rfcntl");
getenv_options();
+
+ if (scan_preload_config() == 0) {
+ config_avail = 1;
+ }
+ if (entryp) {
+ atexit(free_preload_config);
+ }
+
init = 1;
out:
pthread_mutex_unlock(&mut);
@@ -404,10 +625,15 @@ int socket(int domain, int type, int protocol)
static __thread int recursive;
int index, ret;
+ init_preload();
+
+ if (config_avail && intercept_socket(domain, type, protocol) ==
0) {
+ goto real;
+ }
+
if (recursive)
goto real;
- init_preload();
index = fd_open();
if (index < 0)
return index;
commit 89afd8cfcd1347f793ed7928f643213b6dbd4599
Author: Sreedhar Kodali <srkodali@xxxxxxxxxxxxxxxxxx>
Date: Thu Sep 18 11:33:21 2014 +0530
By default the R-Sockets pre-loading library intercepts all the stream
and datagram sockets belonging to a launched program processes and threads.
However, distributed application and database servers may require fine
grained interception to ensure that only the processes which are listening
for remote connections on the RDMA transport need to be enabled with RDMA
while remaining can continue to use TCP as before. This allows proper
communication happening between various server components locally.
A configuration file based mechanism is introduced to facilitate this
fine grained interception mechanism. As part of preload initialization,
the configuration file is scanned and an in-memory record store is created
with all the entries found. When a request is made to intercept a socket,
its attributes are cross checked with stored records to see whether we
should proceed with rsocket switch over.
Note: Right now, the fine grained interception mechanism is enabled only
for newly created sockets. Going forward, this can be extened to
select connections based on the specified host/IP addresses and
ports as well.
"preload_config" is the name of the configuration file which should exist
in the default configuration location (usually the full path to this
configuration file is: <install-root>/etc/rdma/rsocket/preload_config)
of an installed rsocket library.
The sample format for this configuration file is shown below:
@#
@# Sample config file for preloading in a program specific way
@#
@# Each line entry should have the following format:
@#
@# prog_name <space> dom_spec <space> type_spec <space> proto_spec
@#
@# where,
@#
@# prog_name - program or command name (string without spaces)
@# dom_spec - one or more socket domain strings separated by commas
@# - format: {*|domain,[,domain,...]}
@# - '*' means any valid domain
@# - valid domains: inet/inet6/ib
@# type_spec - one or more socket type strings separated by commas
@# - format: {*|type[,type,...]}
@# - '*' means any valid type
@# - valid types: stream/dgram
@# proto_spec - one or more socket protocol strings separated by commas
@# - format: {*|protocol[,protocol,...]}
@# - '*' means any valid protocol
@# - valid protocols: tcp/udp
@# <space> - one ore more tab or space characters
@#
@# Note:
@# Lines beginning with '#' character are treated as comments.
@# Comments at the end of an entry are allowed and should be preceded
@# by '#' character.
@# Blank lines are ignored.
@
@progA inet stream tcp # intercept progA's internet stream sockets
@progB inet6 dgram udp # intercept progB's ipv6 datagram sockets
@progC * * * # intercept progC's sockets
Signed-off-by: Sreedhar Kodali <srkodali@xxxxxxxxxxxxxxxxxx>
Reviewed-by: Pradeep Satyanarayana <pradeeps@xxxxxxxxxxxxxxxxxx>
---
diff --git a/src/preload.c b/src/preload.c
index fb2149b..b597616 100644
--- a/src/preload.c
+++ b/src/preload.c
@@ -50,6 +50,8 @@
#include <netinet/tcp.h>
#include <unistd.h>
#include <semaphore.h>
+#include <ctype.h>
+#include <stdlib.h>
#include <rdma/rdma_cma.h>
#include <rdma/rdma_verbs.h>
@@ -122,6 +124,217 @@ struct fd_info {
atomic_t refcnt;
};
+typedef struct {
+ char *name;
+ uint32_t domain;
+ uint32_t type;
+ uint32_t protocol;
+} config_entry_t;
+
+static config_entry_t *entryp;
+static int16_t nentries;
+static int16_t config_avail;
+extern char *program_invocation_short_name;
+
+/* scan preload configuration file and create
+ * in-memory config store
+ * should be called only once under lock
+ */
+static int scan_preload_config(void)
+{
+ FILE *fp;
+ char line[512];
+ char *lp, *cp, *str1, *str2;
+ char *token, *subtoken, *saveptr1, *saveptr2;
+ int i, j, ret = 0;
+
+ fp = fopen(RS_CONF_DIR "/preload_config", "r");
+ if (fp == NULL) {
+ return -1;
+ }
+
+ while ((lp = fgets(line, sizeof(line), fp)) != NULL) {
+
+ /* trim white space at the beginning of each line */
+ while (*lp != '\0') {
+ if (isspace(*lp)) {
+ lp++;
+ continue;
+ } else {
+ break;
+ }
+ }
+
+ /* skip comment and blank lines */
