Merge branch 'selftests-updates-to-allow-single-instance-of-nettest-for-client-and-server'

David Ahern says:

====================
selftests: Updates to allow single instance of nettest for client and server

Update nettest to handle namespace change internally to allow a
single instance to run both client and server modes. Device validation
needs to be moved after the namespace change and a few run time
options need to be split to allow values for client and server.

v4
- really fix the memory leak with stdout/stderr buffers

v3
- send proper status in do_server for UDP sockets
- fix memory leak with stdout/stderr buffers
- new patch with separate option for address binding
- new patch to remove unnecessary newline

v2
- fix checkpath warnings
====================

Link: https://lore.kernel.org/r/20210114030949.54425-1-dsahern@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Jakub Kicinski
2021-01-14 16:26:54 -08:00
2 changed files with 606 additions and 381 deletions

File diff suppressed because it is too large Load Diff

View File

@@ -9,6 +9,7 @@
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <linux/tcp.h>
#include <arpa/inet.h>
#include <net/if.h>
@@ -17,6 +18,7 @@
#include <fcntl.h>
#include <libgen.h>
#include <limits.h>
#include <sched.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
@@ -34,6 +36,8 @@
#define DEFAULT_PORT 12345
#define NS_PREFIX "/run/netns/"
#ifndef MAX
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#endif
@@ -43,12 +47,15 @@
struct sock_args {
/* local address */
const char *local_addr_str;
const char *client_local_addr_str;
union {
struct in_addr in;
struct in6_addr in6;
} local_addr;
/* remote address */
const char *remote_addr_str;
union {
struct in_addr in;
struct in6_addr in6;
@@ -73,10 +80,16 @@ struct sock_args {
int use_setsockopt;
int use_cmsg;
const char *dev;
const char *server_dev;
int ifindex;
const char *clientns;
const char *serverns;
const char *password;
const char *client_pw;
/* prefix for MD5 password */
const char *md5_prefix_str;
union {
struct sockaddr_in v4;
struct sockaddr_in6 v6;
@@ -84,15 +97,19 @@ struct sock_args {
unsigned int prefix_len;
/* expected addresses and device index for connection */
const char *expected_dev;
const char *expected_server_dev;
int expected_ifindex;
/* local address */
const char *expected_laddr_str;
union {
struct in_addr in;
struct in6_addr in6;
} expected_laddr;
/* remote address */
const char *expected_raddr_str;
union {
struct in_addr in;
struct in6_addr in6;
@@ -186,7 +203,7 @@ static void log_address(const char *desc, struct sockaddr *sa)
if (sa->sa_family == AF_INET) {
struct sockaddr_in *s = (struct sockaddr_in *) sa;
log_msg("%s %s:%d",
log_msg("%s %s:%d\n",
desc,
inet_ntop(AF_INET, &s->sin_addr, addrstr,
sizeof(addrstr)),
@@ -195,18 +212,37 @@ static void log_address(const char *desc, struct sockaddr *sa)
} else if (sa->sa_family == AF_INET6) {
struct sockaddr_in6 *s6 = (struct sockaddr_in6 *) sa;
log_msg("%s [%s]:%d",
log_msg("%s [%s]:%d\n",
desc,
inet_ntop(AF_INET6, &s6->sin6_addr, addrstr,
sizeof(addrstr)),
ntohs(s6->sin6_port));
}
printf("\n");
fflush(stdout);
}
static int switch_ns(const char *ns)
{
char path[PATH_MAX];
int fd, ret;
if (geteuid())
log_error("warning: likely need root to set netns %s!\n", ns);
snprintf(path, sizeof(path), "%s%s", NS_PREFIX, ns);
fd = open(path, 0);
if (fd < 0) {
