diff options
Diffstat (limited to 'connect.c')
| -rw-r--r-- | connect.c | 805 |
1 files changed, 805 insertions, 0 deletions
diff --git a/connect.c b/connect.c new file mode 100644 index 0000000000..78448889da --- /dev/null +++ b/connect.c @@ -0,0 +1,805 @@ +#include "git-compat-util.h" +#include "cache.h" +#include "pkt-line.h" +#include "quote.h" +#include "refs.h" + +static char *server_capabilities; + +static int check_ref(const char *name, int len, unsigned int flags) +{ + if (!flags) + return 1; + + if (len < 5 || memcmp(name, "refs/", 5)) + return 0; + + /* Skip the "refs/" part */ + name += 5; + len -= 5; + + /* REF_NORMAL means that we don't want the magic fake tag refs */ + if ((flags & REF_NORMAL) && check_ref_format(name) < 0) + return 0; + + /* REF_HEADS means that we want regular branch heads */ + if ((flags & REF_HEADS) && !memcmp(name, "heads/", 6)) + return 1; + + /* REF_TAGS means that we want tags */ + if ((flags & REF_TAGS) && !memcmp(name, "tags/", 5)) + return 1; + + /* All type bits clear means that we are ok with anything */ + return !(flags & ~REF_NORMAL); +} + +/* + * Read all the refs from the other end + */ +struct ref **get_remote_heads(int in, struct ref **list, + int nr_match, char **match, + unsigned int flags) +{ + *list = NULL; + for (;;) { + struct ref *ref; + unsigned char old_sha1[20]; + static char buffer[1000]; + char *name; + int len, name_len; + + len = packet_read_line(in, buffer, sizeof(buffer)); + if (!len) + break; + if (buffer[len-1] == '\n') + buffer[--len] = 0; + + if (len < 42 || get_sha1_hex(buffer, old_sha1) || buffer[40] != ' ') + die("protocol error: expected sha/ref, got '%s'", buffer); + name = buffer + 41; + + name_len = strlen(name); + if (len != name_len + 41) { + if (server_capabilities) + free(server_capabilities); + server_capabilities = xstrdup(name + name_len + 1); + } + + if (!check_ref(name, name_len, flags)) + continue; + if (nr_match && !path_match(name, nr_match, match)) + continue; + ref = xcalloc(1, sizeof(*ref) + len - 40); + hashcpy(ref->old_sha1, old_sha1); + memcpy(ref->name, buffer + 41, len - 40); + *list = ref; + list = &ref->next; + } + return list; +} + +int server_supports(const char *feature) +{ + return server_capabilities && + strstr(server_capabilities, feature) != NULL; +} + +int get_ack(int fd, unsigned char *result_sha1) +{ + static char line[1000]; + int len = packet_read_line(fd, line, sizeof(line)); + + if (!len) + die("git-fetch-pack: expected ACK/NAK, got EOF"); + if (line[len-1] == '\n') + line[--len] = 0; + if (!strcmp(line, "NAK")) + return 0; + if (!strncmp(line, "ACK ", 4)) { + if (!get_sha1_hex(line+4, result_sha1)) { + if (strstr(line+45, "continue")) + return 2; + return 1; + } + } + die("git-fetch_pack: expected ACK/NAK, got '%s'", line); +} + +int path_match(const char *path, int nr, char **match) +{ + int i; + int pathlen = strlen(path); + + for (i = 0; i < nr; i++) { + char *s = match[i]; + int len = strlen(s); + + if (!len || len > pathlen) + continue; + if (memcmp(path + pathlen - len, s, len)) + continue; + if (pathlen > len && path[pathlen - len - 1] != '/') + continue; + *s = 0; + return (i + 1); + } + return 0; +} + +struct refspec { + char *src; + char *dst; + char force; +}; + +/* + * A:B means fast forward remote B with local A. + * +A:B means overwrite remote B with local A. + * +A is a shorthand for +A:A. + * A is a shorthand for A:A. + * :B means delete remote B. + */ +static struct refspec *parse_ref_spec(int nr_refspec, char **refspec) +{ + int i; + struct refspec *rs = xcalloc(sizeof(*rs), (nr_refspec + 1)); + for (i = 0; i < nr_refspec; i++) { + char *sp, *dp, *ep; + sp = refspec[i]; + if (*sp == '+') { + rs[i].force = 1; + sp++; + } + ep = strchr(sp, ':'); + if (ep) { + dp = ep + 1; + *ep = 0; + } + else + dp = sp; + rs[i].src = sp; + rs[i].dst = dp; + } + rs[nr_refspec].src = rs[nr_refspec].dst = NULL; + return rs; +} + +static int count_refspec_match(const char *pattern, + struct ref *refs, + struct ref **matched_ref) +{ + int patlen = strlen(pattern); + struct ref *matched_weak = NULL; + struct ref *matched = NULL; + int weak_match = 0; + int match = 0; + + for (weak_match = match = 0; refs; refs = refs->next) { + char *name = refs->name; + int namelen = strlen(name); + int weak_match; + + if (namelen < patlen || + memcmp(name + namelen - patlen, pattern, patlen)) + continue; + if (namelen != patlen && name[namelen - patlen - 1] != '/') + continue; + + /* A match is "weak" if it is with refs outside + * heads or tags, and did not specify the pattern + * in full (e.g. "refs/remotes/origin/master") or at + * least from the toplevel (e.g. "remotes/origin/master"); + * otherwise "git push $URL master" would result in + * ambiguity between remotes/origin/master and heads/master + * at the remote site. + */ + if (namelen != patlen && + patlen != namelen - 5 && + strncmp(name, "refs/heads/", 11) && + strncmp(name, "refs/tags/", 10)) { + /* We want to catch the case where only weak + * matches are found and there are multiple + * matches, and where more than one strong + * matches are found, as ambiguous. One + * strong match with zero or more weak matches + * are acceptable as a unique match. + */ + matched_weak = refs; + weak_match++; + } + else { + matched = refs; + match++; + } + } + if (!matched) { + *matched_ref = matched_weak; + return weak_match; + } + else { + *matched_ref = matched; + return match; + } +} + +static void link_dst_tail(struct ref *ref, struct ref ***tail) +{ + **tail = ref; + *tail = &ref->next; + **tail = NULL; +} + +static struct ref *try_explicit_object_name(const char *name) +{ + unsigned char sha1[20]; + struct ref *ref; + int len; + + if (!*name) { + ref = xcalloc(1, sizeof(*ref) + 20); + strcpy(ref->name, "(delete)"); + hashclr(ref->new_sha1); + return ref; + } + if (get_sha1(name, sha1)) + return NULL; + len = strlen(name) + 1; + ref = xcalloc(1, sizeof(*ref) + len); + memcpy(ref->name, name, len); + hashcpy(ref->new_sha1, sha1); + return ref; +} + +static int match_explicit_refs(struct ref *src, struct ref *dst, + struct ref ***dst_tail, struct refspec *rs) +{ + int i, errs; + for (i = errs = 0; rs[i].src; i++) { + struct ref *matched_src, *matched_dst; + + matched_src = matched_dst = NULL; + switch (count_refspec_match(rs[i].src, src, &matched_src)) { + case 1: + break; + case 0: + /* The source could be in the get_sha1() format + * not a reference name. :refs/other is a + * way to delete 'other' ref at the remote end. + */ + matched_src = try_explicit_object_name(rs[i].src); + if (matched_src) + break; + errs = 1; + error("src refspec %s does not match any.", + rs[i].src); + break; + default: + errs = 1; + error("src refspec %s matches more than one.", + rs[i].src); + break; + } + switch (count_refspec_match(rs[i].dst, dst, &matched_dst)) { + case 1: + break; + case 0: + if (!memcmp(rs[i].dst, "refs/", 5)) { + int len = strlen(rs[i].dst) + 1; + matched_dst = xcalloc(1, sizeof(*dst) + len); + memcpy(matched_dst->name, rs[i].dst, len); + link_dst_tail(matched_dst, dst_tail); + } + else if (!strcmp(rs[i].src, rs[i].dst) && + matched_src) { + /* pushing "master:master" when + * remote does not have master yet. + */ + int len = strlen(matched_src->name) + 1; + matched_dst = xcalloc(1, sizeof(*dst) + len); + memcpy(matched_dst->name, matched_src->name, + len); + link_dst_tail(matched_dst, dst_tail); + } + else { + errs = 1; + error("dst refspec %s does not match any " + "existing ref on the remote and does " + "not start with refs/.", rs[i].dst); + } + break; + default: + errs = 1; + error("dst refspec %s matches more than one.", + rs[i].dst); + break; + } + if (errs) + continue; + if (matched_dst->peer_ref) { + errs = 1; + error("dst ref %s receives from more than one src.", + matched_dst->name); + } + else { + matched_dst->peer_ref = matched_src; + matched_dst->force = rs[i].force; + } + } + return -errs; +} + +static struct ref *find_ref_by_name(struct ref *list, const char *name) +{ + for ( ; list; list = list->next) + if (!strcmp(list->name, name)) + return list; + return NULL; +} + +int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail, + int nr_refspec, char **refspec, int all) +{ + struct refspec *rs = parse_ref_spec(nr_refspec, refspec); + + if (nr_refspec) + return match_explicit_refs(src, dst, dst_tail, rs); + + /* pick the remainder */ + for ( ; src; src = src->next) { + struct ref *dst_peer; + if (src->peer_ref) + continue; + dst_peer = find_ref_by_name(dst, src->name); + if ((dst_peer && dst_peer->peer_ref) || (!dst_peer && !all)) + continue; + if (!dst_peer) { + /* Create a new one and link it */ + int len = strlen(src->name) + 1; + dst_peer = xcalloc(1, sizeof(*dst_peer) + len); + memcpy(dst_peer->name, src->name, len); + hashcpy(dst_peer->new_sha1, src->new_sha1); + link_dst_tail(dst_peer, dst_tail); + } + dst_peer->peer_ref = src; + } + return 0; +} + +enum protocol { + PROTO_LOCAL = 1, + PROTO_SSH, + PROTO_GIT, +}; + +static enum protocol get_protocol(const char *name) +{ + if (!strcmp(name, "ssh")) + return PROTO_SSH; + if (!strcmp(name, "git")) + return PROTO_GIT; + if (!strcmp(name, "git+ssh")) + return PROTO_SSH; + if (!strcmp(name, "ssh+git")) + return PROTO_SSH; + die("I don't handle protocol '%s'", name); +} + +#define STR_(s) # s +#define STR(s) STR_(s) + +#ifndef NO_IPV6 + +/* + * Returns a connected socket() fd, or else die()s. + */ +static int git_tcp_connect_sock(char *host) +{ + int sockfd = -1, saved_errno = 0; + char *colon, *end; + const char *port = STR(DEFAULT_GIT_PORT); + struct addrinfo hints, *ai0, *ai; + int gai; + + if (host[0] == '[') { + end = strchr(host + 1, ']'); + if (end) { + *end = 0; + end++; + host++; + } else + end = host; + } else + end = host; + colon = strchr(end, ':'); + + if (colon) { + *colon = 0; + port = colon + 1; + } + + memset(&hints, 0, sizeof(hints)); + hints.ai_socktype = SOCK_STREAM; + hints.ai_protocol = IPPROTO_TCP; + + gai = getaddrinfo(host, port, &hints, &ai); + if (gai) + die("Unable to look up %s (%s)", host, gai_strerror(gai)); + + for (ai0 = ai; ai; ai = ai->ai_next) { + sockfd = socket(ai->ai_family, + ai->ai_socktype, ai->ai_protocol); + if (sockfd < 0) { + saved_errno = errno; + continue; + } + if (connect(sockfd, ai->ai_addr, ai->ai_addrlen) < 0) { + saved_errno = errno; + close(sockfd); + sockfd = -1; + continue; + } + break; + } + + freeaddrinfo(ai0); + + if (sockfd < 0) + die("unable to connect a socket (%s)", strerror(saved_errno)); + + return sockfd; +} + +#else /* NO_IPV6 */ + +/* + * Returns a connected socket() fd, or else die()s. + */ +static int git_tcp_connect_sock(char *host) +{ + int sockfd = -1, saved_errno = 0; + char *colon, *end; + char *port = STR(DEFAULT_GIT_PORT), *ep; + struct hostent *he; + struct sockaddr_in sa; + char **ap; + unsigned int nport; + + if (host[0] == '[') { + end = strchr(host + 1, ']'); + if (end) { + *end = 0; + end++; + host++; + } else + end = host; + } else + end = host; + colon = strchr(end, ':'); + + if (colon) { + *colon = 0; + port = colon + 1; + } + + he = gethostbyname(host); + if (!he) + die("Unable to look up %s (%s)", host, hstrerror(h_errno)); + nport = strtoul(port, &ep, 10); + if ( ep == port || *ep ) { + /* Not numeric */ + struct servent *se = getservbyname(port,"tcp"); + if ( !se ) + die("Unknown port %s\n", port); + nport = se->s_port; + } + + for (ap = he->h_addr_list; *ap; ap++) { + sockfd = socket(he->h_addrtype, SOCK_STREAM, 0); + if (sockfd < 0) { + saved_errno = errno; + continue; + } + + memset(&sa, 0, sizeof sa); + sa.sin_family = he->h_addrtype; + sa.sin_port = htons(nport); + memcpy(&sa.sin_addr, *ap, he->h_length); + + if (connect(sockfd, (struct sockaddr *)&sa, sizeof sa) < 0) { + saved_errno = errno; + close(sockfd); + sockfd = -1; + continue; + } + break; + } + + if (sockfd < 0) + die("unable to connect a socket (%s)", strerror(saved_errno)); + + return sockfd; +} + +#endif /* NO_IPV6 */ + + +static void git_tcp_connect(int fd[2], char *host) +{ + int sockfd = git_tcp_connect_sock(host); + + fd[0] = sockfd; + fd[1] = dup(sockfd); +} + + +static char *git_proxy_command; +static const char *rhost_name; +static int rhost_len; + +static int git_proxy_command_options(const char *var, const char *value) +{ + if (!strcmp(var, "core.gitproxy")) { + const char *for_pos; + int matchlen = -1; + int hostlen; + + if (git_proxy_command) + return 0; + /* [core] + * ;# matches www.kernel.org as well + * gitproxy = netcatter-1 for kernel.org + * gitproxy = netcatter-2 for sample.xz + * gitproxy = netcatter-default + */ + for_pos = strstr(value, " for "); + if (!for_pos) + /* matches everybody */ + matchlen = strlen(value); + else { + hostlen = strlen(for_pos + 5); + if (rhost_len < hostlen) + matchlen = -1; + else if (!strncmp(for_pos + 5, + rhost_name + rhost_len - hostlen, + hostlen) && + ((rhost_len == hostlen) || + rhost_name[rhost_len - hostlen -1] == '.')) + matchlen = for_pos - value; + else + matchlen = -1; + } + if (0 <= matchlen) { + /* core.gitproxy = none for kernel.org */ + if (matchlen == 4 && + !memcmp(value, "none", 4)) + matchlen = 0; + git_proxy_command = xmalloc(matchlen + 1); + memcpy(git_proxy_command, value, matchlen); + git_proxy_command[matchlen] = 0; + } + return 0; + } + + return git_default_config(var, value); +} + +static int git_use_proxy(const char *host) +{ + rhost_name = host; + rhost_len = strlen(host); + git_proxy_command = getenv("GIT_PROXY_COMMAND"); + git_config(git_proxy_command_options); + rhost_name = NULL; + return (git_proxy_command && *git_proxy_command); +} + +static void git_proxy_connect(int fd[2], char *host) +{ + const char *port = STR(DEFAULT_GIT_PORT); + char *colon, *end; + int pipefd[2][2]; + pid_t pid; + + if (host[0] == '[') { + end = strchr(host + 1, ']'); + if (end) { + *end = 0; + end++; + host++; + } else + end = host; + } else + end = host; + colon = strchr(end, ':'); + + if (colon) { + *colon = 0; + port = colon + 1; + } + + if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0) + die("unable to create pipe pair for communication"); + pid = fork(); + if (!pid) { + dup2(pipefd[1][0], 0); + dup2(pipefd[0][1], 1); + close(pipefd[0][0]); + close(pipefd[0][1]); + close(pipefd[1][0]); + close(pipefd[1][1]); + execlp(git_proxy_command, git_proxy_command, host, port, NULL); + die("exec failed"); + } + if (pid < 0) + die("fork failed"); + fd[0] = pipefd[0][0]; + fd[1] = pipefd[1][1]; + close(pipefd[0][1]); + close(pipefd[1][0]); +} + +#define MAX_CMD_LEN 1024 + +/* + * This returns 0 if the transport protocol does not need fork(2), + * or a process id if it does. Once done, finish the connection + * with finish_connect() with the value returned from this function + * (it is safe to call finish_connect() with 0 to support the former + * case). + * + * Does not return a negative value on error; it just dies. + */ +pid_t git_connect(int fd[2], char *url, const char *prog) +{ + char *host, *path = url; + char *end; + int c; + int pipefd[2][2]; + pid_t pid; + enum protocol protocol = PROTO_LOCAL; + int free_path = 0; + + /* Without this we cannot rely on waitpid() to tell + * what happened to our children. + */ + signal(SIGCHLD, SIG_DFL); + + host = strstr(url, "://"); + if(host) { + *host = '\0'; + protocol = get_protocol(url); + host += 3; + c = '/'; + } else { + host = url; + c = ':'; + } + + if (host[0] == '[') { + end = strchr(host + 1, ']'); + if (end) { + *end = 0; + end++; + host++; + } else + end = host; + } else + end = host; + + path = strchr(end, c); + if (c == ':') { + if (path) { + protocol = PROTO_SSH; + *path++ = '\0'; + } else + path = host; + } + + if (!path || !*path) + die("No path specified. See 'man git-pull' for valid url syntax"); + + /* + * null-terminate hostname and point path to ~ for URL's like this: + * ssh://host.xz/~user/repo + */ + if (protocol != PROTO_LOCAL && host != url) { + char *ptr = path; + if (path[1] == '~') + path++; + else { + path = xstrdup(ptr); + free_path = 1; + } + + *ptr = '\0'; + } + + if (protocol == PROTO_GIT) { + /* These underlying connection commands die() if they + * cannot connect. + */ + char *target_host = xstrdup(host); + if (git_use_proxy(host)) + git_proxy_connect(fd, host); + else + git_tcp_connect(fd, host); + /* + * Separate original protocol components prog and path + * from extended components with a NUL byte. + */ + packet_write(fd[1], + "%s %s%chost=%s%c", + prog, path, 0, + target_host, 0); + free(target_host); + if (free_path) + free(path); + return 0; + } + + if (pipe(pipefd[0]) < 0 || pipe(pipefd[1]) < 0) + die("unable to create pipe pair for communication"); + pid = fork(); + if (pid < 0) + die("unable to fork"); + if (!pid) { + char command[MAX_CMD_LEN]; + char *posn = command; + int size = MAX_CMD_LEN; + int of = 0; + + of |= add_to_string(&posn, &size, prog, 0); + of |= add_to_string(&posn, &size, " ", 0); + of |= add_to_string(&posn, &size, path, 1); + + if (of) + die("command line too long"); + + dup2(pipefd[1][0], 0); + dup2(pipefd[0][1], 1); + close(pipefd[0][0]); + close(pipefd[0][1]); + close(pipefd[1][0]); + close(pipefd[1][1]); + if (protocol == PROTO_SSH) { + const char *ssh, *ssh_basename; + ssh = getenv("GIT_SSH"); + if (!ssh) ssh = "ssh"; + ssh_basename = strrchr(ssh, '/'); + if (!ssh_basename) + ssh_basename = ssh; + else + ssh_basename++; + execlp(ssh, ssh_basename, host, command, NULL); + } + else { + unsetenv(ALTERNATE_DB_ENVIRONMENT); + unsetenv(DB_ENVIRONMENT); + unsetenv(GIT_DIR_ENVIRONMENT); + unsetenv(GRAFT_ENVIRONMENT); + unsetenv(INDEX_ENVIRONMENT); + execlp("sh", "sh", "-c", command, NULL); + } + die("exec failed"); + } + fd[0] = pipefd[0][0]; + fd[1] = pipefd[1][1]; + close(pipefd[0][1]); + close(pipefd[1][0]); + if (free_path) + free(path); + return pid; +} + +int finish_connect(pid_t pid) +{ + if (pid == 0) + return 0; + + while (waitpid(pid, NULL, 0) < 0) { + if (errno != EINTR) + return -1; + } + return 0; +} |