diff options
Diffstat (limited to 'src/libgit2/transports/smart_pkt.c')
| -rw-r--r-- | src/libgit2/transports/smart_pkt.c | 637 |
1 files changed, 637 insertions, 0 deletions
diff --git a/src/libgit2/transports/smart_pkt.c b/src/libgit2/transports/smart_pkt.c new file mode 100644 index 000000000..b42edd0d6 --- /dev/null +++ b/src/libgit2/transports/smart_pkt.c @@ -0,0 +1,637 @@ +/* + * Copyright (C) the libgit2 contributors. All rights reserved. + * + * This file is part of libgit2, distributed under the GNU GPL v2 with + * a Linking Exception. For full terms see the included COPYING file. + */ + +#include "common.h" + +#include "smart.h" +#include "util.h" +#include "netops.h" +#include "posix.h" +#include "str.h" + +#include "git2/types.h" +#include "git2/errors.h" +#include "git2/refs.h" +#include "git2/revwalk.h" + +#include <ctype.h> + +#define PKT_LEN_SIZE 4 +static const char pkt_done_str[] = "0009done\n"; +static const char pkt_flush_str[] = "0000"; +static const char pkt_have_prefix[] = "0032have "; +static const char pkt_want_prefix[] = "0032want "; + +static int flush_pkt(git_pkt **out) +{ + git_pkt *pkt; + + pkt = git__malloc(sizeof(git_pkt)); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->type = GIT_PKT_FLUSH; + *out = pkt; + + return 0; +} + +/* the rest of the line will be useful for multi_ack and multi_ack_detailed */ +static int ack_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_ack *pkt; + + pkt = git__calloc(1, sizeof(git_pkt_ack)); + GIT_ERROR_CHECK_ALLOC(pkt); + pkt->type = GIT_PKT_ACK; + + if (git__prefixncmp(line, len, "ACK ")) + goto out_err; + line += 4; + len -= 4; + + if (len < GIT_OID_HEXSZ || git_oid_fromstr(&pkt->oid, line) < 0) + goto out_err; + line += GIT_OID_HEXSZ; + len -= GIT_OID_HEXSZ; + + if (len && line[0] == ' ') { + line++; + len--; + + if (!git__prefixncmp(line, len, "continue")) + pkt->status = GIT_ACK_CONTINUE; + else if (!git__prefixncmp(line, len, "common")) + pkt->status = GIT_ACK_COMMON; + else if (!git__prefixncmp(line, len, "ready")) + pkt->status = GIT_ACK_READY; + else + goto out_err; + } + + *out = (git_pkt *) pkt; + + return 0; + +out_err: + git_error_set(GIT_ERROR_NET, "error parsing ACK pkt-line"); + git__free(pkt); + return -1; +} + +static int nak_pkt(git_pkt **out) +{ + git_pkt *pkt; + + pkt = git__malloc(sizeof(git_pkt)); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->type = GIT_PKT_NAK; + *out = pkt; + + return 0; +} + +static int comment_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_comment *pkt; + size_t alloclen; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_comment), len); + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1); + pkt = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->type = GIT_PKT_COMMENT; + memcpy(pkt->comment, line, len); + pkt->comment[len] = '\0'; + + *out = (git_pkt *) pkt; + + return 0; +} + +static int err_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_err *pkt = NULL; + size_t alloclen; + + /* Remove "ERR " from the line */ + if (git__prefixncmp(line, len, "ERR ")) + goto out_err; + line += 4; + len -= 4; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_progress), len); + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, alloclen, 1); + pkt = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt); + pkt->type = GIT_PKT_ERR; + pkt->len = len; + + memcpy(pkt->error, line, len); + pkt->error[len] = '\0'; + + *out = (git_pkt *) pkt; + + return 0; + +out_err: + git_error_set(GIT_ERROR_NET, "error parsing ERR pkt-line"); + git__free(pkt); + return -1; +} + +static int data_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_data *pkt; + size_t alloclen; + + line++; + len--; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_progress), len); + pkt = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->type = GIT_PKT_DATA; + pkt->len = len; + memcpy(pkt->data, line, len); + + *out = (git_pkt *) pkt; + + return 0; +} + +static int sideband_progress_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_progress *pkt; + size_t alloclen; + + line++; + len--; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, sizeof(git_pkt_progress), len); + pkt = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->type = GIT_PKT_PROGRESS; + pkt->len = len; + memcpy(pkt->data, line, len); + + *out = (git_pkt *) pkt; + + return 0; +} + +static int sideband_error_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_err *pkt; + size_t alloc_len; + + line++; + len--; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, sizeof(git_pkt_err), len); + GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, alloc_len, 1); + pkt = git__malloc(alloc_len); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->type = GIT_PKT_ERR; + pkt->len = (int)len; + memcpy(pkt->error, line, len); + pkt->error[len] = '\0'; + + *out = (git_pkt *)pkt; + + return 0; +} + +/* + * Parse an other-ref line. + */ +static int ref_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_ref *pkt; + size_t alloclen; + + pkt = git__calloc(1, sizeof(git_pkt_ref)); + GIT_ERROR_CHECK_ALLOC(pkt); + pkt->type = GIT_PKT_REF; + + if (len < GIT_OID_HEXSZ || git_oid_fromstr(&pkt->head.oid, line) < 0) + goto out_err; + line += GIT_OID_HEXSZ; + len -= GIT_OID_HEXSZ; + + if (git__prefixncmp(line, len, " ")) + goto out_err; + line++; + len--; + + if (!len) + goto out_err; + + if (line[len - 1] == '\n') + --len; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, len, 1); + pkt->head.name = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt->head.name); + + memcpy(pkt->head.name, line, len); + pkt->head.name[len] = '\0'; + + if (strlen(pkt->head.name) < len) + pkt->capabilities = strchr(pkt->head.name, '\0') + 1; + + *out = (git_pkt *)pkt; + return 0; + +out_err: + git_error_set(GIT_ERROR_NET, "error parsing REF pkt-line"); + if (pkt) + git__free(pkt->head.name); + git__free(pkt); + return -1; +} + +static int ok_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_ok *pkt; + size_t alloc_len; + + pkt = git__malloc(sizeof(*pkt)); + GIT_ERROR_CHECK_ALLOC(pkt); + pkt->type = GIT_PKT_OK; + + if (git__prefixncmp(line, len, "ok ")) + goto out_err; + line += 3; + len -= 3; + + if (len && line[len - 1] == '\n') + --len; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloc_len, len, 1); + pkt->ref = git__malloc(alloc_len); + GIT_ERROR_CHECK_ALLOC(pkt->ref); + + memcpy(pkt->ref, line, len); + pkt->ref[len] = '\0'; + + *out = (git_pkt *)pkt; + return 0; + +out_err: + git_error_set(GIT_ERROR_NET, "error parsing OK pkt-line"); + git__free(pkt); + return -1; +} + +static int ng_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_ng *pkt; + const char *ptr, *eol; + size_t alloclen; + + pkt = git__malloc(sizeof(*pkt)); + GIT_ERROR_CHECK_ALLOC(pkt); + + pkt->ref = NULL; + pkt->type = GIT_PKT_NG; + + eol = line + len; + + if (git__prefixncmp(line, len, "ng ")) + goto out_err; + line += 3; + + if (!(ptr = memchr(line, ' ', eol - line))) + goto out_err; + len = ptr - line; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, len, 1); + pkt->ref = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt->ref); + + memcpy(pkt->ref, line, len); + pkt->ref[len] = '\0'; + + line = ptr + 1; + if (line >= eol) + goto out_err; + + if (!