kmx git

/*
 * Copyright (c) 2019 Ori Bernstein <ori@openbsd.org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <sys/types.h>
#include <sys/queue.h>
#include <sys/uio.h>
#include <sys/time.h>
#include <sys/stat.h>

#include <stdint.h>
#include <errno.h>
#include <imsg.h>
#include <limits.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sha1.h>
#include <fcntl.h>
#include <unistd.h>
#include <zlib.h>
#include <err.h>

#include "got_error.h"
#include "got_object.h"
#include "got_path.h"
#include "got_version.h"
#include "got_fetch.h"
#include "got_reference.h"

#include "got_lib_sha1.h"
#include "got_lib_delta.h"
#include "got_lib_object.h"
#include "got_lib_object_parse.h"
#include "got_lib_privsep.h"
#include "got_lib_pack.h"

#ifndef nitems
#define nitems(_a)	(sizeof((_a)) / sizeof((_a)[0]))
#endif

struct got_object *indexed;
static int chattygot;
static struct got_object_id zhash = {.sha1={0}};

static const struct got_error *
readn(ssize_t *off, int fd, void *buf, size_t n)
{
	ssize_t r;

	*off = 0;
	while (*off != n) {
		r = read(fd, buf + *off, n - *off);
		if (r == -1)
			return got_error_from_errno("read");
		if (r == 0)
			return NULL;
		*off += r;
	}
	return NULL;
}

static const struct got_error *
flushpkt(int fd)
{
	ssize_t w;

	if (chattygot > 1)
		fprintf(stderr, "%s: writepkt: 0000\n", getprogname());

	w = write(fd, "0000", 4);
	if (w == -1)
		return got_error_from_errno("write");
	if (w != 4)
		return got_error(GOT_ERR_IO);
	return NULL;
}

/*
 * Packet header contains a 4-byte hexstring which specifies the length
 * of data which follows.
 */
static const struct got_error *
read_pkthdr(int *datalen, int fd)
{
	static const struct got_error *err = NULL;
	char lenstr[5];
	long len;
	char *e;
	int n, i;
	ssize_t r;

	*datalen = 0;

	err = readn(&r, fd, lenstr, 4);
	if (err)
		return err;
	if (r == 0) {
		/* implicit "0000" */
		if (chattygot > 1)
			fprintf(stderr, "%s: readpkt: 0000\n", getprogname());
		return NULL;
	}
	if (r != 4)
		return got_error_msg(GOT_ERR_BAD_PACKET,
		    "wrong packet header length");

	lenstr[4] = '\0';
	for (i = 0; i < 4; i++) {
		if (!isprint((unsigned char)lenstr[i]))
			return got_error_msg(GOT_ERR_BAD_PACKET,
			    "unprintable character in packet length field");
	}
	for (i = 0; i < 4; i++) {
		if (!isxdigit((unsigned char)lenstr[i])) {
			if (chattygot)
				fprintf(stderr, "%s: bad length: '%s'\n",
				    getprogname(), lenstr);
			return got_error_msg(GOT_ERR_BAD_PACKET,
			    "packet length not specified in hex");
		}
	}
	errno = 0;
	len = strtol(lenstr, &e, 16);
	if (lenstr[0] == '\0' || *e != '\0')
		return got_error(GOT_ERR_BAD_PACKET);
	if (errno == ERANGE && (len == LONG_MAX || len == LONG_MIN))
		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
	if (len > INT_MAX || len < INT_MIN)
		return got_error_msg(GOT_ERR_BAD_PACKET, "bad packet length");
	n = len;
	if (n == 0)
		return NULL;
	if (n <= 4)
		return got_error_msg(GOT_ERR_BAD_PACKET, "packet too short");
	n  -= 4;

	*datalen = n;
	return NULL;
}

static const struct got_error *
readpkt(int *outlen, int fd, char *buf, int buflen)
{
	const struct got_error *err = NULL;
	int datalen, i;
	ssize_t n;

	err = read_pkthdr(&datalen, fd);
	if (err)
		return err;

	if (datalen > buflen)
		return got_error(GOT_ERR_NO_SPACE);

	err = readn(&n, fd, buf, datalen);
	if (err)
		return err;
	if (n != datalen)
		return got_error_msg(GOT_ERR_BAD_PACKET, "short packet");

	if (chattygot > 1) {
		fprintf(stderr, "%s: readpkt: %zd:\t", getprogname(), n);
		for (i = 0; i < n; i++) {
			if (isprint(buf[i]))
				fputc(buf[i], stderr);
			else
				fprintf(stderr, "[0x%.2x]", buf[i]);
		}
		fputc('\n', stderr);
	}

	*outlen = n;
	return NULL;
}

static const struct got_error *
writepkt(int fd, char *buf, int nbuf)
{
	char len[5];
	int i;
	ssize_t w;

	if (snprintf(len, sizeof(len), "%04x", nbuf + 4) >= sizeof(len))
		return got_error(GOT_ERR_NO_SPACE);
	w = write(fd, len, 4);
	if (w == -1)
		return got_error_from_errno("write");
	if (w != 4)
		return got_error(GOT_ERR_IO);
	w = write(fd, buf, nbuf);
	if (w == -1)
		return got_error_from_errno("write");
	if (w != nbuf)
		return got_error(GOT_ERR_IO);
	if (chattygot > 1) {
		fprintf(stderr, "%s: writepkt: %s:\t", getprogname(), len);
		for (i = 0; i < nbuf; i++) {
			if (isprint(buf[i]))
				fputc(buf[i], stderr);
			else
				fprintf(stderr, "[0x%.2x]", buf[i]);
		}
		fputc('\n', stderr);
	}
	return NULL;
}

static void
match_remote_ref(struct got_pathlist_head *have_refs,
    struct got_object_id *my_id, char *refname)
{
	struct got_pathlist_entry *pe;

