git/pkt-line.c
Elijah Newren 5e3f94dfe3 treewide: remove cache.h inclusion due to previous changes
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2023-04-24 12:47:33 -07:00

681 lines
16 KiB
C

#include "git-compat-util.h"
#include "copy.h"
#include "pkt-line.h"
#include "gettext.h"
#include "hex.h"
#include "run-command.h"
#include "trace.h"
#include "wrapper.h"
#include "write-or-die.h"
char packet_buffer[LARGE_PACKET_MAX];
static const char *packet_trace_prefix = "git";
static struct trace_key trace_packet = TRACE_KEY_INIT(PACKET);
static struct trace_key trace_pack = TRACE_KEY_INIT(PACKFILE);
void packet_trace_identity(const char *prog)
{
packet_trace_prefix = xstrdup(prog);
}
static const char *get_trace_prefix(void)
{
return in_async() ? "sideband" : packet_trace_prefix;
}
static int packet_trace_pack(const char *buf, unsigned int len, int sideband)
{
if (!sideband) {
trace_verbatim(&trace_pack, buf, len);
return 1;
} else if (len && *buf == '\1') {
trace_verbatim(&trace_pack, buf + 1, len - 1);
return 1;
} else {
/* it's another non-pack sideband */
return 0;
}
}
static void packet_trace(const char *buf, unsigned int len, int write)
{
int i;
struct strbuf out;
static int in_pack, sideband;
if (!trace_want(&trace_packet) && !trace_want(&trace_pack))
return;
if (in_pack) {
if (packet_trace_pack(buf, len, sideband))
return;
} else if (starts_with(buf, "PACK") || starts_with(buf, "\1PACK")) {
in_pack = 1;
sideband = *buf == '\1';
packet_trace_pack(buf, len, sideband);
/*
* Make a note in the human-readable trace that the pack data
* started.
*/
buf = "PACK ...";
len = strlen(buf);
}
if (!trace_want(&trace_packet))
return;
/* +32 is just a guess for header + quoting */
strbuf_init(&out, len+32);
strbuf_addf(&out, "packet: %12s%c ",
get_trace_prefix(), write ? '>' : '<');
/* XXX we should really handle printable utf8 */
for (i = 0; i < len; i++) {
/* suppress newlines */
if (buf[i] == '\n')
continue;
if (buf[i] >= 0x20 && buf[i] <= 0x7e)
strbuf_addch(&out, buf[i]);
else
strbuf_addf(&out, "\\%o", buf[i]);
}
strbuf_addch(&out, '\n');
trace_strbuf(&trace_packet, &out);
strbuf_release(&out);
}
/*
* If we buffered things up above (we don't, but we should),
* we'd flush it here
*/
void packet_flush(int fd)
{
packet_trace("0000", 4, 1);
if (write_in_full(fd, "0000", 4) < 0)
die_errno(_("unable to write flush packet"));
}
void packet_delim(int fd)
{
packet_trace("0001", 4, 1);
if (write_in_full(fd, "0001", 4) < 0)
die_errno(_("unable to write delim packet"));
}
void packet_response_end(int fd)
{
packet_trace("0002", 4, 1);
if (write_in_full(fd, "0002", 4) < 0)
die_errno(_("unable to write response end packet"));
}
int packet_flush_gently(int fd)
{
packet_trace("0000", 4, 1);
if (write_in_full(fd, "0000", 4) < 0)
return error(_("flush packet write failed"));
return 0;
}
void packet_buf_flush(struct strbuf *buf)
{
packet_trace("0000", 4, 1);
strbuf_add(buf, "0000", 4);
}
void packet_buf_delim(struct strbuf *buf)
{
packet_trace("0001", 4, 1);
strbuf_add(buf, "0001", 4);
}
void set_packet_header(char *buf, int size)
{
static char hexchar[] = "0123456789abcdef";
#define hex(a) (hexchar[(a) & 15])
buf[0] = hex(size >> 12);
buf[1] = hex(size >> 8);
buf[2] = hex(size >> 4);
buf[3] = hex(size);
#undef hex
}
static void format_packet(struct strbuf *out, const char *prefix,
const char *fmt, va_list args)
{
size_t orig_len, n;
orig_len = out->len;
strbuf_addstr(out, "0000");
strbuf_addstr(out, prefix);
strbuf_vaddf(out, fmt, args);
n = out->len - orig_len;
if (n > LARGE_PACKET_MAX)
die(_("protocol error: impossibly long line"));
set_packet_header(&out->buf[orig_len], n);
packet_trace(out->buf + orig_len + 4, n - 4, 1);
}
static int packet_write_fmt_1(int fd, int gently, const char *prefix,
const char *fmt, va_list args)
{
static struct strbuf buf = STRBUF_INIT;
strbuf_reset(&buf);
format_packet(&buf, prefix, fmt, args);
if (write_in_full(fd, buf.buf, buf.len) < 0) {
if (!gently) {
check_pipe(errno);
die_errno(_("packet write with format failed"));
}
return error(_("packet write with format failed"));
}
return 0;
}
void packet_write_fmt(int fd, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
packet_write_fmt_1(fd, 0, "", fmt, args);
va_end(args);
}
int packet_write_fmt_gently(int fd, const char *fmt, ...)
