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|
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <poll.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "nfsmount.h"
#include "sunrpc.h"
/*
* The magic offset is needed here because RPC over TCP includes a
* field that RPC over UDP doesn't. Luvverly.
*/
static int rpc_do_reply(struct client *clnt, struct rpc *rpc, size_t off)
{
int ret;
if ((ret = read(clnt->sock,
((char *)rpc->reply) + off,
rpc->reply_len - off)) == -1) {
perror("read");
goto bail;
} else if (ret < sizeof(struct rpc_reply) - off) {
fprintf(stderr, "short read: %d < %zu\n", ret,
sizeof(struct rpc_reply) - off);
goto bail;
}
rpc->reply_len = ret + off;
if ((!off && !(ntohl(rpc->reply->hdr.frag_hdr) & LAST_FRAG)) ||
rpc->reply->hdr.udp.xid != rpc->call->hdr.udp.xid ||
rpc->reply->hdr.udp.msg_type != htonl(RPC_REPLY)) {
fprintf(stderr, "bad reply\n");
goto bail;
}
if (ntohl(rpc->reply->state) != REPLY_OK) {
fprintf(stderr, "rpc failed: %d\n", ntohl(rpc->reply->state));
goto bail;
}
ret = 0;
goto done;
bail:
ret = -1;
done:
return ret;
}
static void rpc_header(struct client *clnt, struct rpc *rpc)
{
(void)clnt;
rpc->call->hdr.frag_hdr = htonl(LAST_FRAG | (rpc->call_len - 4));
rpc->call->hdr.udp.xid = lrand48();
rpc->call->hdr.udp.msg_type = htonl(RPC_CALL);
rpc->call->rpc_vers = htonl(2);
}
static int rpc_call_tcp(struct client *clnt, struct rpc *rpc)
{
int ret;
rpc_header(clnt, rpc);
if ((ret = write(clnt->sock, rpc->call, rpc->call_len)) == -1) {
perror("write");
goto bail;
} else if (ret < rpc->call_len) {
fprintf(stderr, "short write: %d < %zu\n", ret, rpc->call_len);
goto bail;
}
ret = rpc_do_reply(clnt, rpc, 0);
goto done;
bail:
ret = -1;
done:
return ret;
}
static int rpc_call_udp(struct client *clnt, struct rpc *rpc)
{
#define NR_FDS 1
#define TIMEOUT_MS 3000
#define MAX_TRIES 100
#define UDP_HDR_OFF (sizeof(struct rpc_header) - sizeof(struct rpc_udp_header))
struct pollfd fds[NR_FDS];
int ret = -1;
int i;
rpc_header(clnt, rpc);
fds[0].fd = clnt->sock;
fds[0].events = POLLRDNORM;
rpc->call_len -= UDP_HDR_OFF;
for (i = 0; i < MAX_TRIES; i++) {
int timeout_ms = TIMEOUT_MS + (lrand48() % (TIMEOUT_MS / 2));
if ((ret = write(clnt->sock,
((char *)rpc->call) + UDP_HDR_OFF,
rpc->call_len)) == -1) {
perror("write");
goto bail;
} else if (ret < rpc->call_len) {
fprintf(stderr, "short write: %d < %zu\n", ret,
rpc->call_len);
goto bail;
}
for (; i < MAX_TRIES; i++) {
if ((ret = poll(fds, NR_FDS, timeout_ms)) == -1) {
perror("poll");
goto bail;
}
if (ret == 0) {
dprintf("Timeout #%d\n", i + 1);
break;
}
if ((ret = rpc_do_reply(clnt, rpc, UDP_HDR_OFF)) == 0) {
goto done;
} else {
dprintf("Failed on try #%d - retrying\n",
i + 1);
}
}
}
bail:
ret = -1;
done:
return ret;
}
struct client *tcp_client(uint32_t server, uint16_t port, uint32_t flags)
{
struct client *clnt = malloc(sizeof(*clnt));
struct sockaddr_in addr;
int sock;
if (clnt == NULL) {
perror("malloc");
goto bail;
}
memset(clnt, 0, sizeof(*clnt));
if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1) {
perror("socket");
goto bail;
}
if ((flags & CLI_RESVPORT) && bindresvport(sock, 0) == -1) {
perror("bindresvport");
goto bail;
}
clnt->sock = sock;
clnt->call_stub = rpc_call_tcp;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = server;
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
perror("connect");
goto bail;
}
goto done;
bail:
if (clnt) {
free(clnt);
clnt = NULL;
}
done:
return clnt;
}
struct client *udp_client(uint32_t server, uint16_t port, uint32_t flags)
{
struct client *clnt = malloc(sizeof(*clnt));
struct sockaddr_in addr;
int sock;
if (clnt == NULL) {
perror("malloc");
goto bail;
}
memset(clnt, 0, sizeof(*clnt));
if ((sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
perror("socket");
goto bail;
}
if ((flags & CLI_RESVPORT) && bindresvport(sock, 0) == -1) {
perror("bindresvport");
goto bail;
} else {
struct sockaddr_in me;
me.sin_family = AF_INET;
me.sin_port = 0;
me.sin_addr.s_addr = INADDR_ANY;
if (0 && bind(sock, (struct sockaddr *)&me, sizeof(me)) == -1) {
perror("bind");
goto bail;
}
}
clnt->sock = sock;
clnt->call_stub = rpc_call_udp;
addr.sin_family = AF_INET;
addr.sin_port = htons(port);
addr.sin_addr.s_addr = server;
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) == -1) {
perror("connect");
goto bail;
}
goto done;
bail:
if (clnt) {
free(clnt);
clnt = NULL;
}
done:
return clnt;
}
void client_free(struct client *c)
{
if (c->sock != -1)
close(c->sock);
free(c);
}
int rpc_call(struct client *client, struct rpc *rpc)
{
return client->call_stub(client, rpc);
}
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