	/* XXX zero-hash signifies we don't have this ref;
	 * we should use a flag instead */
	memset(my_id, 0, sizeof(*my_id));

	TAILQ_FOREACH(pe, have_refs, entry) {
		struct got_object_id *id = pe->data;
		if (strcmp(pe->path, refname) == 0) { 
			memcpy(my_id, id, sizeof(*my_id));
			break;
		}
	}
}

static int
match_branch(const char *branch, const char *wanted_branch)
{
	if (strncmp(branch, "refs/heads/", 11) != 0)
		return 0;

	if (strncmp(wanted_branch, "refs/heads/", 11) == 0)
		wanted_branch += 11;

	return (strcmp(branch + 11, wanted_branch) == 0);
}

static int
match_wanted_ref(const char *refname, const char *wanted_ref)
{
	if (strncmp(refname, "refs/", 5) != 0)
		return 0;
	refname += 5;

	/*
	 * Prevent fetching of references that won't make any
	 * sense outside of the remote repository's context.
	 */
	if (strncmp(refname, "got/", 4) == 0)
		return 0;
	if (strncmp(refname, "remotes/", 8) == 0)
		return 0;

	if (strncmp(wanted_ref, "refs/", 5) == 0)
		wanted_ref += 5;

	/* Allow prefix match. */
	if (got_path_is_child(refname, wanted_ref, strlen(wanted_ref)))
		return 1;

	/* Allow exact match. */
	return (strcmp(refname, wanted_ref) == 0);
}

static const struct got_error *
tokenize_refline(char **tokens, char *line, int len, int maxtokens)
{
	const struct got_error *err = NULL;
	char *p;
	size_t i, n = 0;

	for (i = 0; i < maxtokens; i++)
		tokens[i] = NULL;

	for (i = 0; n < len && i < maxtokens; i++) {
		while (isspace(*line)) {
			line++;
			n++;
		}
		p = line;
		while (*line != '\0' &&
		    (!isspace(*line) || i == maxtokens - 1)) {
			line++;
			n++;
		}
		tokens[i] = strndup(p, line - p);
		if (tokens[i] == NULL) {
			err = got_error_from_errno("strndup");
			goto done;
		}
		/* Skip \0 field-delimiter at end of token. */
		while (line[0] == '\0' && n < len) {
			line++;
			n++;
		}
	}
	if (i <= 2)
		err = got_error(GOT_ERR_NOT_REF);
done:
	if (err) {
		int j;
		for (j = 0; j < i; j++) {
			free(tokens[j]);
			tokens[j] = NULL;
		}
	}
	return err;
}

static const struct got_error *
parse_refline(char **id_str, char **refname, char **server_capabilities,
    char *line, int len)
{
	const struct got_error *err = NULL;
	char *tokens[3];

	err = tokenize_refline(tokens, line, len, nitems(tokens));
	if (err)
		return err;

	if (tokens[0])
		*id_str = tokens[0];
	if (tokens[1])
		*refname = tokens[1];
	if (tokens[2]) {
		char *p;
		*server_capabilities = tokens[2];
		p = strrchr(*server_capabilities, '\n');
		if (p)
			*p = '\0';
	}

	return NULL;
}

#define GOT_CAPA_AGENT			"agent"
#define GOT_CAPA_OFS_DELTA		"ofs-delta"
#define GOT_CAPA_SIDE_BAND_64K		"side-band-64k"

#define GOT_SIDEBAND_PACKFILE_DATA	1
#define GOT_SIDEBAND_PROGRESS_INFO	2
#define GOT_SIDEBAND_ERROR_INFO		3


struct got_capability {
	const char *key;
	const char *value;
};
static const struct got_capability got_capabilities[] = {
	{ GOT_CAPA_AGENT, "got/" GOT_VERSION_STR },
	{ GOT_CAPA_OFS_DELTA, NULL },
	{ GOT_CAPA_SIDE_BAND_64K, NULL },
};

static const struct got_error *
match_capability(char **my_capabilities, const char *capa,
    const struct got_capability *mycapa)
{
	char *equalsign;
	char *s;

	equalsign = strchr(capa, '=');
	if (equalsign) {
		if (strncmp(capa, mycapa->key, equalsign - capa) != 0)
			return NULL;
	} else {
		if (strcmp(capa, mycapa->key) != 0)
			return NULL;
	}

	if (asprintf(&s, "%s %s%s%s",
	    *my_capabilities != NULL ? *my_capabilities : "",
	    mycapa->key,
	    mycapa->value != NULL ? "=" : "",
	    mycapa->value != NULL? mycapa->value : "") == -1)
		return got_error_from_errno("asprintf");

	free(*my_capabilities);
	*my_capabilities = s;
	return NULL;
}

static const struct got_error *
add_symref(struct got_pathlist_head *symrefs, char *capa)
{
	const struct got_error *err = NULL;
	char *colon, *name = NULL, *target = NULL;

