From 575f497456e4d4669b3b0095482ba2b86f6d2807 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Wed, 29 Jun 2005 17:52:11 -0700 Subject: [PATCH] Add first cut at "git-receive-pack" It's not working yet, but it's at the point where I want to be able to track my changes. The theory of operation is that this is the "remote" side of a "git push". It can tell us what references the remote side has, receives out reference update commands and a pack-file, and can execute the unpacking command. --- Makefile | 4 +- cache.h | 2 + receive-pack.c | 321 +++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 326 insertions(+), 1 deletion(-) create mode 100644 receive-pack.c diff --git a/Makefile b/Makefile index 2f9e247d8..c21a1a0d2 100644 --- a/Makefile +++ b/Makefile @@ -36,7 +36,8 @@ PROG= git-update-cache git-diff-files git-init-db git-write-tree \ git-diff-helper git-tar-tree git-local-pull git-write-blob \ git-get-tar-commit-id git-apply git-stripspace \ git-cvs2git git-diff-stages git-rev-parse git-patch-id \ - git-pack-objects git-unpack-objects git-verify-pack + git-pack-objects git-unpack-objects git-verify-pack \ + git-receive-pack all: $(PROG) @@ -125,6 +126,7 @@ git-patch-id: patch-id.c git-pack-objects: pack-objects.c git-unpack-objects: unpack-objects.c git-verify-pack: verify-pack.c +git-receive-pack: receive-pack.c git-http-pull: LIBS += -lcurl git-rev-list: LIBS += -lssl diff --git a/cache.h b/cache.h index 9b021d656..4e20455f4 100644 --- a/cache.h +++ b/cache.h @@ -14,6 +14,8 @@ #include #include #include +#include +#include #include SHA1_HEADER #include diff --git a/receive-pack.c b/receive-pack.c new file mode 100644 index 000000000..601388314 --- /dev/null +++ b/receive-pack.c @@ -0,0 +1,321 @@ +#include "cache.h" +#include + +static const char receive_pack_usage[] = "git-receive-pack [--unpack=executable] [heads]"; + +static const char *unpacker = "git-unpack-objects"; + +static 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 1; + } + return 0; +} + +static void safe_write(int fd, const void *buf, unsigned n) +{ + while (n) { + int ret = write(fd, buf, n); + if (ret > 0) { + buf += ret; + n -= ret; + continue; + } + if (!ret) + die("write error (disk full?)"); + if (errno == EAGAIN || errno == EINTR) + continue; + die("write error (%s)", strerror(errno)); + } +} + +/* + * If we buffered things up above (we don't, but we should), + * we'd flush it here + */ +static void flush_safe(int fd) +{ +} + +/* + * Write a packetized stream, where each line is preceded by + * its length (including the header) as a 4-byte hex number. + * A length of 'zero' means end of stream (and a length of 1-3 + * would be an error). + */ +#define hex(a) (hexchar[(a) & 15]) +static void packet_write(const char *fmt, ...) +{ + static char buffer[1000]; + static char hexchar[] = "0123456789abcdef"; + va_list args; + unsigned n; + + va_start(args, fmt); + n = vsnprintf(buffer + 4, sizeof(buffer) - 4, fmt, args); + va_end(args); + if (n >= sizeof(buffer)-4) + die("protocol error: impossibly long line"); + n += 4; + buffer[0] = hex(n >> 12); + buffer[1] = hex(n >> 8); + buffer[2] = hex(n >> 4); + buffer[3] = hex(n); + safe_write(1, buffer, n); +} + +static void show_ref(const char *path, unsigned char *sha1) +{ + packet_write("%s %s\n", sha1_to_hex(sha1), path); +} + +static int read_ref(const char *path, unsigned char *sha1) +{ + int ret = -1; + int fd = open(path, O_RDONLY); + + if (fd >= 0) { + char buffer[60]; + if (read(fd, buffer, sizeof(buffer)) >= 40) + ret = get_sha1_hex(buffer, sha1); + close(fd); + } + return ret; +} + +static void write_head_info(const char *base, int nr, char **match) +{ + DIR *dir = opendir(base); + + if (dir) { + struct dirent *de; + int baselen = strlen(base); + char *path = xmalloc(baselen + 257); + memcpy(path, base, baselen); + + while ((de = readdir(dir)) != NULL) { + char sha1[20]; + struct stat st; + int namelen; + + if (de->d_name[0] == '.') + continue; + namelen = strlen(de->d_name); + if (namelen > 255) + continue; + memcpy(path + baselen, de->d_name, namelen+1); + if (lstat(path, &st) < 0) + continue; + if (S_ISDIR(st.st_mode)) { + path[baselen + namelen] = '/'; + path[baselen + namelen + 1] = 0; + write_head_info(path, nr, match); + continue; + } + if (read_ref(path, sha1) < 0) + continue; + if (nr && !path_match(path, nr, match)) + continue; + show_ref(path, sha1); + } + free(path); + closedir(dir); + } +} + +/* + * This is all pretty stupid, but we use this packetized line + * format to make a streaming format possible without ever + * over-running the read buffers. That way we'll never read + * into what might be the pack data (which should go to another + * process entirely). + * + * The writing side could use stdio, but since the reading + * side can't, we stay with pure read/write interfaces. + */ +static void safe_read(int fd, void *buffer, unsigned size) +{ + int n = 0; + + while (n < size) { + int ret = read(0, buffer + n, size - n); + if (ret < 0) { + if (errno == EINTR || errno == EAGAIN) + continue; + die("read error (%s)", strerror(errno)); + } + if (!ret) + die("unexpected EOF"); + n += ret; + } +} + +static int safe_read_line(char *buffer, unsigned size) +{ + int n, len; + + safe_read(0, buffer, 4); + + len = 0; + for (n = 0; n < 4; n++) { + unsigned char c = buffer[n]; + len <<= 4; + if (c >= '0' && c <= '9') { + len += c - '0'; + continue; + } + if (c >= 'a' && c <= 'f') { + len += c - 'a' + 10; + continue; + } + if (c >= 'A' && c <= 'F') { + len += c - 'A' + 10; + continue; + } + die("protocol error: bad line length character"); + } + if (!len) + return 0; + if (len < 4 || len >= size) + die("protocol error: bad line length %d", len); + safe_read(0, buffer + 4, len - 4); + buffer[len] = 0; + return len; +} + +struct line { + struct line *next; + char data[0]; +}; + +struct line *commands = NULL; + +/* + * This gets called after(if) we've successfully + * unpacked the data payload. + */ +static void execute_commands(void) +{ + struct line *line = commands; + + while (line) { + printf("%s", line->data); + line = line->next; + } +} + +static void read_head_info(void) +{ + struct line **p = &commands; + for (;;) { + static char line[1000]; + int len = safe_read_line(line, sizeof(line)); + struct line *n; + if (!len) + break; + n = xmalloc(sizeof(struct line) + len); + n->next = NULL; + memcpy(n->data, line + 4, len - 3); + *p = n; + p = &n->next; + } +} + +static void unpack(void) +{ + pid_t pid = fork(); + + if (pid < 0) + die("unpack fork failed"); + if (!pid) { + char *const envp[] = { "GIT_DIR=.", NULL }; + execle(unpacker, unpacker, NULL, envp); + die("unpack execute failed"); + } + + for (;;) { + int status, code; + int retval = waitpid(pid, &status, 0); + + if (retval < 0) { + if (errno == EINTR) + continue; + die("waitpid failed (%s)", strerror(retval)); + } + if (retval != pid) + die("waitpid is confused"); + if (WIFSIGNALED(status)) + die("%s died of signal %d", unpacker, WTERMSIG(status)); + if (!WIFEXITED(status)) + die("%s died out of really strange complications", unpacker); + code = WEXITSTATUS(status); + if (code) + die("%s exited with error code %d", unpacker, code); + return; + } +} + +int main(int argc, char **argv) +{ + int i, nr_heads = 0; + const char *dir = NULL; + char **heads = NULL; + + argv++; + for (i = 1; i < argc; i++) { + const char *arg = *argv++; + + if (*arg == '-') { + if (!strncmp(arg, "--unpack=", 9)) { + unpacker = arg+9; + continue; + } + /* Do flag handling here */ + usage(receive_pack_usage); + } + dir = arg; + heads = argv; + nr_heads = argc - i - 1; + break; + } + if (!dir) + usage(receive_pack_usage); + + /* chdir to the directory. If that fails, try appending ".git" */ + if (chdir(dir) < 0) { + static char path[PATH_MAX]; + snprintf(path, sizeof(path), "%s.git", dir); + if (chdir(path) < 0) + die("unable to cd to %s", dir); + } + + /* If we have a ".git" directory, chdir to it */ + chdir(".git"); + + if (access("objects", X_OK) < 0 || access("refs/heads", X_OK) < 0) + die("%s doesn't appear to be a git directory", dir); + write_head_info("refs/", nr_heads, heads); + + /* EOF */ + safe_write(1, "0000", 4); + flush_safe(1); + + read_head_info(); + unpack(); + execute_commands(); + return 0; +} -- 2.30.2