{
int status;
va_list args;
va_start(args, fmt);
status = packet_write_fmt_1(fd, 1, "", fmt, args);
va_end(args);
return status;
}
static int do_packet_write(const int fd_out, const char *buf, size_t size,
struct strbuf *err)
{
char header[4];
size_t packet_size;
if (size > LARGE_PACKET_DATA_MAX) {
strbuf_addstr(err, _("packet write failed - data exceeds max packet size"));
return -1;
}
packet_trace(buf, size, 1);
packet_size = size + 4;
set_packet_header(header, packet_size);
/*
* Write the header and the buffer in 2 parts so that we do
* not need to allocate a buffer or rely on a static buffer.
* This also avoids putting a large buffer on the stack which
* might have multi-threading issues.
*/
if (write_in_full(fd_out, header, 4) < 0 ||
write_in_full(fd_out, buf, size) < 0) {
strbuf_addf(err, _("packet write failed: %s"), strerror(errno));
return -1;
}
return 0;
}
static int packet_write_gently(const int fd_out, const char *buf, size_t size)
{
struct strbuf err = STRBUF_INIT;
if (do_packet_write(fd_out, buf, size, &err)) {
error("%s", err.buf);
strbuf_release(&err);
return -1;
}
return 0;
}
void packet_write(int fd_out, const char *buf, size_t size)
{
struct strbuf err = STRBUF_INIT;
if (do_packet_write(fd_out, buf, size, &err))
die("%s", err.buf);
}
void packet_fwrite(FILE *f, const char *buf, size_t size)
{
size_t packet_size;
char header[4];
if (size > LARGE_PACKET_DATA_MAX)
die(_("packet write failed - data exceeds max packet size"));
packet_trace(buf, size, 1);
packet_size = size + 4;
set_packet_header(header, packet_size);
fwrite_or_die(f, header, 4);
fwrite_or_die(f, buf, size);
}
void packet_fwrite_fmt(FILE *fh, const char *fmt, ...)
{
static struct strbuf buf = STRBUF_INIT;
va_list args;
strbuf_reset(&buf);
va_start(args, fmt);
format_packet(&buf, "", fmt, args);
va_end(args);
fwrite_or_die(fh, buf.buf, buf.len);
}
void packet_fflush(FILE *f)
{
packet_trace("0000", 4, 1);
fwrite_or_die(f, "0000", 4);
fflush_or_die(f);
}
void packet_buf_write(struct strbuf *buf, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
format_packet(buf, "", fmt, args);
va_end(args);
}
int write_packetized_from_fd_no_flush(int fd_in, int fd_out)
{
char *buf = xmalloc(LARGE_PACKET_DATA_MAX);
int err = 0;
ssize_t bytes_to_write;
while (!err) {
bytes_to_write = xread(fd_in, buf, LARGE_PACKET_DATA_MAX);
if (bytes_to_write < 0) {
free(buf);
return COPY_READ_ERROR;
}
if (bytes_to_write == 0)
break;
err = packet_write_gently(fd_out, buf, bytes_to_write);
}
free(buf);
return err;
}
int write_packetized_from_buf_no_flush_count(const char *src_in, size_t len,
int fd_out, int *packet_counter)
{
int err = 0;
size_t bytes_written = 0;
size_t bytes_to_write;
while (!err) {
if ((len - bytes_written) > LARGE_PACKET_DATA_MAX)
bytes_to_write = LARGE_PACKET_DATA_MAX;
else
bytes_to_write = len - bytes_written;
if (bytes_to_write == 0)
break;
err = packet_write_gently(fd_out, src_in + bytes_written, bytes_to_write);
bytes_written += bytes_to_write;
if (packet_counter)
(*packet_counter)++;
}
return err;
}
static int get_packet_data(int fd, char **src_buf, size_t *src_size,
void *dst, unsigned size, int options)
{
ssize_t ret;
if (fd >= 0 && src_buf && *src_buf)
BUG("multiple sources given to packet_read");
/* Read up to "size" bytes from our source, whatever it is. */
if (src_buf && *src_buf) {
ret = size < *src_size ? size : *src_size;
memcpy(dst, *src_buf, ret);
*src_buf += ret;
*src_size -= ret;
} else {
ret = read_in_full(fd, dst, size);
if (ret < 0) {
if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
return error_errno(_("read error"));
die_errno(_("read error"));
}
}
/* And complain if we didn't get enough bytes to satisfy the read. */
if (ret != size) {
if (options & PACKET_READ_GENTLE_ON_EOF)
return -1;
if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
return error(_("the remote end hung up unexpectedly"));