log_err_errno("Failed to open netns path; can not switch netns");
return 1;
}
ret = setns(fd, CLONE_NEWNET);
close(fd);
return ret;
}
static int tcp_md5sig(int sd, void *addr, socklen_t alen, struct sock_args *args)
{
int keylen = strlen(args->password);
@@ -259,13 +295,13 @@ static int tcp_md5_remote(int sd, struct sock_args *args)
switch (args->version) {
case AF_INET:
sin.sin_port = htons(args->port);
sin.sin_addr = args->remote_addr.in;
sin.sin_addr = args->md5_prefix.v4.sin_addr;
addr = &sin;
alen = sizeof(sin);
break;
case AF_INET6:
sin6.sin6_port = htons(args->port);
sin6.sin6_addr = args->remote_addr.in6;
sin6.sin6_addr = args->md5_prefix.v6.sin6_addr;
addr = &sin6;
alen = sizeof(sin6);
break;
@@ -522,6 +558,33 @@ static int str_to_uint(const char *str, int min, int max, unsigned int *value)
return -1;
}
static int resolve_devices(struct sock_args *args)
{
if (args->dev) {
args->ifindex = get_ifidx(args->dev);
if (args->ifindex < 0) {
log_error("Invalid device name\n");
return 1;
}
}
if (args->expected_dev) {
unsigned int tmp;
if (str_to_uint(args->expected_dev, 0, INT_MAX, &tmp) == 0) {
args->expected_ifindex = (int)tmp;
} else {
args->expected_ifindex = get_ifidx(args->expected_dev);
if (args->expected_ifindex < 0) {
fprintf(stderr, "Invalid expected device\n");
return 1;
}
}
}
return 0;
}
static int expected_addr_match(struct sockaddr *sa, void *expected,
const char *desc)
{
@@ -533,7 +596,7 @@ static int expected_addr_match(struct sockaddr *sa, void *expected,
struct in_addr *exp_in = (struct in_addr *) expected;
if (s->sin_addr.s_addr != exp_in->s_addr) {
log_error("%s address does not match expected %s",
log_error("%s address does not match expected %s\n",
desc,
inet_ntop(AF_INET, exp_in,
addrstr, sizeof(addrstr)));
@@ -544,14 +607,14 @@ static int expected_addr_match(struct sockaddr *sa, void *expected,
struct in6_addr *exp_in = (struct in6_addr *) expected;
if (memcmp(&s6->sin6_addr, exp_in, sizeof(*exp_in))) {
log_error("%s address does not match expected %s",
log_error("%s address does not match expected %s\n",
desc,
inet_ntop(AF_INET6, exp_in,
addrstr, sizeof(addrstr)));
rc = 1;
}
} else {
log_error("%s address does not match expected - unknown family",
log_error("%s address does not match expected - unknown family\n",
desc);
rc = 1;
}
@@ -599,6 +662,160 @@ static int show_sockstat(int sd, struct sock_args *args)
return rc;
}
enum addr_type {
ADDR_TYPE_LOCAL,
ADDR_TYPE_REMOTE,
ADDR_TYPE_MCAST,
ADDR_TYPE_EXPECTED_LOCAL,
ADDR_TYPE_EXPECTED_REMOTE,
ADDR_TYPE_MD5_PREFIX,
};
static int convert_addr(struct sock_args *args, const char *_str,
enum addr_type atype)
{
int pfx_len_max = args->version == AF_INET6 ? 128 : 32;
int family = args->version;
char *str, *dev, *sep;
struct in6_addr *in6;
struct in_addr *in;
const char *desc;
void *addr;
int rc = 0;
str = strdup(_str);
if (!str)
return -ENOMEM;
switch (atype) {
case ADDR_TYPE_LOCAL:
desc = "local";
addr = &args->local_addr;
break;
case ADDR_TYPE_REMOTE:
desc = "remote";
addr = &args->remote_addr;
break;
case ADDR_TYPE_MCAST:
desc = "mcast grp";
addr = &args->grp;
break;
case ADDR_TYPE_EXPECTED_LOCAL:
desc = "expected local";
addr = &args->expected_laddr;
break;
case ADDR_TYPE_EXPECTED_REMOTE:
desc = "expected remote";
addr = &args->expected_raddr;
break;
case ADDR_TYPE_MD5_PREFIX:
desc = "md5 prefix";
if (family == AF_INET) {
