#include #include #include #include #include #include #include #include #include #include #include #include "dive.h" #include "membuffer.h" #include "strndup.h" #include "qthelperfromc.h" #include "git-access.h" #include "gettext.h" /* * The libgit2 people are incompetent at making libraries. They randomly change * the interfaces, often just renaming things without any sane way to know which * version you should check for etc etc. It's a disgrace. */ #if !LIBGIT2_VER_MAJOR && LIBGIT2_VER_MINOR < 22 #define git_remote_lookup(res, repo, name) git_remote_load(res, repo, name) #if LIBGIT2_VER_MINOR <= 20 #define git_remote_fetch(remote, refspecs, signature, reflog) git_remote_fetch(remote) #else #define git_remote_fetch(remote, refspecs, signature, reflog) git_remote_fetch(remote, signature, reflog) #endif #endif #if !USE_LIBGIT23_API && !LIBGIT2_VER_MAJOR && LIBGIT2_VER_MINOR == 22 #define git_remote_push(remote,refspecs,opts) git_remote_push(remote,refspecs,opts,NULL,NULL) #define git_reference_set_target(out,ref,id,log_message) git_reference_set_target(out,ref,id,NULL,log_message) #define git_reset(repo,target,reset_type,checkout_opts) git_reset(repo,target,reset_type,checkout_opts,NULL,NULL) #endif /* * api break introduced in libgit2 master after 0.22 - let's guess this is the v0.23 API */ #if USE_LIBGIT23_API #define git_branch_create(out, repo, branch_name, target, force, signature, log_message) \ git_branch_create(out, repo, branch_name, target, force) #endif static char *get_local_dir(const char *remote, const char *branch) { SHA_CTX ctx; unsigned char hash[20]; // That zero-byte update is so that we don't get hash // collisions for "repo1 branch" vs "repo 1branch". SHA1_Init(&ctx); SHA1_Update(&ctx, remote, strlen(remote)); SHA1_Update(&ctx, "", 1); SHA1_Update(&ctx, branch, strlen(branch)); SHA1_Final(hash, &ctx); return format_string("%s/%02x%02x%02x%02x%02x%02x%02x%02x", system_default_directory(), hash[0], hash[1], hash[2], hash[3], hash[4], hash[5], hash[6], hash[7]); } static int check_clean(const char *path, unsigned int status, void *payload) { status &= ~GIT_STATUS_CURRENT | GIT_STATUS_IGNORED; if (!status) return 0; report_error("WARNING: Git cache directory modified (path %s)", path); return 1; } /* * The remote is strictly newer than the local branch. */ static int reset_to_remote(git_repository *repo, git_reference *local, const git_oid *new_id) { git_checkout_options opts = GIT_CHECKOUT_OPTIONS_INIT; git_object *target; // If it's not checked out (bare or not HEAD), just update the reference */ if (git_repository_is_bare(repo) || git_branch_is_head(local) != 1) { git_reference *out; if (git_reference_set_target(&out, local, new_id, "Update to remote")) return report_error("Could not update local ref to newer remote ref"); git_reference_free(out); // Not really an error, just informational report_error("Updated local branch from remote"); return 0; } if (git_object_lookup(&target, repo, new_id, GIT_OBJ_COMMIT)) return report_error("Could not look up remote commit"); opts.checkout_strategy = GIT_CHECKOUT_SAFE; if (git_reset(repo, target, GIT_RESET_HARD, &opts)) return report_error("Local head checkout failed after update"); // Not really an error, just informational report_error("Updated local information from remote"); return 0; } #if USE_LIBGIT23_API int credential_ssh_cb(git_cred **out, const char *url, const char *username_from_url, unsigned int allowed_types, void *payload) { const char *priv_key = format_string("%s/%s", system_default_directory(), "ssrf_remote.key"); const char *passphrase = prefs.cloud_storage_password ? strdup(prefs.cloud_storage_password) : strdup(""); return git_cred_ssh_key_new(out, username_from_url, NULL, priv_key, passphrase); } int credential_https_cb(git_cred **out, const char *url, const char *username_from_url, unsigned int allowed_types, void *payload) { const char *username = prefs.cloud_storage_email_encoded; const char *password = prefs.cloud_storage_password ? strdup(prefs.cloud_storage_password) : strdup(""); return git_cred_userpass_plaintext_new(out, username, password); } #endif static int update_remote(git_repository *repo, git_remote *origin, git_reference *local, git_reference *remote, enum