die(_("the remote end hung up unexpectedly"));
}
return ret;
}
int packet_length(const char lenbuf_hex[4])
{
int val = hex2chr(lenbuf_hex);
return (val < 0) ? val : (val << 8) | hex2chr(lenbuf_hex + 2);
}
static char *find_packfile_uri_path(const char *buffer)
{
const char *URI_MARK = "://";
char *path;
int len;
/* First char is sideband mark */
buffer += 1;
len = strspn(buffer, "0123456789abcdefABCDEF");
/* size of SHA1 and SHA256 hash */
if (!(len == 40 || len == 64) || buffer[len] != ' ')
return NULL; /* required "<hash>SP" not seen */
path = strstr(buffer + len + 1, URI_MARK);
if (!path)
return NULL;
path = strchr(path + strlen(URI_MARK), '/');
if (!path || !*(path + 1))
return NULL;
/* position after '/' */
return ++path;
}
enum packet_read_status packet_read_with_status(int fd, char **src_buffer,
size_t *src_len, char *buffer,
unsigned size, int *pktlen,
int options)
{
int len;
char linelen[4];
char *uri_path_start;
if (get_packet_data(fd, src_buffer, src_len, linelen, 4, options) < 0) {
*pktlen = -1;
return PACKET_READ_EOF;
}
len = packet_length(linelen);
if (len < 0) {
if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
return error(_("protocol error: bad line length "
"character: %.4s"), linelen);
die(_("protocol error: bad line length character: %.4s"), linelen);
} else if (!len) {
packet_trace("0000", 4, 0);
*pktlen = 0;
return PACKET_READ_FLUSH;
} else if (len == 1) {
packet_trace("0001", 4, 0);
*pktlen = 0;
return PACKET_READ_DELIM;
} else if (len == 2) {
packet_trace("0002", 4, 0);
*pktlen = 0;
return PACKET_READ_RESPONSE_END;
} else if (len < 4) {
if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
return error(_("protocol error: bad line length %d"),
len);
die(_("protocol error: bad line length %d"), len);
}
len -= 4;
if ((unsigned)len >= size) {
if (options & PACKET_READ_GENTLE_ON_READ_ERROR)
return error(_("protocol error: bad line length %d"),
len);
die(_("protocol error: bad line length %d"), len);
}
if (get_packet_data(fd, src_buffer, src_len, buffer, len, options) < 0) {
*pktlen = -1;
return PACKET_READ_EOF;
}
if ((options & PACKET_READ_CHOMP_NEWLINE) &&
len && buffer[len-1] == '\n')
len--;
buffer[len] = 0;
if (options & PACKET_READ_REDACT_URI_PATH &&
(uri_path_start = find_packfile_uri_path(buffer))) {
const char *redacted = "<redacted>";
struct strbuf tracebuf = STRBUF_INIT;
strbuf_insert(&tracebuf, 0, buffer, len);
strbuf_splice(&tracebuf, uri_path_start - buffer,
strlen(uri_path_start), redacted, strlen(redacted));
packet_trace(tracebuf.buf, tracebuf.len, 0);
strbuf_release(&tracebuf);
} else {
packet_trace(buffer, len, 0);
}
if ((options & PACKET_READ_DIE_ON_ERR_PACKET) &&
starts_with(buffer, "ERR "))
die(_("remote error: %s"), buffer + 4);
*pktlen = len;
return PACKET_READ_NORMAL;
}
int packet_read(int fd, char *buffer, unsigned size, int options)
{
int pktlen = -1;
packet_read_with_status(fd, NULL, NULL, buffer, size, &pktlen,
options);
return pktlen;
}
char *packet_read_line(int fd, int *dst_len)
{
int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
PACKET_READ_CHOMP_NEWLINE);
if (dst_len)
*dst_len = len;
return (len > 0) ? packet_buffer : NULL;
}
int packet_read_line_gently(int fd, int *dst_len, char **dst_line)
{
int len = packet_read(fd, packet_buffer, sizeof(packet_buffer),
PACKET_READ_CHOMP_NEWLINE|PACKET_READ_GENTLE_ON_EOF);
if (dst_len)
*dst_len = len;
if (dst_line)
*dst_line = (len > 0) ? packet_buffer : NULL;
return len;
}
ssize_t read_packetized_to_strbuf(int fd_in, struct strbuf *sb_out, int options)
{
int packet_len;
size_t orig_len = sb_out->len;
size_t orig_alloc = sb_out->alloc;
for (;;) {
strbuf_grow(sb_out, LARGE_PACKET_DATA_MAX);
packet_len = packet_read(fd_in,
/* strbuf_grow() above always allocates one extra byte to
* store a '\0' at the end of the string. packet_read()
* writes a '\0' extra byte at the end, too. Let it know
* that there is already room for the extra byte.