args->md5_prefix.v4.sin_family = AF_INET;
addr = &args->md5_prefix.v4.sin_addr;
} else if (family == AF_INET6) {
args->md5_prefix.v6.sin6_family = AF_INET6;
addr = &args->md5_prefix.v6.sin6_addr;
} else
return 1;
sep = strchr(str, '/');
if (sep) {
*sep = '\0';
sep++;
if (str_to_uint(sep, 1, pfx_len_max,
&args->prefix_len) != 0) {
fprintf(stderr, "Invalid port\n");
return 1;
}
} else {
args->prefix_len = 0;
}
break;
default:
log_error("unknown address type\n");
exit(1);
}
switch (family) {
case AF_INET:
in = (struct in_addr *) addr;
if (str) {
if (inet_pton(AF_INET, str, in) == 0) {
log_error("Invalid %s IP address\n", desc);
rc = -1;
goto out;
}
} else {
in->s_addr = htonl(INADDR_ANY);
}
break;
case AF_INET6:
dev = strchr(str, '%');
if (dev) {
*dev = '\0';
dev++;
}
in6 = (struct in6_addr *) addr;
if (str) {
if (inet_pton(AF_INET6, str, in6) == 0) {
log_error("Invalid %s IPv6 address\n", desc);
rc = -1;
goto out;
}
} else {
*in6 = in6addr_any;
}
if (dev) {
args->scope_id = get_ifidx(dev);
if (args->scope_id < 0) {
log_error("Invalid scope on %s IPv6 address\n",
desc);
rc = -1;
goto out;
}
}
break;
default:
log_error("Invalid address family\n");
}
out:
free(str);
return rc;
}
static int validate_addresses(struct sock_args *args)
{
if (args->local_addr_str &&
convert_addr(args, args->local_addr_str, ADDR_TYPE_LOCAL) < 0)
return 1;
if (args->remote_addr_str &&
convert_addr(args, args->remote_addr_str, ADDR_TYPE_REMOTE) < 0)
return 1;
if (args->md5_prefix_str &&
convert_addr(args, args->md5_prefix_str,
ADDR_TYPE_MD5_PREFIX) < 0)
return 1;
if (args->expected_laddr_str &&
convert_addr(args, args->expected_laddr_str,
ADDR_TYPE_EXPECTED_LOCAL))
return 1;
if (args->expected_raddr_str &&
convert_addr(args, args->expected_raddr_str,
ADDR_TYPE_EXPECTED_REMOTE))
return 1;
return 0;
}
static int get_index_from_cmsg(struct msghdr *m)
{
struct cmsghdr *cm;
@@ -1180,8 +1397,19 @@ err:
return -1;
}
static int do_server(struct sock_args *args)
static void ipc_write(int fd, int message)
{
/* Not in both_mode, so there's no process to signal */
if (fd < 0)
return;
if (write(fd, &message, sizeof(message)) < 0)
log_err_errno("Failed to send client status");
}
static int do_server(struct sock_args *args, int ipc_fd)
{
/* ipc_fd = -1 if no parent process to signal */
struct timeval timeout = { .tv_sec = prog_timeout }, *ptval = NULL;
unsigned char addr[sizeof(struct sockaddr_in6)] = {};
socklen_t alen = sizeof(addr);
@@ -1190,6 +1418,20 @@ static int do_server(struct sock_args *args)
fd_set rfds;
int rc;
if (args->serverns) {
if (switch_ns(args->serverns)) {
log_error("Could not set server netns to %s\n",
args->serverns);
goto err_exit;
}
log_msg("Switched server netns\n");
}
args->dev = args->server_dev;
args->expected_dev = args->expected_server_dev;
if (resolve_devices(args) || validate_addresses(args))
goto err_exit;
if (prog_timeout)
ptval = &timeout;
@@ -1199,14 +1441,16 @@ static int do_server(struct sock_args *args)
lsd = lsock_init(args);
if (lsd < 0)
return 1;
goto err_exit;
if (args->bind_test_only) {
close(lsd);
ipc_write(ipc_fd, 1);
return 0;
}
if (args->type != SOCK_STREAM) {
ipc_write(ipc_fd, 1);
rc = msg_loop(0, lsd, (void *) addr, alen, args);
close(lsd);
return rc;
@@ -1214,11 +1458,11 @@ static int do_server(struct sock_args *args)
if (args->password && tcp_md5_remote(lsd, args)) {
close(lsd);
return 1;
goto err_exit;
}