	/* Need at least "A:B" */
	if (strlen(capa) < 3)
		return NULL;

	colon = strchr(capa, ':');
	if (colon == NULL)
		return NULL;

	*colon = '\0';
	name = strdup(capa);
	if (name == NULL)
		return got_error_from_errno("strdup");

	target = strdup(colon + 1);
	if (target == NULL) {
		err = got_error_from_errno("strdup");
		goto done;
	}

	/* We can't validate the ref itself here. The main process will. */
	err = got_pathlist_append(symrefs, name, target);
done:
	if (err) {
		free(name);
		free(target);
	}
	return err;
}

static const struct got_error *
match_capabilities(char **my_capabilities, struct got_pathlist_head *symrefs,
    char *server_capabilities)
{
	const struct got_error *err = NULL;
	char *capa, *equalsign;
	size_t i;

	*my_capabilities = NULL;
	do {
		capa = strsep(&server_capabilities, " ");
		if (capa == NULL)
			return NULL;

		equalsign = strchr(capa, '=');
		if (equalsign != NULL &&
		    strncmp(capa, "symref", equalsign - capa) == 0) {
			err = add_symref(symrefs, equalsign + 1);
			if (err)
				break;
			continue;
		}

		for (i = 0; i < nitems(got_capabilities); i++) {
			err = match_capability(my_capabilities,
			    capa, &got_capabilities[i]);
			if (err)
				break;
		}
	} while (capa);

	if (*my_capabilities == NULL) {
		*my_capabilities = strdup("");
		if (*my_capabilities == NULL)
			err = got_error_from_errno("strdup");
	}
	return err;
}

static const struct got_error *
send_fetch_server_progress(struct imsgbuf *ibuf, const char *msg, size_t msglen)
{
	if (msglen > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
		return got_error(GOT_ERR_NO_SPACE);

	if (msglen == 0)
		return NULL;

	if (imsg_compose(ibuf, GOT_IMSG_FETCH_SERVER_PROGRESS, 0, 0, -1,
	    msg, msglen) == -1)
		return got_error_from_errno(
		    "imsg_compose FETCH_SERVER_PROGRESS");

	return got_privsep_flush_imsg(ibuf);
}

static const struct got_error *
send_fetch_download_progress(struct imsgbuf *ibuf, off_t bytes)
{
	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DOWNLOAD_PROGRESS, 0, 0, -1,
	    &bytes, sizeof(bytes)) == -1)
		return got_error_from_errno(
		    "imsg_compose FETCH_DOWNLOAD_PROGRESS");

	return got_privsep_flush_imsg(ibuf);
}

static const struct got_error *
send_fetch_done(struct imsgbuf *ibuf, uint8_t *pack_sha1)
{
	if (imsg_compose(ibuf, GOT_IMSG_FETCH_DONE, 0, 0, -1,
	    pack_sha1, SHA1_DIGEST_LENGTH) == -1)
		return got_error_from_errno("imsg_compose FETCH");
	return got_privsep_flush_imsg(ibuf);
}



static const struct got_error *
fetch_progress(struct imsgbuf *ibuf, const char *buf, size_t len)
{
	size_t i;

	if (len == 0)
		return NULL;

	/*
	 * Truncate messages which exceed the maximum imsg payload size.
	 * Server may send up to 64k.
	 */
	if (len > MAX_IMSGSIZE - IMSG_HEADER_SIZE)
		len = MAX_IMSGSIZE - IMSG_HEADER_SIZE;

	/* Only allow printable ASCII. */
	for (i = 0; i < len; i++) {
		if (isprint((unsigned char)buf[i]) ||
		    isspace((unsigned char)buf[i]))
			continue;
		return got_error_msg(GOT_ERR_BAD_PACKET,
		    "non-printable progress message received from server");
	}

	return send_fetch_server_progress(ibuf, buf, len);
}

static const struct got_error *
fetch_error(const char *buf, size_t len)
{
	static char msg[1024];
	size_t i;

	for (i = 0; i < len && i < sizeof(msg) - 1; i++) {
		if (!isprint(buf[i]))
			return got_error_msg(GOT_ERR_BAD_PACKET,
			    "non-printable error message received from server");
		msg[i] = buf[i];
	}
	msg[i] = '\0';
	return got_error_msg(GOT_ERR_FETCH_FAILED, msg);
}

static const struct got_error *
send_fetch_symrefs(struct imsgbuf *ibuf, struct got_pathlist_head *symrefs)
{
	const struct got_error *err = NULL;
	struct ibuf *wbuf;
	size_t len, nsymrefs = 0;
	struct got_pathlist_entry *pe;

	len = sizeof(struct got_imsg_fetch_symrefs);
	TAILQ_FOREACH(pe, symrefs, entry) {
		const char *target = pe->data;
		len += sizeof(struct got_imsg_fetch_symref) +
		    pe->path_len + strlen(target);
		nsymrefs++;
	}

	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
		return got_error(GOT_ERR_NO_SPACE);