+ if (*lp == '\0' || *lp == '#') {
+ continue;
+ }
+
+ /* trim comments and newlines at the end of each line */
+ if ((cp = strpbrk(lp, "#\n")) != NULL) {
+ *cp = '\0';
+ }
+
+ /* now allocate memory for new configuration entry */
+ entryp = (config_entry_t *) realloc(entryp, (nentries + 1) *
+ sizeof(config_entry_t));
+ if (!entryp) {
+ ret = -1;
+ goto scan_done;
+ }
+ memset(entryp + nentries, '\0', sizeof(config_entry_t));
+
+ /* tokenize the retrieved line and parse individual fields */
+ for (i = 1, str1 = lp; ; i++, str1 = NULL) {
+ token = strtok_r(str1, " \t", &saveptr1);
+ if (token == NULL) {
+ break;
+ }
+
+ /* first field should contain program name */
+ if (i == 1) {
+ entryp[nentries].name = (char *) malloc((strlen(token) + 1));
+ if (!entryp[nentries].name) {
+ ret = -1;
+ goto scan_done;
+ }
+ memcpy(entryp[nentries].name, token, strlen(token) + 1);
+ continue;
+ }
+
+ /* second field onwards can contain multiple entries
+ * separated by commas
+ */
+ for (j = 1, str2 = token; ; j++, str2 = NULL) {
+ subtoken = strtok_r(str2, ",", &saveptr2);
+ if (subtoken == NULL) {
+ break;
+ }
+
+ /* second field is socket domain
+ * rsocket currently recognizes only AF_INET, AF_INET6
+ * and AF_IB domains
+ * '*' implies all the valid domains
+ */
+ if (i == 2) {
+ if (*subtoken == '*') {
+ entryp[nentries].domain |= (1 << AF_INET);
+ entryp[nentries].domain |= (1 << AF_INET6);
+ entryp[nentries].domain |= (1 << AF_IB);
+ break;
+ } else if (strcmp(subtoken, "inet6") == 0) {
+ entryp[nentries].domain |= (1 << AF_INET6);
+ } else if (strcmp(subtoken, "inet") == 0) {
+ entryp[nentries].domain |= (1 << AF_INET);
+ } else if (strcmp(subtoken, "ib") == 0) {
+ entryp[nentries].domain |= (1 << AF_IB);
+ }
+ continue;
+ }
+
+ /* third field is socket type
+ * rsocket currently recognizes only SOCK_STREAM and
+ * SOCK_DGRAM types
+ * '*' implies all the valid types
+ */
+ if (i == 3) {
+ if (*subtoken == '*') {
+ entryp[nentries].type |= (1 << SOCK_STREAM);
+ entryp[nentries].type |= (1 << SOCK_DGRAM);
+ break;
+ } else if (strcmp(subtoken, "stream") == 0) {
+ entryp[nentries].type |= (1 << SOCK_STREAM);
+ } else if (strcmp(subtoken, "dgram") == 0) {
+ entryp[nentries].type |= (1 << SOCK_DGRAM);
+ }
+ continue;
+ }
+
+ /* fourth field is socket protocol
+ * rsocket currently recgonizes only IPPROTO_TCP and
+ * IPPROTO_UDP protocols
+ * '*' implies all the valid protocols
+ */
+ if (i == 4) {
+ if (*subtoken == '*') {
+ entryp[nentries].protocol |= (1 << IPPROTO_TCP);
+ entryp[nentries].protocol |= (1 << IPPROTO_UDP);
+ break;
+ } else if (strcmp(subtoken, "tcp") == 0) {
+ entryp[nentries].protocol |= (1 << IPPROTO_TCP);
+ } else if (strcmp(subtoken, "udp") == 0) {
+ entryp[nentries].protocol |= (1 << IPPROTO_UDP);
+ }
+ continue;
+ }
+ }
+ }
+ nentries += 1;
+ }
+
+scan_done:
+ fclose(fp);
+ return ret;
+}
+
+/* free in-memory config store
+ * should be called only once during finalization
+ */
+static void free_preload_config(void)
+{
+ int i;
+
+ if (entryp) {
+ for (i = 0; i < nentries; i++) {
+ if (entryp[i].name) {
+ free(entryp[i].name);
+ }
+ }
+ free(entryp);
+ }
+
+ return;
+}
+
+/* check whether interception is required for this socket
+ * compares the provided attributes with that available in the in-memory
+ * data store for the current process
+ * sets-up in-memory config store if it's already not done
+ */
+static int intercept_socket(int domain, int type, int protocol)
+{
+ int i;
+
+ /* locate the config entry */
+ for (i = 0; i < nentries; i++) {
+ if (strncmp(entryp[i].name, program_invocation_short_name,
+ strlen(entryp[i].name)) == 0) {
+ break;
+ }
+ }
+ if (i == nentries) {
+ return 0;
+ }
+
+ /* match domain field */
+ if (!(entryp[i].domain & (1 << domain))) {
+ return 0;
+ }
+
+ /* match type field */
+ if (!(entryp[i].type & (1 << type))) {
+ return 0;
+ }
+
+ /* match protocol field only if protocol is specified */
+ if (protocol && !(entryp[i].protocol & (1 << protocol))) {
+ return 0;
+ }
+
+ /* entry matched */
+ return 1;
+}
+
static int fd_open(void)
{
struct fd_info *fdi;
@@ -308,6 +521,14 @@ static void init_preload(void)
rs.fcntl = dlsym(RTLD_DEFAULT, "rfcntl");
getenv_options();
+
+ if (scan_preload_config() == 0) {
+ config_avail = 1;
+ }
+ if (entryp) {
+ atexit(free_preload_config);
+ }
+
init = 1;
out:
pthread_mutex_unlock(&mut);
@@ -404,10 +625,15 @@ int socket(int domain, int type, int protocol)
static __thread int recursive;
int index, ret;
+ init_preload();
+
+ if (config_avail && intercept_socket(domain, type, protocol) == 0) {
+ goto real;
+ }
+
if (recursive)
goto real;
- init_preload();
index = fd_open();
if (index < 0)
return index;