ipc_write(ipc_fd, 1);
while (1) {
log_msg("\n");
log_msg("waiting for client connection.\n");
FD_ZERO(&rfds);
FD_SET(lsd, &rfds);
@@ -1264,6 +1508,9 @@ static int do_server(struct sock_args *args)
close(lsd);
return rc;
err_exit:
ipc_write(ipc_fd, 0);
return 1;
}
static int wait_for_connect(int sd)
@@ -1375,6 +1622,26 @@ static int do_client(struct sock_args *args)
return 1;
}
if (args->clientns) {
if (switch_ns(args->clientns)) {
log_error("Could not set client netns to %s\n",
args->clientns);
return 1;
}
log_msg("Switched client netns\n");
}
args->local_addr_str = args->client_local_addr_str;
if (resolve_devices(args) || validate_addresses(args))
return 1;
if ((args->use_setsockopt || args->use_cmsg) && !args->ifindex) {
fprintf(stderr, "Device binding not specified\n");
return 1;
}
if (args->use_setsockopt || args->use_cmsg)
args->dev = NULL;
switch (args->version) {
case AF_INET:
sin.sin_port = htons(args->port);
@@ -1394,6 +1661,8 @@ static int do_client(struct sock_args *args)
break;
}
args->password = args->client_pw;
if (args->has_grp)
sd = msock_client(args);
else
@@ -1419,132 +1688,6 @@ out:
return rc;
}
enum addr_type {
ADDR_TYPE_LOCAL,
ADDR_TYPE_REMOTE,
ADDR_TYPE_MCAST,
ADDR_TYPE_EXPECTED_LOCAL,
ADDR_TYPE_EXPECTED_REMOTE,
ADDR_TYPE_MD5_PREFIX,
};
static int convert_addr(struct sock_args *args, const char *_str,
enum addr_type atype)
{
int pfx_len_max = args->version == AF_INET6 ? 128 : 32;
int family = args->version;
char *str, *dev, *sep;
struct in6_addr *in6;
struct in_addr *in;
const char *desc;
void *addr;
int rc = 0;
str = strdup(_str);
if (!str)
return -ENOMEM;
switch (atype) {
case ADDR_TYPE_LOCAL:
desc = "local";
addr = &args->local_addr;
break;
case ADDR_TYPE_REMOTE:
desc = "remote";
addr = &args->remote_addr;
break;
case ADDR_TYPE_MCAST:
desc = "mcast grp";
addr = &args->grp;
break;
case ADDR_TYPE_EXPECTED_LOCAL:
desc = "expected local";
addr = &args->expected_laddr;
break;
case ADDR_TYPE_EXPECTED_REMOTE:
desc = "expected remote";
addr = &args->expected_raddr;
break;
case ADDR_TYPE_MD5_PREFIX:
desc = "md5 prefix";
if (family == AF_INET) {
args->md5_prefix.v4.sin_family = AF_INET;
addr = &args->md5_prefix.v4.sin_addr;
} else if (family == AF_INET6) {
args->md5_prefix.v6.sin6_family = AF_INET6;
addr = &args->md5_prefix.v6.sin6_addr;
} else
return 1;
sep = strchr(str, '/');
if (sep) {
*sep = '\0';
sep++;
if (str_to_uint(sep, 1, pfx_len_max,
&args->prefix_len) != 0) {
fprintf(stderr, "Invalid port\n");
return 1;
}
} else {
args->prefix_len = pfx_len_max;
}
break;
default:
log_error("unknown address type");
exit(1);
}
switch (family) {
case AF_INET:
in = (struct in_addr *) addr;
if (str) {
if (inet_pton(AF_INET, str, in) == 0) {
log_error("Invalid %s IP address\n", desc);
rc = -1;
goto out;
}
} else {
in->s_addr = htonl(INADDR_ANY);
}
break;
case AF_INET6:
dev = strchr(str, '%');
if (dev) {
*dev = '\0';
dev++;
}
in6 = (struct in6_addr *) addr;
if (str) {
if (inet_pton(AF_INET6, str, in6) == 0) {
log_error("Invalid %s IPv6 address\n", desc);
rc = -1;
goto out;
}
} else {
*in6 = in6addr_any;
}
if (dev) {
args->scope_id = get_ifidx(dev);
if (args->scope_id < 0) {
log_error("Invalid scope on %s IPv6 address\n",
desc);
rc = -1;
goto out;
}
}
break;
default:
log_error("Invalid address family\n");
}
out:
free(str);
return rc;
}
static char *random_msg(int len)
{
int i, n = 0, olen = len + 1;