	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_SYMREFS, 0, 0, len);
	if (wbuf == NULL)
		return got_error_from_errno("imsg_create FETCH_SYMREFS");

	/* Keep in sync with struct got_imsg_fetch_symrefs definition! */
	if (imsg_add(wbuf, &nsymrefs, sizeof(nsymrefs)) == -1) {
		err = got_error_from_errno("imsg_add FETCH_SYMREFS");
		ibuf_free(wbuf);
		return err;
	}

	TAILQ_FOREACH(pe, symrefs, entry) {
		const char *name = pe->path;
		size_t name_len = pe->path_len;
		const char *target = pe->data;
		size_t target_len = strlen(target);

		/* Keep in sync with struct got_imsg_fetch_symref definition! */
		if (imsg_add(wbuf, &name_len, sizeof(name_len)) == -1) {
			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
			ibuf_free(wbuf);
			return err;
		}
		if (imsg_add(wbuf, &target_len, sizeof(target_len)) == -1) {
			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
			ibuf_free(wbuf);
			return err;
		}
		if (imsg_add(wbuf, name, name_len) == -1) {
			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
			ibuf_free(wbuf);
			return err;
		}
		if (imsg_add(wbuf, target, target_len) == -1) {
			err = got_error_from_errno("imsg_add FETCH_SYMREFS");
			ibuf_free(wbuf);
			return err;
		}
	}

	wbuf->fd = -1;
	imsg_close(ibuf, wbuf);
	return got_privsep_flush_imsg(ibuf);
}

static const struct got_error *
send_fetch_ref(struct imsgbuf *ibuf, struct got_object_id *refid,
    const char *refname)
{
	const struct got_error *err = NULL;
	struct ibuf *wbuf;
	size_t len, reflen = strlen(refname);

	len = sizeof(struct got_imsg_fetch_ref) + reflen;
	if (len >= MAX_IMSGSIZE - IMSG_HEADER_SIZE)
		return got_error(GOT_ERR_NO_SPACE);

	wbuf = imsg_create(ibuf, GOT_IMSG_FETCH_REF, 0, 0, len);
	if (wbuf == NULL)
		return got_error_from_errno("imsg_create FETCH_REF");

	/* Keep in sync with struct got_imsg_fetch_ref definition! */
	if (imsg_add(wbuf, refid->sha1, SHA1_DIGEST_LENGTH) == -1) {
		err = got_error_from_errno("imsg_add FETCH_REF");
		ibuf_free(wbuf);
		return err;
	}
	if (imsg_add(wbuf, refname, reflen) == -1) {
		err = got_error_from_errno("imsg_add FETCH_REF");
		ibuf_free(wbuf);
		return err;
	}

	wbuf->fd = -1;
	imsg_close(ibuf, wbuf);
	return got_privsep_flush_imsg(ibuf);
}

static const struct got_error *
fetch_pack(int fd, int packfd, uint8_t *pack_sha1,
    struct got_pathlist_head *have_refs, int fetch_all_branches,
    struct got_pathlist_head *wanted_branches,
    struct got_pathlist_head *wanted_refs, int list_refs_only,
    struct imsgbuf *ibuf)
{
	const struct got_error *err = NULL;
	char buf[GOT_FETCH_PKTMAX];
	char hashstr[SHA1_DIGEST_STRING_LENGTH];
	struct got_object_id *have, *want;
	int is_firstpkt = 1, nref = 0, refsz = 16;
	int i, n, nwant = 0, nhave = 0, acked = 0;
	off_t packsz = 0, last_reported_packsz = 0;
	char *id_str = NULL, *refname = NULL;
	char *server_capabilities = NULL, *my_capabilities = NULL;
	const char *default_branch = NULL;
	struct got_pathlist_head symrefs;
	struct got_pathlist_entry *pe;
	int sent_my_capabilites = 0, have_sidebands = 0;
	int found_branch = 0;
	SHA1_CTX sha1_ctx;
	uint8_t sha1_buf[SHA1_DIGEST_LENGTH];
	size_t sha1_buf_len = 0;
	ssize_t w;

	TAILQ_INIT(&symrefs);
	SHA1Init(&sha1_ctx);

	have = malloc(refsz * sizeof(have[0]));
	if (have == NULL)
		return got_error_from_errno("malloc");
	want = malloc(refsz * sizeof(want[0]));
	if (want == NULL) {
		err = got_error_from_errno("malloc");
		goto done;
	}
	while (1) {
		err = readpkt(&n, fd, buf, sizeof(buf));
		if (err)
			goto done;
		if (n == 0)
			break;
		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
			err = fetch_error(&buf[4], n - 4);
			goto done;
		}
		err = parse_refline(&id_str, &refname, &server_capabilities,
		    buf, n);
		if (err)
			goto done;
		if (is_firstpkt) {
			if (chattygot && server_capabilities[0] != '\0')
				fprintf(stderr, "%s: server capabilities: %s\n",
				    getprogname(), server_capabilities);
			err = match_capabilities(&my_capabilities, &symrefs,
			    server_capabilities);
			if (err)
				goto done;
			if (chattygot)
				fprintf(stderr, "%s: my capabilities:%s\n",
				    getprogname(), my_capabilities);
			err = send_fetch_symrefs(ibuf, &symrefs);
			if (err)
				goto done;
			is_firstpkt = 0;
			if (!fetch_all_branches) {
				TAILQ_FOREACH(pe, &symrefs, entry) {
					const char *name = pe->path;
					const char *symref_target = pe->data;
					if (strcmp(name, GOT_REF_HEAD) != 0)
						continue;
					default_branch = symref_target;
					break;
				}
			}
			continue;
		}
		if (strstr(refname, "^{}")) {
			if (chattygot) {
				fprintf(stderr, "%s: ignoring %s\n",
				    getprogname(), refname);
			}
			continue;
		}

