Andrew's git / gitweb.git / fetch-clone.c
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fetch-clone.con commit gitweb: Secure against commit-ish/tree-ish with the same name as path (45bd0c8)
   1#include "cache.h"
   2#include "exec_cmd.h"
   3#include "pkt-line.h"
   4#include "sideband.h"
   5#include <sys/wait.h>
   6#include <sys/time.h>
   7
   8static int finish_pack(const char *pack_tmp_name, const char *me)
   9{
  10        int pipe_fd[2];
  11        pid_t pid;
  12        char idx[PATH_MAX];
  13        char final[PATH_MAX];
  14        char hash[41];
  15        unsigned char sha1[20];
  16        char *cp;
  17        int err = 0;
  18
  19        if (pipe(pipe_fd) < 0)
  20                die("%s: unable to set up pipe", me);
  21
  22        strcpy(idx, pack_tmp_name); /* ".git/objects/pack-XXXXXX" */
  23        cp = strrchr(idx, '/');
  24        memcpy(cp, "/pidx", 5);
  25
  26        pid = fork();
  27        if (pid < 0)
  28                die("%s: unable to fork off git-index-pack", me);
  29        if (!pid) {
  30                close(0);
  31                dup2(pipe_fd[1], 1);
  32                close(pipe_fd[0]);
  33                close(pipe_fd[1]);
  34                execl_git_cmd("index-pack", "-o", idx, pack_tmp_name, NULL);
  35                error("cannot exec git-index-pack <%s> <%s>",
  36                      idx, pack_tmp_name);
  37                exit(1);
  38        }
  39        close(pipe_fd[1]);
  40        if (read(pipe_fd[0], hash, 40) != 40) {
  41                error("%s: unable to read from git-index-pack", me);
  42                err = 1;
  43        }
  44        close(pipe_fd[0]);
  45
  46        for (;;) {
  47                int status, code;
  48
  49                if (waitpid(pid, &status, 0) < 0) {
  50                        if (errno == EINTR)
  51                                continue;
  52                        error("waitpid failed (%s)", strerror(errno));
  53                        goto error_die;
  54                }
  55                if (WIFSIGNALED(status)) {
  56                        int sig = WTERMSIG(status);
  57                        error("git-index-pack died of signal %d", sig);
  58                        goto error_die;
  59                }
  60                if (!WIFEXITED(status)) {
  61                        error("git-index-pack died of unnatural causes %d",
  62                              status);
  63                        goto error_die;
  64                }
  65                code = WEXITSTATUS(status);
  66                if (code) {
  67                        error("git-index-pack died with error code %d", code);
  68                        goto error_die;
  69                }
  70                if (err)
  71                        goto error_die;
  72                break;
  73        }
  74        hash[40] = 0;
  75        if (get_sha1_hex(hash, sha1)) {
  76                error("git-index-pack reported nonsense '%s'", hash);
  77                goto error_die;
  78        }
  79        /* Now we have pack in pack_tmp_name[], and
  80         * idx in idx[]; rename them to their final names.
  81         */
  82        snprintf(final, sizeof(final),
  83                 "%s/pack/pack-%s.pack", get_object_directory(), hash);
  84        move_temp_to_file(pack_tmp_name, final);
  85        chmod(final, 0444);
  86        snprintf(final, sizeof(final),
  87                 "%s/pack/pack-%s.idx", get_object_directory(), hash);
  88        move_temp_to_file(idx, final);
  89        chmod(final, 0444);
  90        return 0;
  91
  92 error_die:
  93        unlink(idx);
  94        unlink(pack_tmp_name);
  95        exit(1);
  96}
  97
  98static pid_t setup_sideband(int sideband, const char *me, int fd[2], int xd[2])
  99{
 100        pid_t side_pid;
 101
 102        if (!sideband) {
 103                fd[0] = xd[0];
 104                fd[1] = xd[1];
 105                return 0;
 106        }
 107        /* xd[] is talking with upload-pack; subprocess reads from
 108         * xd[0], spits out band#2 to stderr, and feeds us band#1
 109         * through our fd[0].
