bytemark/flexnbd-c
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Added write mode.

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This commit is contained in:
Matthew Bloch
2012-05-16 11:58:41 +01:00
parent b1aa942b3d
commit f688d416a5
1 changed files with 93 additions and 28 deletions
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121
flexnbd.c
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@@ -54,7 +54,8 @@ void syntax()
fprintf(stderr,
"Syntax: flexnbd serve <IP address> <port> <file> [ip addresses ...]\n"
" flexnbd read <IP address> <port> <offset> <length> > data\n"
" flexnbd write <IP address> <port> <offset> [length] < data\n"
" flexnbd write <IP address> <port> <offset> <length> < data\n"
" flexnbd write <IP address> <port> <offset> <data file>\n"
" flexnbd mirror <IP address> <port> <target IP> <target port>\n"
);
exit(1);
@@ -487,26 +488,37 @@ off64_t socket_nbd_read_hello(int fd)
return be64toh(init.size);
}
void fill_request(struct nbd_request *request, int type, int from, int len)
{
request->magic = htobe32(REQUEST_MAGIC);
request->type = htobe32(type);
((int*) request->handle)[0] = rand();
((int*) request->handle)[1] = rand();
request->from = htobe64(from);
request->len = htobe32(len);
}
void read_reply(int fd, struct nbd_request *request, struct nbd_reply *reply)
{
SERVER_ERROR_ON_FAILURE(readloop(fd, reply, sizeof(*reply)),
"Couldn't read reply");
if (be32toh(reply->magic) != REPLY_MAGIC)
SERVER_ERROR("Reply magic incorrect (%p)", reply->magic);
if (be32toh(reply->error) != 0)
SERVER_ERROR("Server replied with error %d", reply->error);
if (strncmp(request->handle, reply->handle, 8) != 0)
SERVER_ERROR("Did not reply with correct handle");
}
void socket_nbd_read(int fd, off64_t from, int len, int out_fd, void* out_buf)
{
struct nbd_request request;
struct nbd_reply reply;
request.magic = htobe32(REQUEST_MAGIC);
request.type = htobe32(REQUEST_READ);
((int*) request.handle)[0] = rand();
((int*) request.handle)[1] = rand();
request.from = htobe64(from);
request.len = htobe32(len);
fill_request(&request, REQUEST_READ, from, len);
SERVER_ERROR_ON_FAILURE(writeloop(fd, &request, sizeof(request)),
"Couldn't write request");
SERVER_ERROR_ON_FAILURE(readloop(fd, &reply, sizeof(reply)),
"Couldn't read reply");
if (be32toh(reply.magic) != REPLY_MAGIC)
SERVER_ERROR("Reply magic incorrect (%p)", reply.magic);
if (be32toh(reply.error) != 0)
SERVER_ERROR("Server replied with error %d", reply.error);
read_reply(fd, &request, &reply);
if (out_buf) {
SERVER_ERROR_ON_FAILURE(readloop(fd, out_buf, len),
@@ -520,14 +532,42 @@ void socket_nbd_read(int fd, off64_t from, int len, int out_fd, void* out_buf)
}
}
void socket_nbd_write(int fd, off64_t from, int len, int in_fd, void* in_buf)
{
struct nbd_request request;
struct nbd_reply reply;
fill_request(&request, REQUEST_WRITE, from, len);
SERVER_ERROR_ON_FAILURE(writeloop(fd, &request, sizeof(request)),
"Couldn't write request");
if (in_buf) {
SERVER_ERROR_ON_FAILURE(writeloop(fd, in_buf, len),
"Write failed");
}
else {
SERVER_ERROR_ON_FAILURE(
splice_via_pipe_loop(in_fd, fd, len),
"Splice failed"
);
}
read_reply(fd, &request, &reply);
}
#define CHECK_RANGE(error_type) { \
off64_t size = socket_nbd_read_hello(params->client); \