@@ -1568,7 +1711,68 @@ static char *random_msg(int len)
return m;
}
#define GETOPT_STR "sr:l:p:t:g:P:DRn:M:m:d:SCi6L:0:1:2:Fbq"
static int ipc_child(int fd, struct sock_args *args)
{
char *outbuf, *errbuf;
int rc = 1;
outbuf = malloc(4096);
errbuf = malloc(4096);
if (!outbuf || !errbuf) {
fprintf(stderr, "server: Failed to allocate buffers for stdout and stderr\n");
goto out;
}
setbuffer(stdout, outbuf, 4096);
setbuffer(stderr, errbuf, 4096);
server_mode = 1; /* to tell log_msg in case we are in both_mode */
/* when running in both mode, address validation applies
* solely to client side
*/
args->has_expected_laddr = 0;
args->has_expected_raddr = 0;
rc = do_server(args, fd);
out:
free(outbuf);
free(errbuf);
return rc;
}
static int ipc_parent(int cpid, int fd, struct sock_args *args)
{
int client_status;
int status;
int buf;
/* do the client-side function here in the parent process,
* waiting to be told when to continue
*/
if (read(fd, &buf, sizeof(buf)) <= 0) {
log_err_errno("Failed to read IPC status from status");
return 1;
}
if (!buf) {
log_error("Server failed; can not continue\n");
return 1;
}
log_msg("Server is ready\n");
client_status = do_client(args);
log_msg("parent is done!\n");
if (kill(cpid, 0) == 0)
kill(cpid, SIGKILL);
wait(&status);
return client_status;
}
#define GETOPT_STR "sr:l:c:p:t:g:P:DRn:M:X:m:d:I:BN:O:SCi6L:0:1:2:3:Fbq"
static void print_usage(char *prog)
{
@@ -1582,13 +1786,18 @@ static void print_usage(char *prog)
" -t timeout seconds (default: none)\n"
"\n"
"Optional:\n"
" -B do both client and server via fork and IPC\n"
" -N ns set client to network namespace ns (requires root)\n"
" -O ns set server to network namespace ns (requires root)\n"
" -F Restart server loop\n"
" -6 IPv6 (default is IPv4)\n"
" -P proto protocol for socket: icmp, ospf (default: none)\n"
" -D|R datagram (D) / raw (R) socket (default stream)\n"
" -l addr local address to bind to\n"
" -l addr local address to bind to in server mode\n"
" -c addr local address to bind to in client mode\n"
"\n"
" -d dev bind socket to given device name\n"
" -I dev bind socket to given device name - server mode\n"
" -S use setsockopt (IP_UNICAST_IF or IP_MULTICAST_IF)\n"
" to set device binding\n"
" -C use cmsg and IP_PKTINFO to specify device binding\n"
@@ -1597,6 +1806,7 @@ static void print_usage(char *prog)
" -n num number of times to send message\n"
"\n"
" -M password use MD5 sum protection\n"
" -X password MD5 password for client mode\n"
" -m prefix/len prefix and length to use for MD5 key\n"
" -g grp multicast group (e.g., 239.1.1.1)\n"
" -i interactive mode (default is echo and terminate)\n"
@@ -1604,6 +1814,7 @@ static void print_usage(char *prog)
" -0 addr Expected local address\n"
" -1 addr Expected remote address\n"
" -2 dev Expected device name (or index) to receive packet\n"
" -3 dev Expected device name (or index) to receive packets - server mode\n"
"\n"
" -b Bind test only.\n"
" -q Be quiet. Run test without printing anything.\n"
@@ -1618,8 +1829,11 @@ int main(int argc, char *argv[])
.port = DEFAULT_PORT,
};
struct protoent *pe;
int both_mode = 0;
unsigned int tmp;
int forever = 0;
int fd[2];
int cpid;
/* process inputs */
extern char *optarg;
@@ -1631,6 +1845,9 @@ int main(int argc, char *argv[])
while ((rc = getopt(argc, argv, GETOPT_STR)) != -1) {
switch (rc) {
case 'B':
both_mode = 1;
break;
case 's':
server_mode = 1;