*/
sb_out->buf + sb_out->len, LARGE_PACKET_DATA_MAX+1,
options);
if (packet_len <= 0)
break;
sb_out->len += packet_len;
}
if (packet_len < 0) {
if (orig_alloc == 0)
strbuf_release(sb_out);
else
strbuf_setlen(sb_out, orig_len);
return packet_len;
}
return sb_out->len - orig_len;
}
int recv_sideband(const char *me, int in_stream, int out)
{
char buf[LARGE_PACKET_MAX + 1];
int len;
struct strbuf scratch = STRBUF_INIT;
enum sideband_type sideband_type;
while (1) {
int status = packet_read_with_status(in_stream, NULL, NULL,
buf, LARGE_PACKET_MAX,
&len,
PACKET_READ_GENTLE_ON_EOF);
if (!demultiplex_sideband(me, status, buf, len, 0, &scratch,
&sideband_type))
continue;
switch (sideband_type) {
case SIDEBAND_PRIMARY:
write_or_die(out, buf + 1, len - 1);
break;
default: /* errors: message already written */
if (scratch.len > 0)
BUG("unhandled incomplete sideband: '%s'",
scratch.buf);
return sideband_type;
}
}
}
/* Packet Reader Functions */
void packet_reader_init(struct packet_reader *reader, int fd,
char *src_buffer, size_t src_len,
int options)
{
memset(reader, 0, sizeof(*reader));
reader->fd = fd;
reader->src_buffer = src_buffer;
reader->src_len = src_len;
reader->buffer = packet_buffer;
reader->buffer_size = sizeof(packet_buffer);
reader->options = options;
reader->me = "git";
reader->hash_algo = &hash_algos[GIT_HASH_SHA1];
}
enum packet_read_status packet_reader_read(struct packet_reader *reader)
{
struct strbuf scratch = STRBUF_INIT;
if (reader->line_peeked) {
reader->line_peeked = 0;
return reader->status;
}
/*
* Consume all progress packets until a primary payload packet is
* received
*/
while (1) {
enum sideband_type sideband_type;
reader->status = packet_read_with_status(reader->fd,
&reader->src_buffer,
&reader->src_len,
reader->buffer,
reader->buffer_size,
&reader->pktlen,
reader->options);
if (!reader->use_sideband)
break;
if (demultiplex_sideband(reader->me, reader->status,
reader->buffer, reader->pktlen, 1,
&scratch, &sideband_type))
break;
}
if (reader->status == PACKET_READ_NORMAL)
/* Skip the sideband designator if sideband is used */
reader->line = reader->use_sideband ?
reader->buffer + 1 : reader->buffer;
else
reader->line = NULL;
return reader->status;
}
enum packet_read_status packet_reader_peek(struct packet_reader *reader)
{
/* Only allow peeking a single line */
if (reader->line_peeked)
return reader->status;
/* Peek a line by reading it and setting peeked flag */
packet_reader_read(reader);
reader->line_peeked = 1;
return reader->status;
}
void packet_writer_init(struct packet_writer *writer, int dest_fd)
{
writer->dest_fd = dest_fd;
writer->use_sideband = 0;
}
void packet_writer_write(struct packet_writer *writer, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
packet_write_fmt_1(writer->dest_fd, 0,
writer->use_sideband ? "\001" : "", fmt, args);
va_end(args);
}
void packet_writer_error(struct packet_writer *writer, const char *fmt, ...)
{
va_list args;
va_start(args, fmt);
packet_write_fmt_1(writer->dest_fd, 0,
writer->use_sideband ? "\003" : "ERR ", fmt, args);
va_end(args);
}
void packet_writer_delim(struct packet_writer *writer)
{
packet_delim(writer->dest_fd);
}
void packet_writer_flush(struct packet_writer *writer)
{
packet_flush(writer->dest_fd);
}