		if (strncmp(refname, "refs/heads/", 11) == 0) {
			if (fetch_all_branches || list_refs_only) {
				found_branch = 1;
			} else if (!TAILQ_EMPTY(wanted_branches)) {
				TAILQ_FOREACH(pe, wanted_branches, entry) {
					if (match_branch(refname, pe->path))
						break;
				}
				if (pe == NULL) {
					if (chattygot) {
						fprintf(stderr,
						    "%s: ignoring %s\n",
						    getprogname(), refname);
					}
					continue;
				}
				found_branch = 1;
			} else if (default_branch != NULL) {
				if (!match_branch(refname, default_branch)) {
					if (chattygot) {
						fprintf(stderr,
						    "%s: ignoring %s\n",
						    getprogname(), refname);
					}
					continue;
				}
				found_branch = 1;
			}
		} else if (strncmp(refname, "refs/tags/", 10) != 0) {
			if (!TAILQ_EMPTY(wanted_refs)) {
				TAILQ_FOREACH(pe, wanted_refs, entry) {
					if (match_wanted_ref(refname, pe->path))
						break;
				}
				if (pe == NULL) {
					if (chattygot) {
						fprintf(stderr,
						    "%s: ignoring %s\n",
						    getprogname(), refname);
					}
					continue;
				}
				found_branch = 1;
			} else if (!list_refs_only) {
				if (chattygot) {
					fprintf(stderr, "%s: ignoring %s\n",
					    getprogname(), refname);
				}
				continue;
			}
		}

		if (refsz == nref + 1) {
			refsz *= 2;
			have = reallocarray(have, refsz, sizeof(have[0]));
			if (have == NULL) {
				err = got_error_from_errno("reallocarray");
				goto done;
			}
			want = reallocarray(want, refsz, sizeof(want[0]));
			if (want == NULL) {
				err = got_error_from_errno("reallocarray");
				goto done;
			}
		}
		if (!got_parse_sha1_digest(want[nref].sha1, id_str)) {
			err = got_error(GOT_ERR_BAD_OBJ_ID_STR);
			goto done;
		}
		match_remote_ref(have_refs, &have[nref], refname);
		err = send_fetch_ref(ibuf, &want[nref], refname);
		if (err)
			goto done;

		if (chattygot)
			fprintf(stderr, "%s: %s will be fetched\n",
			    getprogname(), refname);
		if (chattygot > 1) {
			char *theirs, *mine;
			err = got_object_id_str(&theirs, &want[nref]);
			if (err)
				goto done;
			err = got_object_id_str(&mine, &have[nref]);
			if (err) {
				free(theirs);
				goto done;
			}
			fprintf(stderr, "%s: remote: %s\n%s: local:  %s\n",
			    getprogname(), theirs, getprogname(), mine);
			free(theirs);
			free(mine);
		}
		nref++;
	}

	if (list_refs_only)
		goto done;

	/* Abort if we haven't found any branch to fetch. */
	if (!found_branch) {
		err = got_error(GOT_ERR_FETCH_NO_BRANCH);
		goto done;
	}

	for (i = 0; i < nref; i++) {
		if (got_object_id_cmp(&have[i], &want[i]) == 0)
			continue;
		got_sha1_digest_to_str(want[i].sha1, hashstr, sizeof(hashstr));
		n = snprintf(buf, sizeof(buf), "want %s%s\n", hashstr,
		    sent_my_capabilites ? "" : my_capabilities);
		if (n >= sizeof(buf)) {
			err = got_error(GOT_ERR_NO_SPACE);
			goto done;
		}
		err = writepkt(fd, buf, n);
		if (err)
			goto done;
		sent_my_capabilites = 1;
		nwant++;
	}
	err = flushpkt(fd);
	if (err)
		goto done;

	if (nwant == 0)
		goto done;

	for (i = 0; i < nref; i++) {
		if (got_object_id_cmp(&have[i], &zhash) == 0)
			continue;
		got_sha1_digest_to_str(have[i].sha1, hashstr, sizeof(hashstr));
		n = snprintf(buf, sizeof(buf), "have %s\n", hashstr);
		if (n >= sizeof(buf)) {
			err = got_error(GOT_ERR_NO_SPACE);
			goto done;
		}
		err = writepkt(fd, buf, n);
		if (err)
			goto done;
		nhave++;
	}

	while (nhave > 0 && !acked) {
		struct got_object_id common_id;