break;
@@ -1639,13 +1856,15 @@ int main(int argc, char *argv[])
break;
case 'l':
args.has_local_ip = 1;
if (convert_addr(&args, optarg, ADDR_TYPE_LOCAL) < 0)
return 1;
args.local_addr_str = optarg;
break;
case 'r':
args.has_remote_ip = 1;
if (convert_addr(&args, optarg, ADDR_TYPE_REMOTE) < 0)
return 1;
args.remote_addr_str = optarg;
break;
case 'c':
args.has_local_ip = 1;
args.client_local_addr_str = optarg;
break;
case 'p':
if (str_to_uint(optarg, 1, 65535, &tmp) != 0) {
@@ -1685,15 +1904,23 @@ int main(int argc, char *argv[])
case 'n':
iter = atoi(optarg);
break;
case 'N':
args.clientns = optarg;
break;
case 'O':
args.serverns = optarg;
break;
case 'L':
msg = random_msg(atoi(optarg));
break;
case 'M':
args.password = optarg;
break;
case 'X':
args.client_pw = optarg;
break;
case 'm':
if (convert_addr(&args, optarg, ADDR_TYPE_MD5_PREFIX) < 0)
return 1;
args.md5_prefix_str = optarg;
break;
case 'S':
args.use_setsockopt = 1;
@@ -1703,11 +1930,9 @@ int main(int argc, char *argv[])
break;
case 'd':
args.dev = optarg;
args.ifindex = get_ifidx(optarg);
if (args.ifindex < 0) {
fprintf(stderr, "Invalid device name\n");
return 1;
}
break;
case 'I':
args.server_dev = optarg;
break;
case 'i':
interactive = 1;
@@ -1726,28 +1951,17 @@ int main(int argc, char *argv[])
break;
case '0':
args.has_expected_laddr = 1;
if (convert_addr(&args, optarg,
ADDR_TYPE_EXPECTED_LOCAL))
return 1;
args.expected_laddr_str = optarg;
break;
case '1':
args.has_expected_raddr = 1;
if (convert_addr(&args, optarg,
ADDR_TYPE_EXPECTED_REMOTE))
return 1;
args.expected_raddr_str = optarg;
break;
case '2':
if (str_to_uint(optarg, 0, INT_MAX, &tmp) == 0) {
args.expected_ifindex = (int)tmp;
} else {
args.expected_ifindex = get_ifidx(optarg);
if (args.expected_ifindex < 0) {
fprintf(stderr,
"Invalid expected device\n");
return 1;
}
}
args.expected_dev = optarg;
break;
case '3':
args.expected_server_dev = optarg;
break;
case 'q':
quiet = 1;
@@ -1759,23 +1973,17 @@ int main(int argc, char *argv[])
}
if (args.password &&
((!args.has_remote_ip && !args.prefix_len) || args.type != SOCK_STREAM)) {
((!args.has_remote_ip && !args.md5_prefix_str) ||
args.type != SOCK_STREAM)) {
log_error("MD5 passwords apply to TCP only and require a remote ip for the password\n");
return 1;
}
if (args.prefix_len && !args.password) {
if (args.md5_prefix_str && !args.password) {
log_error("Prefix range for MD5 protection specified without a password\n");
return 1;
}
if ((args.use_setsockopt || args.use_cmsg) && !args.ifindex) {
fprintf(stderr, "Device binding not specified\n");
return 1;
}
if (args.use_setsockopt || args.use_cmsg)
args.dev = NULL;
if (iter == 0) {
fprintf(stderr, "Invalid number of messages to send\n");
return 1;
@@ -1792,7 +2000,7 @@ int main(int argc, char *argv[])
return 1;
}
if (!server_mode && !args.has_grp &&
if ((both_mode || !server_mode) && !args.has_grp &&
!args.has_remote_ip && !args.has_local_ip) {
fprintf(stderr,
"Local (server mode) or remote IP (client IP) required\n");
@@ -1804,9 +2012,26 @@ int main(int argc, char *argv[])
msg = NULL;
}
if (both_mode) {
if (pipe(fd) < 0) {
perror("pipe");
exit(1);
}
cpid = fork();
if (cpid < 0) {
perror("fork");
exit(1);
}
if (cpid)
return ipc_parent(cpid, fd[0], &args);
return ipc_child(fd[1], &args);
}
if (server_mode) {
do {
rc = do_server(&args);
rc = do_server(&args, -1);
} while (forever);
return rc;