remote_transport rt) { git_push_options opts = GIT_PUSH_OPTIONS_INIT; git_strarray refspec; const char *name = git_reference_name(local); refspec.count = 1; refspec.strings = (char **)&name; #if USE_LIBGIT23_API if (rt == RT_SSH) opts.callbacks.credentials = credential_ssh_cb; else if (rt == RT_HTTPS) opts.callbacks.credentials = credential_https_cb; #endif if (git_remote_push(origin, &refspec, &opts)) return report_error("Unable to update remote with current local cache state (%s)", giterr_last()->message); return 0; } static int try_to_update(git_repository *repo, git_remote *origin, git_reference *local, git_reference *remote, enum remote_transport rt) { git_oid base; const git_oid *local_id, *remote_id; if (!git_reference_cmp(local, remote)) return 0; // Dirty modified state in the working tree? We're not going // to update either way if (git_status_foreach(repo, check_clean, NULL)) return report_error("local cached copy is dirty, skipping update"); local_id = git_reference_target(local); remote_id = git_reference_target(remote); if (!local_id || !remote_id) return report_error("Unable to get local or remote SHA1"); if (git_merge_base(&base, repo, local_id, remote_id)) return report_error("Unable to find common commit of local and remote branches"); /* Is the remote strictly newer? Use it */ if (git_oid_equal(&base, local_id)) return reset_to_remote(repo, local, remote_id); /* Is the local repo the more recent one? See if we can update upstream */ if (git_oid_equal(&base, remote_id)) return update_remote(repo, origin, local, remote, rt); /* Merging a bare repository always needs user action */ if (git_repository_is_bare(repo)) return report_error("Local and remote have diverged, merge of bare branch needed"); /* Merging will definitely need the head branch too */ if (git_branch_is_head(local) != 1) return report_error("Local and remote do not match, local branch not HEAD - cannot update"); /* * Some day we migth try a clean merge here. * * But I couldn't find any good examples of this, so for now * you'd need to merge divergent histories manually. But we've * at least verified above that we have a working tree and the * current branch is checked out and clean, so we *could* try * to merge. */ return report_error("Local and remote have diverged, need to merge"); } static int check_remote_status(git_repository *repo, git_remote *origin, const char *branch, enum remote_transport rt) { int error = 0; git_reference *local_ref, *remote_ref; if (git_branch_lookup(&local_ref, repo, branch, GIT_BRANCH_LOCAL)) return report_error("Git cache branch %s no longer exists", branch); if (git_branch_upstream(&remote_ref, local_ref)) { /* so there is no upstream branch for our branch; that's a problem. /* let's push our branch */ git_strarray refspec; git_reference_list(&refspec, repo); #if USE_LIBGIT23_API git_push_options opts = GIT_PUSH_OPTIONS_INIT; if (rt == RT_SSH) opts.callbacks.credentials = credential_ssh_cb; else if (rt == RT_HTTPS) opts.callbacks.credentials = credential_https_cb; error = git_remote_push(origin, &refspec, &opts); #else error = git_remote_push(origin, &refspec, NULL); #endif } else { error = try_to_update(repo, origin, local_ref, remote_ref, rt); git_reference_free(remote_ref); } git_reference_free(local_ref); return error; } int sync_with_remote(git_repository *repo, const char *remote, const char *branch, enum remote_transport rt) { int error; git_remote *origin; char *proxy_string; git_config *conf; git_repository_config(&conf, repo); if (rt == RT_HTTPS && getProxyString(&proxy_string)) { git_config_set_string(conf, "http.proxy", proxy_string); free(proxy_string); } else { git_config_set_string(conf, "http.proxy", ""); } /* * NOTE! Remote errors are reported, but are nonfatal: * we still successfully return the local repository. */ error = git_remote_lookup(&origin, repo, "origin"); if (error) { report_error("Repository '%s' origin lookup failed (%s)", remote, giterr_last()->message); return 0; } if (rt == RT_HTTPS && !canReachCloudServer()) { // this is not an error, just a warning message, so return 0 report_error("Cannot connect to cloud server, working with local copy"); return 0; } #if USE_LIBGIT23_API git_fetch_options opts = GIT_FETCH_OPTIONS_INIT; if (rt == RT_SSH) opts.callbacks.credentials = credential_ssh_cb; else if (rt == RT_HTTPS) opts.callbacks.credentials = credential_https_cb; error = git_remote_fetch(origin, NULL, &opts, NULL); #else error = git_remote_fetch(origin, NULL, NULL, NULL); #endif // NOTE! A fetch error is not fatal, we just report it if (error) { report_error("Unable to fetch remote '%s'", remote); error = 0; } else { error = check_remote_status(repo, origin, branch, rt); } git_remote_free(origin); return error; } static git_repository *update_local_repo(const char *localdir, const char *remote, const char *branch, enum remote_transport rt) { int error; git_repository *repo = NULL; error = git_repository_open(&repo, localdir); if (error) { report_error("Unable to open git cache repository at %s: %s", localdir, giterr_last()->message); return NULL; } sync_with_remote(repo, remote, branch, rt); return repo; } static int repository_create_cb(git_repository **out, const char *path, int bare, void *payload) { char *proxy_string; git_config *conf; int ret = git_repository_init(out, path, bare); if (getProxyString(&proxy_string)) { git_repository_config(&conf, *out); git_config_set_string(conf, "http.proxy", proxy_string); free(proxy_string); } return ret; } /* this should correctly initialize both the local and remote * repository for the Subsurface cloud storage */ static git_repository *create_and_push_remote(const char *localdir, const char *remote, const char *branch) { git_repository *repo; git_config *conf; int len; char *variable_name, *merge_head; /* first make sure the directory for the local cache exists */ subsurface_mkdir(localdir); /* set up the origin to point to our remote */ git_repository_init_options init_opts = GIT_REPOSITORY_INIT_OPTIONS_INIT; init_opts.origin_url = remote; /* now initialize the repository with */ git_repository_init_ext(&repo, localdir, &init_opts); /* create a config so we can set the remote tracking branch */ git_repository_config(&conf, repo); len = sizeof("branch..remote") + strlen(branch); variable_name = malloc(len); snprintf(variable_name, len, "branch.%s.remote", branch); git_config_set_string(conf, variable_name, "origin"); /* we know this is shorter than the previous one, so we reuse the variable*/ snprintf(variable_name, len, "branch.%s.merge", branch); len = sizeof("refs/heads/") + strlen(branch); merge_head = malloc(len); snprintf(merge_head, len, "refs/heads/%s", branch); git_config_set_string(conf, variable_name, merge_head); /* finally create an empty commit and push it to the remote */ if (do_git_save(repo, branch, remote, false, true)) return NULL; return(repo); } static git_repository *create_local_repo(const char *localdir, const char *remote, const char *branch, enum remote_transport rt) { int error; git_repository *cloned_repo = NULL; git_clone_options opts = GIT_CLONE_OPTIONS_INIT; #if USE_LIBGIT23_API if (rt == RT_SSH) opts.fetch_opts.callbacks.credentials = credential_ssh_cb; else if (rt == RT_HTTPS) opts.fetch_opts.callbacks.credentials = credential_https_cb; opts.repository_cb = repository_create_cb; #endif opts.checkout_branch = branch; if (rt == RT_HTTPS && !canReachCloudServer()) return 0; error = git_clone(&cloned_repo, remote, localdir, &opts); if (error) { char *msg = giterr_last()->message; int len = sizeof("Reference 'refs/remotes/origin/' not found" + strlen(branch)); char *pattern = malloc(len); snprintf(pattern, len, "Reference 'refs/remotes/origin/%s' not found", branch); if (strstr(remote, prefs.cloud_git_url) && strstr(msg, pattern)) { /* we're trying to open the remote branch that corresponds * to our cloud storage and the branch doesn't exist. * So we need to create the branch and push it to the remote */ cloned_repo = create_and_push_remote(localdir, remote, branch); } else if (strstr(remote, prefs.cloud_git_url)) { report_error(translate("gettextFromC", "Error connecting to Subsurface cloud storage")); } else { report_error(translate("gettextFromC", "git clone of %s failed (%s)"), remote, msg); } free(pattern); } return cloned_repo; } static struct git_repository *get_remote_repo(const char *localdir, const char *remote, const char *branch) { struct stat st; enum remote_transport rt; /* figure