if (params->from < 0 || (params->from + params->len) >= size) \
SERVER_ERROR(error_type \
" request %d+%d is out of range given size %d", \
params->from, params->len, size\
); \
}
void do_read(struct mode_readwrite_params* params)
{
off64_t size;
params->client = socket_connect(&params->connect_to.generic);
size = socket_nbd_read_hello(params->client);
if (params->from < 0 || (params->from + params->len) >= size)
SERVER_ERROR("Read request %d+%d is out of range given size %d",
params->from, params->len, size);
CHECK_RANGE("read");
socket_nbd_read(params->client, params->from, params->len,
params->data_fd, NULL);
close(params->client);
@@ -536,6 +576,9 @@ void do_read(struct mode_readwrite_params* params)
void do_write(struct mode_readwrite_params* params)
{
params->client = socket_connect(&params->connect_to.generic);
CHECK_RANGE("write");
socket_nbd_write(params->client, params->from, params->len,
params->data_fd, NULL);
close(params->client);
}
@@ -653,11 +696,12 @@ void params_serve(
}
void params_readwrite(
int write_not_read,
struct mode_readwrite_params* out,
char* s_ip_address,
char* s_port,
char* s_from,
char* s_length
char* s_length_or_filename
)
{
if (s_ip_address == NULL)
@@ -666,20 +710,43 @@ void params_readwrite(
SERVER_ERROR("No port number supplied");
if (s_from == NULL)
SERVER_ERROR("No from supplied");
if (s_length == NULL)
if (s_length_or_filename == NULL)
SERVER_ERROR("No length supplied");
if (parse_ip_to_sockaddr(&out->connect_to.generic, s_ip_address) == 0)
SERVER_ERROR("Couldn't parse connection address '%s'");
SERVER_ERROR("Couldn't parse connection address '%s'",
s_ip_address);
out->connect_to.v4.sin_port = atoi(s_port);
if (out->connect_to.v4.sin_port < 0 || out->connect_to.v4.sin_port > 65535)
SERVER_ERROR("Port number must be >= 0 and <= 65535");
out->connect_to.v4.sin_port = htobe16(out->connect_to.v4.sin_port);
out->from = atol(s_from);
out->len = atol(s_length);
if (write_not_read) {
if (s_length_or_filename[0]-48 < 10) {
out->len = atol(s_length_or_filename);
out->data_fd = 0;
}
else {
out->data_fd = open(
s_length_or_filename, O_RDONLY);
SERVER_ERROR_ON_FAILURE(out->data_fd,
"Couldn't open %s", s_length_or_filename);
out->len = lseek64(out->data_fd, 0, SEEK_END);
SERVER_ERROR_ON_FAILURE(out->len,
"Couldn't find length of %s", s_length_or_filename);
SERVER_ERROR_ON_FAILURE(
lseek64(out->data_fd, 0, SEEK_SET),
"Couldn't rewind %s", s_length_or_filename
);
}
}
else {
out->len = atol(s_length_or_filename);
out->data_fd = 1;
}
}
void mode(char* mode, int argc, char **argv)
@@ -697,8 +764,7 @@ void mode(char* mode, int argc, char **argv)
}
else if (strcmp(mode, "read") == 0 ) {
if (argc == 4) {
params_readwrite(&params.readwrite, argv[0], argv[1], argv[2], argv[3]);
params.readwrite.data_fd = 1;
params_readwrite(0, &params.readwrite, argv[0], argv[1], argv[2], argv[3]);
do_read(&params.readwrite);
}
else {
@@ -707,8 +773,7 @@ void mode(char* mode, int argc, char **argv)
}
else if (strcmp(mode, "write") == 0 ) {
if (argc == 4) {
params_readwrite(&params.readwrite, argv[0], argv[1], argv[2], argv[3]);
params.readwrite.data_fd = 0;
params_readwrite(1, &params.readwrite, argv[0], argv[1], argv[2], argv[3]);
do_write(&params.readwrite);
}
else {