(ptr = memchr(line, '\n', eol - line))) + goto out_err; + len = ptr - line; + + GIT_ERROR_CHECK_ALLOC_ADD(&alloclen, len, 1); + pkt->msg = git__malloc(alloclen); + GIT_ERROR_CHECK_ALLOC(pkt->msg); + + memcpy(pkt->msg, line, len); + pkt->msg[len] = '\0'; + + *out = (git_pkt *)pkt; + return 0; + +out_err: + git_error_set(GIT_ERROR_NET, "invalid packet line"); + git__free(pkt->ref); + git__free(pkt); + return -1; +} + +static int unpack_pkt(git_pkt **out, const char *line, size_t len) +{ + git_pkt_unpack *pkt; + + pkt = git__malloc(sizeof(*pkt)); + GIT_ERROR_CHECK_ALLOC(pkt); + pkt->type = GIT_PKT_UNPACK; + + if (!git__prefixncmp(line, len, "unpack ok")) + pkt->unpack_ok = 1; + else + pkt->unpack_ok = 0; + + *out = (git_pkt *)pkt; + return 0; +} + +static int parse_len(size_t *out, const char *line, size_t linelen) +{ + char num[PKT_LEN_SIZE + 1]; + int i, k, error; + int32_t len; + const char *num_end; + + /* Not even enough for the length */ + if (linelen < PKT_LEN_SIZE) + return GIT_EBUFS; + + memcpy(num, line, PKT_LEN_SIZE); + num[PKT_LEN_SIZE] = '\0'; + + for (i = 0; i < PKT_LEN_SIZE; ++i) { + if (!isxdigit(num[i])) { + /* Make sure there are no special characters before passing to error message */ + for (k = 0; k < PKT_LEN_SIZE; ++k) { + if(!isprint(num[k])) { + num[k] = '.'; + } + } + + git_error_set(GIT_ERROR_NET, "invalid hex digit in length: '%s'", num); + return -1; + } + } + + if ((error = git__strntol32(&len, num, PKT_LEN_SIZE, &num_end, 16)) < 0) + return error; + + if (len < 0) + return -1; + + *out = (size_t) len; + return 0; +} + +/* + * As per the documentation, the syntax is: + * + * pkt-line = data-pkt / flush-pkt + * data-pkt = pkt-len pkt-payload + * pkt-len = 4*(HEXDIG) + * pkt-payload = (pkt-len -4)*(OCTET) + * flush-pkt = "0000" + * + * Which means that the first four bytes are the length of the line, + * in ASCII hexadecimal (including itself) + */ + +int git_pkt_parse_line( + git_pkt **pkt, const char **endptr, const char *line, size_t linelen) +{ + int error; + size_t len; + + if ((error = parse_len(&len, line, linelen)) < 0) { + /* + * If we fail to parse the length, it might be + * because the server is trying to send us the + * packfile already or because we do not yet have + * enough data. + */ + if (error == GIT_EBUFS) + ; + else if (!git__prefixncmp(line, linelen, "PACK")) + git_error_set(GIT_ERROR_NET, "unexpected pack file"); + else + git_error_set(GIT_ERROR_NET, "bad packet length"); + return error; + } + + /* + * Make sure there is enough in the buffer to satisfy + * this line. + */ + if (linelen < len) + return GIT_EBUFS; + + /* + * The length has to be exactly 0 in case of a flush + * packet or greater than PKT_LEN_SIZE, as the decoded + * length includes its own encoded length of four bytes. + */ + if (len != 0 && len < PKT_LEN_SIZE) + return GIT_ERROR; + + line += PKT_LEN_SIZE; + /* + * The Git protocol does not specify empty lines as part + * of the protocol. Not knowing what to do with an empty + * line, we should return an error upon hitting one. + */ + if (len == PKT_LEN_SIZE) { + git_error_set_str(GIT_ERROR_NET, "Invalid empty packet"); + return GIT_ERROR; + } + + if (len == 0) { /* Flush pkt */ + *endptr = line; + return flush_pkt(pkt); + } + + len -= PKT_LEN_SIZE; /* the encoded length includes its own size */ + + if (*line == GIT_SIDE_BAND_DATA) + error = data_pkt(pkt, line, len); + else if (*line == GIT_SIDE_BAND_PROGRESS) + error = sideband_progress_pkt(pkt, line, len); + else if (*line == GIT_SIDE_BAND_ERROR) + error = sideband_error_pkt(pkt, line, len); + else if (!git__prefixncmp(line, len, "ACK")) + error = ack_pkt(pkt, line, len); + else if (!git__prefixncmp(line, len, "NAK")) + error = nak_pkt(pkt); + else if (!git__prefixncmp(line, len, "ERR")) + error = err_pkt(pkt, line, len); + else if (*line == '#') + error = comment_pkt(pkt, line, len); + else if (!git__prefixncmp(line, len, "ok")) + error = ok_pkt(pkt, line, len); + else if (!git__prefixncmp(line, len, "ng")) + error = ng_pkt(pkt, line, len); + else if (!git__prefixncmp(line, len, "unpack")) + error = unpack_pkt(pkt, line, len); + else + error = ref_pkt(pkt, line, len); + + *endptr = line + len; + + return error; +} + +void git_pkt_free(git_pkt *pkt) +{ + if (pkt == NULL) { + return; + } + if (pkt->type == GIT_PKT_REF) { + git_pkt_ref *p = (git_pkt_ref *) pkt; + git__free(p->head.name); + git__free(p->head.symref_target); + } + + if (pkt->type == GIT_PKT_OK) { + git_pkt_ok *p = (git_pkt_ok *) pkt; + git__free(p->ref); + } + + if (pkt->type == GIT_PKT_NG) { + git_pkt_ng *p = (git_pkt_ng *) pkt; + git__free(p->ref); + git__free(p->msg); + } + + git__free(pkt); +} + +int git_pkt_buffer_flush(git_str *buf) +{ + return git_str_put(buf, pkt_flush_str, strlen(pkt_flush_str)); +} + +static int buffer_want_with_caps(const git_remote_head *head, transport_smart_caps *caps, git_str *buf) +{ + git_str str = GIT_STR_INIT; + char oid[GIT_OID_HEXSZ +1] = {0}; + size_t len; + + /* Prefer multi_ack_detailed */ + if (caps->multi_ack_detailed) + git_str_puts(&str, GIT_CAP_MULTI_ACK_DETAILED " "); + else if (caps->multi_ack) + git_str_puts(&str, GIT_CAP_MULTI_ACK " "); + + /* Prefer side-band-64k if the server supports both */ + if (caps->side_band_64k) + git_str_printf(&str, "%s ", GIT_CAP_SIDE_BAND_64K); + else if (caps->side_band) + git_str_printf(&str, "%s ", GIT_CAP_SIDE_BAND); + + if (caps->include_tag) + git_str_puts(&str, GIT_CAP_INCLUDE_TAG " "); + + if (caps->thin_pack) + git_str_puts(&str, GIT_CAP_THIN_PACK " "); + + if (caps->ofs_delta) + git_str_puts(&str, GIT_CAP_OFS_DELTA " "); + + if (git_str_oom(&str)) + return -1; + + len = strlen("XXXXwant ") + GIT_OID_HEXSZ + 1 /* NUL */ + + git_str_len(&str) + 1 /* LF */; + + if (len > 0xffff) { + git_error_set(GIT_ERROR_NET, + "tried to produce packet with invalid length %" PRIuZ, len); + return -1; + } + + git_str_grow_by(buf, len); + git_oid_fmt(oid, &head->oid); + git_str_printf(buf, + "%04xwant %s %s\n", (unsigned int)len, oid, git_str_cstr(&str)); + git_str_dispose(&str); + + GIT_ERROR_CHECK_ALLOC_STR(buf); + + return 0; +} + +/* + * All "want" packets have the same length and format, so what we do + * is overwrite the OID each time. + */ + +int git_pkt_buffer_wants( + const git_remote_head * const *refs, + size_t count, + transport_smart_caps *caps, + git_str *buf) +{ + size_t i = 0; + const git_remote_head *head; + + if (caps->common) { + for (; i < count; ++i) { + head = refs[i]; + if (!head->local) + break; + } + + if (buffer_want_with_caps(refs[i], caps, buf) < 0) + return -1; + + i++; + } + + for (; i < count; ++i) { + char oid[GIT_OID_HEXSZ]; + + head = refs[i]; + if (head->local) + continue; + + git_oid_fmt(oid, &head->oid); + git_str_put(buf, pkt_want_prefix, strlen(pkt_want_prefix)); + git_str_put(buf, oid, GIT_OID_HEXSZ); + git_str_putc(buf, '\n'); + if (git_str_oom(buf)) + return -1; + } + + return git_pkt_buffer_flush(buf); +} + +int git_pkt_buffer_have(git_oid *oid, git_str *buf) +{ + char oidhex[GIT_OID_HEXSZ + 1]; + + memset(oidhex, 0x0, sizeof(oidhex)); + git_oid_fmt(oidhex, oid); + return git_str_printf(buf, "%s%s\n", pkt_have_prefix, oidhex); +} + +int git_pkt_buffer_done(git_str *buf) +{ + return git_str_puts(buf, pkt_done_str); +} |