		/* The server should ACK the object IDs we need. */
		err = readpkt(&n, fd, buf, sizeof(buf));
		if (err)
			goto done;
		if (n >= 4 && strncmp(buf, "ERR ", 4) == 0) {
			err = fetch_error(&buf[4], n - 4);
			goto done;
		}
		if (n >= 4 && strncmp(buf, "NAK\n", 4) == 0) {
			/* Server has not located our objects yet. */
			continue;
		}
		if (n < 4 + SHA1_DIGEST_STRING_LENGTH ||
		    strncmp(buf, "ACK ", 4) != 0) {
			err = got_error_msg(GOT_ERR_BAD_PACKET,
			    "unexpected message from server");
			goto done;
		}
		if (!got_parse_sha1_digest(common_id.sha1, buf + 4)) {
			err = got_error_msg(GOT_ERR_BAD_PACKET,
			    "bad object ID in ACK packet from server");
			goto done;
		}
		acked++;
	}

	n = snprintf(buf, sizeof(buf), "done\n");
	err = writepkt(fd, buf, n);
	if (err)
		goto done;

	if (nhave == 0) {
		err = readpkt(&n, fd, buf, sizeof(buf));
		if (err)
			goto done;
		if (n != 4 || strncmp(buf, "NAK\n", n) != 0) {
			err = got_error_msg(GOT_ERR_BAD_PACKET,
			    "unexpected message from server");
			goto done;
		}
	}

	if (chattygot)
		fprintf(stderr, "%s: fetching...\n", getprogname());

	if (my_capabilities != NULL &&
	    strstr(my_capabilities, GOT_CAPA_SIDE_BAND_64K) != NULL)
		have_sidebands = 1;

	while (1) {
		ssize_t r = 0;
		int datalen = -1;

		if (have_sidebands) {
			err = read_pkthdr(&datalen, fd);
			if (err)
				goto done;
			if (datalen <= 0)
				break;

			/* Read sideband channel ID (one byte). */
			r = read(fd, buf, 1);
			if (r == -1) {
				err = got_error_from_errno("read");
				goto done;
			}
			if (r != 1) {
				err = got_error_msg(GOT_ERR_BAD_PACKET,
				    "short packet");
				goto done;
			}
			if (datalen > sizeof(buf) - 5) {
				err = got_error_msg(GOT_ERR_BAD_PACKET,
				    "bad packet length");
				goto done;
			}
			datalen--; /* sideband ID has been read */
			if (buf[0] == GOT_SIDEBAND_PACKFILE_DATA) {
				/* Read packfile data. */
				err = readn(&r, fd, buf, datalen);
				if (err)
					goto done;
				if (r != datalen) {
					err = got_error_msg(GOT_ERR_BAD_PACKET,
					    "packet too short");
					goto done;
				}
			} else if (buf[0] == GOT_SIDEBAND_PROGRESS_INFO) {
				err = readn(&r, fd, buf, datalen);
				if (err)
					goto done;
				if (r != datalen) {
					err = got_error_msg(GOT_ERR_BAD_PACKET,
					    "packet too short");
					goto done;
				}
				err = fetch_progress(ibuf, buf, r);
				if (err)
					goto done;
				continue;
			} else if (buf[0] == GOT_SIDEBAND_ERROR_INFO) {
				err = readn(&r, fd, buf, datalen);
				if (err)
					goto done;
				if (r != datalen) {
					err = got_error_msg(GOT_ERR_BAD_PACKET,
					    "packet too short");
					goto done;
				}
				err = fetch_error(buf, r);
				goto done;
			} else if (buf[0] == 'A') {
				err = readn(&r, fd, buf, datalen);
				if (err)
					goto done;
				if (r != datalen) {
					err = got_error_msg(GOT_ERR_BAD_PACKET,
					    "packet too short");
					goto done;
				}
				/*
				 * Git server responds with ACK after 'done'
				 * even though multi_ack is disabled?!?
				 */
				buf[r] = '\0';
				if (strncmp(buf, "CK ", 3) == 0)
					continue; /* ignore */
				err = got_error_msg(GOT_ERR_BAD_PACKET,
				    "unexpected message from server");
				goto done;
			} else {
				err = got_error_msg(GOT_ERR_BAD_PACKET,
				    "unknown side-band received from server");
				goto done;
			}
		} else {
			/* No sideband channel. Every byte is packfile data. */
			err = readn(&r, fd, buf, sizeof buf);
			if (err)
				goto done;
			if (r <= 0)
				break;
		}

		/*
		 * An expected SHA1 checksum sits at the end of the pack file.
		 * Since we don't know the file size ahead of time we have to
		 * keep SHA1_DIGEST_LENGTH bytes buffered and avoid mixing
		 * those bytes into our SHA1 checksum computation until we
		 * know for sure that additional pack file data bytes follow.
		 *
		 * We can assume r > 0 since otherwise the loop would exit.
		 */
		if (r < SHA1_DIGEST_LENGTH) {
			if (sha1_buf_len < SHA1_DIGEST_LENGTH) {
				/*
				 * If there's enough buffered + read data to
				 * fill up the buffer then shift a sufficient
				 * amount of bytes out at the front to make
				 * room, mixing those bytes into the checksum.
				 */
				while (sha1_buf_len > 0 &&
				    sha1_buf_len + r > SHA1_DIGEST_LENGTH) {
					SHA1Update(&sha1_ctx, sha1_buf, 1);
					memmove(sha1_buf, sha1_buf + 1, 1);
					sha1_buf_len--;
				}