out the remote transport */ if (strncmp(remote, "ssh://", 6) == 0) rt = RT_SSH; else if (strncmp(remote, "https://", 8) == 0) rt = RT_HTTPS; else rt = RT_OTHER; /* Do we already have a local cache? */ if (!stat(localdir, &st)) { if (!S_ISDIR(st.st_mode)) { report_error("local git cache at '%s' is corrupt"); return NULL; } return update_local_repo(localdir, remote, branch, rt); } return create_local_repo(localdir, remote, branch, rt); } /* * This turns a remote repository into a local one if possible. * * The recognized formats are * git://host/repo[branch] * ssh://host/repo[branch] * http://host/repo[branch] * https://host/repo[branch] * file://repo[branch] */ static struct git_repository *is_remote_git_repository(char *remote, const char *branch) { char c, *localdir; const char *p = remote; while ((c = *p++) >= 'a' && c <= 'z') /* nothing */; if (c != ':') return NULL; if (*p++ != '/' || *p++ != '/') return NULL; /* Special-case "file://", since it's already local */ if (!strncmp(remote, "file://", 7)) remote += 7; /* * Ok, we found "[a-z]*://", we've simplified the * local repo case (because libgit2 is insanely slow * for that), and we think we have a real "remote * git" format. * * We now create the SHA1 hash of the whole thing, * including the branch name. That will be our unique * unique local repository name. * * NOTE! We will create a local repository per branch, * because * * (a) libgit2 remote tracking branch support seems to * be a bit lacking * (b) we'll actually check the branch out so that we * can do merges etc too. * * so even if you have a single remote git repo with * multiple branches for different people, the local * caches will sadly force that to split into multiple * individual repositories. */ /* * next we need to make sure that any encoded username * has been extracted from an https:// based URL */ if (!strncmp(remote, "https://", 8)) { char *at = strchr(remote, '@'); if (at) { /* was this the @ that denotes an account? that means it was before the * first '/' after the https:// - so let's find a '/' after that and compare */ char *slash = strchr(remote + 8, '/'); if (slash && slash > at) { /* grab the part between "https://" and "@" as encoded email address * (that's our username) and move the rest of the URL forward, remembering * to copy the closing NUL as well */ prefs.cloud_storage_email_encoded = strndup(remote + 8, at - remote - 8); memmove(remote + 8, at + 1, strlen(at + 1) + 1); } } } localdir = get_local_dir(remote, branch); if (!localdir) return NULL; return get_remote_repo(localdir, remote, branch); } /* * If it's not a git repo, return NULL. Be very conservative. */ struct git_repository *is_git_repository(const char *filename, const char **branchp, const char **remote) { int flen, blen, ret; int offset = 1; struct stat st; git_repository *repo; char *loc, *branch; flen = strlen(filename); if (!flen || filename[--flen] != ']') return NULL; /* Find the matching '[' */ blen = 0; while (flen && filename[--flen] != '[') blen++; /* Ignore slashes at the end of the repo name */ while (flen && filename[flen-1] == '/') { flen--; offset++; } if (!flen) return NULL; /* * This is the "point of no return": the name matches * the git repository name rules, and we will no longer * return NULL. * * We will either return "dummy_git_repository" and the * branch pointer will have the _whole_ filename in it, * or we will return a real git repository with the * branch pointer being filled in with just the branch * name. * * The actual git reading/writing routines can use this * to generate proper error messages. */ *branchp = filename; loc = format_string("%.*s", flen, filename); if (!loc) return dummy_git_repository; branch = format_string("%.*s", blen, filename + flen + offset); if (!branch) { free(loc); return dummy_git_repository; } repo = is_remote_git_repository(loc, branch); if (repo) { if (remote) *remote = loc; else free(loc); *branchp = branch; return repo; } if (stat(loc, &st) < 0 || !S_ISDIR(st.st_mode)) { free(loc); free(branch); return dummy_git_repository; } ret = git_repository_open(&repo, loc); free(loc); if (ret < 0) { free(branch); return dummy_git_repository; } if (remote) *remote = NULL; *branchp = branch; return repo; }