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-rw-r--r--receive-pack.c321
1 files changed, 321 insertions, 0 deletions
diff --git a/receive-pack.c b/receive-pack.c
new file mode 100644
index 0000000000..6013883144
--- /dev/null
+++ b/receive-pack.c
@@ -0,0 +1,321 @@
+#include "cache.h"
+#include <sys/wait.h>
+
+static const char receive_pack_usage[] = "git-receive-pack [--unpack=executable] <git-dir> [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;
+}
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