				/* Buffer potential checksum bytes. */
				memcpy(sha1_buf + sha1_buf_len, buf, r);
				sha1_buf_len += r;
			} else {
				/*
				 * Mix in previously buffered bytes which
				 * are not part of the checksum after all.
				 */
				SHA1Update(&sha1_ctx, sha1_buf, r);

				/* Update potential checksum buffer. */
				memmove(sha1_buf, sha1_buf + r,
				    sha1_buf_len - r);
				memcpy(sha1_buf + sha1_buf_len - r, buf, r);
			}
		} else {
			/* Mix in any previously buffered bytes. */
			SHA1Update(&sha1_ctx, sha1_buf, sha1_buf_len);

			/* Mix in bytes read minus potential checksum bytes. */
			SHA1Update(&sha1_ctx, buf, r - SHA1_DIGEST_LENGTH);

			/* Buffer potential checksum bytes. */
			memcpy(sha1_buf, buf + r - SHA1_DIGEST_LENGTH,
			    SHA1_DIGEST_LENGTH);
			sha1_buf_len = SHA1_DIGEST_LENGTH;
		}

		/* Write packfile data to temporary pack file. */
		w = write(packfd, buf, r);
		if (w == -1) {
			err = got_error_from_errno("write");
			goto done;
		}
		if (w != r) {
			err = got_error(GOT_ERR_IO);
			goto done;
		}
		packsz += w;

		/* Don't send too many progress privsep messages. */
		if (packsz > last_reported_packsz + 1024) {
			err = send_fetch_download_progress(ibuf, packsz);
			if (err)
				goto done;
			last_reported_packsz = packsz;
		}
	}
	err = send_fetch_download_progress(ibuf, packsz);
	if (err)
		goto done;

	SHA1Final(pack_sha1, &sha1_ctx);
	if (sha1_buf_len != SHA1_DIGEST_LENGTH ||
	    memcmp(pack_sha1, sha1_buf, sha1_buf_len) != 0) {
		err = got_error_msg(GOT_ERR_BAD_PACKFILE,
		    "pack file checksum mismatch");
	}
done:
	TAILQ_FOREACH(pe, &symrefs, entry) {
		free((void *)pe->path);
		free(pe->data);
	}
	got_pathlist_free(&symrefs);
	free(have);
	free(want);
	free(id_str);
	free(refname);
	free(server_capabilities);
	return err;
}


int
main(int argc, char **argv)
{
	const struct got_error *err = NULL;
	int fetchfd, packfd = -1, i;
	uint8_t pack_sha1[SHA1_DIGEST_LENGTH];
	struct imsgbuf ibuf;
	struct imsg imsg;
	struct got_pathlist_head have_refs;
	struct got_pathlist_head wanted_branches;
	struct got_pathlist_head wanted_refs;
	struct got_pathlist_entry *pe;
	struct got_imsg_fetch_request fetch_req;
	struct got_imsg_fetch_have_ref href;
	struct got_imsg_fetch_wanted_branch wbranch;
	struct got_imsg_fetch_wanted_ref wref;
	size_t datalen;
#if 0
	static int attached;
	while (!attached)
		sleep (1);
#endif

	TAILQ_INIT(&have_refs);
	TAILQ_INIT(&wanted_branches);
	TAILQ_INIT(&wanted_refs);

	imsg_init(&ibuf, GOT_IMSG_FD_CHILD);
#ifndef PROFILE
	/* revoke access to most system calls */
	if (pledge("stdio recvfd", NULL) == -1) {
		err = got_error_from_errno("pledge");
		got_privsep_send_error(&ibuf, err);
		return 1;
	}
#endif
	if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
		if (err->code == GOT_ERR_PRIVSEP_PIPE)
			err = NULL;
		goto done;
	}
	if (imsg.hdr.type == GOT_IMSG_STOP)
		goto done;
	if (imsg.hdr.type != GOT_IMSG_FETCH_REQUEST) {
		err = got_error(GOT_ERR_PRIVSEP_MSG);
		goto done;
	}
	datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
	if (datalen < sizeof(fetch_req)) {
		err = got_error(GOT_ERR_PRIVSEP_LEN);
		goto done;
	}
	memcpy(&fetch_req, imsg.data, sizeof(fetch_req));
	fetchfd = imsg.fd;
	imsg_free(&imsg);

	if (fetch_req.verbosity > 0)
		chattygot += fetch_req.verbosity;

	for (i = 0; i < fetch_req.n_have_refs; i++) {
		struct got_object_id *id;
		char *refname;

		if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
			if (err->code == GOT_ERR_PRIVSEP_PIPE)
				err = NULL;
			goto done;
		}
		if (imsg.hdr.type == GOT_IMSG_STOP)
			goto done;
		if (imsg.hdr.type != GOT_IMSG_FETCH_HAVE_REF) {
			err = got_error(GOT_ERR_PRIVSEP_MSG);
			goto done;
		}
		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
		if (datalen < sizeof(href)) {
			err = got_error(GOT_ERR_PRIVSEP_LEN);
			goto done;
		}
		memcpy(&href, imsg.data, sizeof(href));
		if (datalen - sizeof(href) < href.name_len) {
			err = got_error(GOT_ERR_PRIVSEP_LEN);
			goto done;
		}
		refname = malloc(href.name_len + 1);
		if (refname == NULL) {
			err = got_error_from_errno("malloc");
			goto done;
		}
		memcpy(refname, imsg.data + sizeof(href), href.name_len);
		refname[href.name_len] = '\0';