 110         */
 111        if (pipe(fd) < 0)
 112                die("%s: unable to set up pipe", me);
 113        side_pid = fork();
 114        if (side_pid < 0)
 115                die("%s: unable to fork off sideband demultiplexer", me);
 116        if (!side_pid) {
 117                /* subprocess */
 118                close(fd[0]);
 119                if (xd[0] != xd[1])
 120                        close(xd[1]);
 121                if (recv_sideband(me, xd[0], fd[1], 2))
 122                        exit(1);
 123                exit(0);
 124        }
 125        close(xd[0]);
 126        close(fd[1]);
 127        fd[1] = xd[1];
 128        return side_pid;
 129}
 130
 131int receive_unpack_pack(int xd[2], const char *me, int quiet, int sideband)
 132{
 133        int status;
 134        pid_t pid, side_pid;
 135        int fd[2];
 136
 137        side_pid = setup_sideband(sideband, me, fd, xd);
 138        pid = fork();
 139        if (pid < 0)
 140                die("%s: unable to fork off git-unpack-objects", me);
 141        if (!pid) {
 142                dup2(fd[0], 0);
 143                close(fd[0]);
 144                close(fd[1]);
 145                execl_git_cmd("unpack-objects", quiet ? "-q" : NULL, NULL);
 146                die("git-unpack-objects exec failed");
 147        }
 148        close(fd[0]);
 149        close(fd[1]);
 150        while (waitpid(pid, &status, 0) < 0) {
 151                if (errno != EINTR)
 152                        die("waiting for git-unpack-objects: %s",
 153                            strerror(errno));
 154        }
 155        if (WIFEXITED(status)) {
 156                int code = WEXITSTATUS(status);
 157                if (code)
 158                        die("git-unpack-objects died with error code %d",
 159                            code);
 160                return 0;
 161        }
 162        if (WIFSIGNALED(status)) {
 163                int sig = WTERMSIG(status);
 164                die("git-unpack-objects died of signal %d", sig);
 165        }
 166        die("git-unpack-objects died of unnatural causes %d", status);
 167}
 168
 169/*
 170 * We average out the download speed over this many "events", where
 171 * an event is a minimum of about half a second. That way, we get
 172 * a reasonably stable number.
 173 */
 174#define NR_AVERAGE (4)
 175
 176/*
 177 * A "binary msec" is a power-of-two-msec, aka 1/1024th of a second.
 178 * Keeping the time in that format means that "bytes / msecs" means
 179 * the same as kB/s (modulo rounding).
 180 *
 181 * 1000512 is a magic number (usecs in a second, rounded up by half
 182 * of 1024, to make "rounding" come out right ;)
 183 */
 184#define usec_to_binarymsec(x) ((int)(x) / (1000512 >> 10))
 185
 186int receive_keep_pack(int xd[2], const char *me, int quiet, int sideband)
 187{
 188        char tmpfile[PATH_MAX];
 189        int ofd, ifd, fd[2];
 190        unsigned long total;
 191        static struct timeval prev_tv;
 192        struct average {
 193                unsigned long bytes;
 194                unsigned long time;
 195        } download[NR_AVERAGE] = { {0, 0}, };
 196        unsigned long avg_bytes, avg_time;
 197        int idx = 0;
 198
 199        setup_sideband(sideband, me, fd, xd);
 200
 201        ifd = fd[0];
 202        snprintf(tmpfile, sizeof(tmpfile),
 203                 "%s/pack/tmp-XXXXXX", get_object_directory());
 204        ofd = mkstemp(tmpfile);
 205        if (ofd < 0)
 206                return error("unable to create temporary file %s", tmpfile);
 207
 208        gettimeofday(&prev_tv, NULL);
 209        total = 0;
 210        avg_bytes = 0;
 211        avg_time = 0;
 212        while (1) {
 213                char buf[8192];
 214                ssize_t sz, wsz, pos;
 215                sz = read(ifd, buf, sizeof(buf));
 216                if (sz == 0)
 217                        break;
 218                if (sz < 0) {
 219                        if (errno != EINTR && errno != EAGAIN) {
 220                                error("error reading pack (%s)", strerror(errno));
 221                                close(ofd);
 222                                unlink(tmpfile);
 223                                return -1;
 224                        }
 225                        sz = 0;
 226                }
 227                pos = 0;
 228                while (pos < sz) {
 229                        wsz = write(ofd, buf + pos, sz - pos);
 230                        if (wsz < 0) {
 231                                error("error writing pack (%s)",
 232                                      strerror(errno));
 233                                close(ofd);
 234                                unlink(tmpfile);
 235                                return -1;
 236                        }
 237                        pos += wsz;
 238                }
 239                total += sz;
 240                if (!quiet) {
 241                        static unsigned long last;
 242                        struct timeval tv;
 243                        unsigned long diff = total - last;
 244                        /* not really "msecs", but a power-of-two millisec (1/1024th of a sec) */
 245                        unsigned long msecs;
 246
 247                        gettimeofday(&tv, NULL);
 248                        msecs = tv.tv_sec - prev_tv.tv_sec;
 249                        msecs <<= 10;
 250                        msecs += usec_to_binarymsec(tv.tv_usec - prev_tv.tv_usec);
 251
 252                        if (msecs > 500) {
 253                                prev_tv = tv;
 254                                last = total;
 255
 256                                /* Update averages ..*/
 257                                avg_bytes += diff;
 258                                avg_time += msecs;
 259                                avg_bytes -= download[idx].bytes;
 260                                avg_time -= download[idx].time;
 261                                download[idx].bytes = diff;
 262                                download[idx].time = msecs;
 263                                idx++;
 264                                if (idx >= NR_AVERAGE)
 265                                        idx = 0;
 266
 267                                fprintf(stderr, "%4lu.%03luMB  (%lu kB/s)      \r",
 268                                        total >> 20,
 269                                        1000*((total >> 10) & 1023)>>10,
 270                                        avg_bytes / avg_time );
 271                        }
 272                }
 273        }
 274        close(ofd);
 275        return finish_pack(tmpfile, me);
 276}