		id = malloc(sizeof(*id));
		if (id == NULL) {
			free(refname);
			err = got_error_from_errno("malloc");
			goto done;
		}
		memcpy(id->sha1, href.id, SHA1_DIGEST_LENGTH);
		err = got_pathlist_append(&have_refs, refname, id);
		if (err) {
			free(refname);
			free(id);
			goto done;
		}

		imsg_free(&imsg);
	}

	for (i = 0; i < fetch_req.n_wanted_branches; i++) {
		char *refname;

		if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
			if (err->code == GOT_ERR_PRIVSEP_PIPE)
				err = NULL;
			goto done;
		}
		if (imsg.hdr.type == GOT_IMSG_STOP)
			goto done;
		if (imsg.hdr.type != GOT_IMSG_FETCH_WANTED_BRANCH) {
			err = got_error(GOT_ERR_PRIVSEP_MSG);
			goto done;
		}
		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
		if (datalen < sizeof(wbranch)) {
			err = got_error(GOT_ERR_PRIVSEP_LEN);
			goto done;
		}
		memcpy(&wbranch, imsg.data, sizeof(wbranch));
		if (datalen - sizeof(wbranch) < wbranch.name_len) {
			err = got_error(GOT_ERR_PRIVSEP_LEN);
			goto done;
		}
		refname = malloc(wbranch.name_len + 1);
		if (refname == NULL) {
			err = got_error_from_errno("malloc");
			goto done;
		}
		memcpy(refname, imsg.data + sizeof(wbranch), wbranch.name_len);
		refname[wbranch.name_len] = '\0';

		err = got_pathlist_append(&wanted_branches, refname, NULL);
		if (err) {
			free(refname);
			goto done;
		}

		imsg_free(&imsg);
	}

	for (i = 0; i < fetch_req.n_wanted_refs; i++) {
		char *refname;

		if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
			if (err->code == GOT_ERR_PRIVSEP_PIPE)
				err = NULL;
			goto done;
		}
		if (imsg.hdr.type == GOT_IMSG_STOP)
			goto done;
		if (imsg.hdr.type != GOT_IMSG_FETCH_WANTED_REF) {
			err = got_error(GOT_ERR_PRIVSEP_MSG);
			goto done;
		}
		datalen = imsg.hdr.len - IMSG_HEADER_SIZE;
		if (datalen < sizeof(wref)) {
			err = got_error(GOT_ERR_PRIVSEP_LEN);
			goto done;
		}
		memcpy(&wref, imsg.data, sizeof(wref));
		if (datalen - sizeof(wref) < wref.name_len) {
			err = got_error(GOT_ERR_PRIVSEP_LEN);
			goto done;
		}
		refname = malloc(wref.name_len + 1);
		if (refname == NULL) {
			err = got_error_from_errno("malloc");
			goto done;
		}
		memcpy(refname, imsg.data + sizeof(wref), wref.name_len);
		refname[wref.name_len] = '\0';

		err = got_pathlist_append(&wanted_refs, refname, NULL);
		if (err) {
			free(refname);
			goto done;
		}

		imsg_free(&imsg);
	}

	if ((err = got_privsep_recv_imsg(&imsg, &ibuf, 0)) != 0) {
		if (err->code == GOT_ERR_PRIVSEP_PIPE)
			err = NULL;
		goto done;
	}
	if (imsg.hdr.type == GOT_IMSG_STOP)
		goto done;
	if (imsg.hdr.type != GOT_IMSG_FETCH_OUTFD) {
		err = got_error(GOT_ERR_PRIVSEP_MSG);
		goto done;
	}
	if (imsg.hdr.len - IMSG_HEADER_SIZE != 0) {
		err = got_error(GOT_ERR_PRIVSEP_LEN);
		goto done;
	}
	packfd = imsg.fd;

	err = fetch_pack(fetchfd, packfd, pack_sha1, &have_refs,
	    fetch_req.fetch_all_branches, &wanted_branches,
	    &wanted_refs, fetch_req.list_refs_only, &ibuf);
done:
	TAILQ_FOREACH(pe, &have_refs, entry) {
		free((char *)pe->path);
		free(pe->data);
	}
	got_pathlist_free(&have_refs);
	TAILQ_FOREACH(pe, &wanted_branches, entry)
		free((char *)pe->path);
	got_pathlist_free(&wanted_branches);
	if (fetchfd != -1 && close(fetchfd) == -1 && err == NULL)
		err = got_error_from_errno("close");
	if (packfd != -1 && close(packfd) == -1 && err == NULL)
		err = got_error_from_errno("close");
	if (err != NULL)
		got_privsep_send_error(&ibuf, err);
	else
		err = send_fetch_done(&ibuf, pack_sha1);
	if (err != NULL) {
		fprintf(stderr, "%s: %s\n", getprogname(), err->msg);
		got_privsep_send_error(&ibuf, err);
	}

	exit(0);
}
thodg/got/libexec/got-fetch-pack/got-fetch-pack.c

Commit

libexec/got-fetch-pack/got-fetch-pack.c
