short i/o: fix calls to read to use xread or read_in_full

We have a number of badly checked read() calls.  Often we are
expecting read() to read exactly the size we requested or fail, this
fails to handle interrupts or short reads.  Add a read_in_full()
providing those semantics.  Otherwise we at a minimum need to check
for EINTR and EAGAIN, where this is appropriate use xread().

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/builtin-grep.c b/builtin-grep.c
index 3b1b1cbbfa7bf348c17c025afa217ffff97087e3..2bfbdb71407dcd0ddfe970f6a614158d954cd4c0 100644 (file)
--- a/builtin-grep.c
+++ b/builtin-grep.c
@@ -136,7 +136,7 @@ static int grep_file(struct grep_opt *opt, const char *filename)
        if (i < 0)
                goto err_ret;
        data = xmalloc(st.st_size + 1);
-       if (st.st_size != xread(i, data, st.st_size)) {
+       if (st.st_size != read_in_full(i, data, st.st_size)) {
                error("'%s': short read %s", filename, strerror(errno));
                close(i);
                free(data);

diff --git a/builtin-tar-tree.c b/builtin-tar-tree.c
index 11e62fc141f592977373630c7671d3e7e914c314..ad802fc1aa7fe2b487b2ffdac68f27df82ebc941 100644 (file)
--- a/builtin-tar-tree.c
+++ b/builtin-tar-tree.c
@@ -74,7 +74,7 @@ int cmd_get_tar_commit_id(int argc, const char **argv, const char *prefix)
        char *content = buffer + RECORDSIZE;
        ssize_t n;
 
-       n = xread(0, buffer, HEADERSIZE);
+       n = read_in_full(0, buffer, HEADERSIZE);
        if (n < HEADERSIZE)
                die("git-get-tar-commit-id: read error");
        if (header->typeflag[0] != 'g')

diff --git a/builtin-upload-archive.c b/builtin-upload-archive.c
index e4156f8f48aeed307b1754bada173034dd81a311..48ae09e9b5268ce1f11cfba433680a147ca39f7e 100644 (file)
--- a/builtin-upload-archive.c
+++ b/builtin-upload-archive.c
@@ -91,7 +91,7 @@ static void process_input(int child_fd, int band)
        char buf[16384];
        ssize_t sz = read(child_fd, buf, sizeof(buf));
        if (sz < 0) {
-               if (errno != EINTR)
+               if (errno != EAGAIN && errno != EINTR)
                        error_clnt("read error: %s\n", strerror(errno));
                return;
        }

diff --git a/cache.h b/cache.h
index 38a20a806950752f0449cf244e06149d5d5aca51..a9583ff18eec46bf945ef820ea4a41fe51e0a4b1 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -432,6 +432,7 @@ extern char *git_commit_encoding;
 extern char *git_log_output_encoding;
 
 extern int copy_fd(int ifd, int ofd);
+extern int read_in_full(int fd, void *buf, size_t count);
 extern void read_or_die(int fd, void *buf, size_t count);
 extern int write_in_full(int fd, const void *buf, size_t count);
 extern void write_or_die(int fd, const void *buf, size_t count);

diff --git a/dir.c b/dir.c
index 0338d6c4e0ab4409d6023db96f5298d292692099..32b57f0125d1b9e95345eb23a9a32fbf8444b1b8 100644 (file)
--- a/dir.c
+++ b/dir.c
@@ -142,7 +142,7 @@ static int add_excludes_from_file_1(const char *fname,
                return 0;
        }
        buf = xmalloc(size+1);
-       if (read(fd, buf, size) != size)
+       if (read_in_full(fd, buf, size) != size)
                goto err;
        close(fd);
 

diff --git a/http-fetch.c b/http-fetch.c
index 396552da022a1dca9c43738be4d87c664f31a06c..50a3b005ab65b422d9d02010c75c5ecdc115f034 100644 (file)
--- a/http-fetch.c
+++ b/http-fetch.c
@@ -175,7 +175,7 @@ static void start_object_request(struct object_request *obj_req)
        prevlocal = open(prevfile, O_RDONLY);
        if (prevlocal != -1) {
                do {
-                       prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
+                       prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
                        if (prev_read>0) {
                                if (fwrite_sha1_file(prev_buf,
                                                     1,

diff --git a/http-push.c b/http-push.c
index ecefdfd4f8c9c17282f5cec10640343359278028..acb5c273aaf6fc5527fe0d4b326344064fcfa62e 100644 (file)
--- a/http-push.c
+++ b/http-push.c
@@ -288,7 +288,7 @@ static void start_fetch_loose(struct transfer_request *request)
        prevlocal = open(prevfile, O_RDONLY);
        if (prevlocal != -1) {
                do {
-                       prev_read = read(prevlocal, prev_buf, PREV_BUF_SIZE);
+                       prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
                        if (prev_read>0) {
                                if (fwrite_sha1_file(prev_buf,
                                                     1,

diff --git a/imap-send.c b/imap-send.c
index ad91858bc43d046ea199f5a52c372b2a243c647f..8de19e3cc667dd08db529a874d59614183c8dbb7 100644 (file)
--- a/imap-send.c
+++ b/imap-send.c
@@ -224,7 +224,7 @@ socket_perror( const char *func, Socket_t *sock, int ret )
 static int
 socket_read( Socket_t *sock, char *buf, int len )
 {
-       int n = read( sock->fd, buf, len );
+       int n = xread( sock->fd, buf, len );
        if (n <= 0) {
                socket_perror( "read", sock, n );
                close( sock->fd );
@@ -390,7 +390,7 @@ arc4_init( void )
                fprintf( stderr, "Fatal: no random number source available.\n" );
                exit( 3 );
        }
-       if (read( fd, dat, 128 ) != 128) {
+       if (read_in_full( fd, dat, 128 ) != 128) {
                fprintf( stderr, "Fatal: cannot read random number source.\n" );
                exit( 3 );
        }

diff --git a/index-pack.c b/index-pack.c
index 5f6d128a836f8ed9447f81280ae679e19c9939ff..e9a53032226edd5663458031734c135afb5db0ef 100644 (file)
--- a/index-pack.c
+++ b/index-pack.c
@@ -638,7 +638,7 @@ static void readjust_pack_header_and_sha1(unsigned char *sha1)
        /* Rewrite pack header with updated object number */
        if (lseek(output_fd, 0, SEEK_SET) != 0)
                die("cannot seek back: %s", strerror(errno));
-       if (xread(output_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
+       if (read_in_full(output_fd, &hdr, sizeof(hdr)) != sizeof(hdr))
                die("cannot read pack header back: %s", strerror(errno));
        hdr.hdr_entries = htonl(nr_objects);
        if (lseek(output_fd, 0, SEEK_SET) != 0)

diff --git a/local-fetch.c b/local-fetch.c
index 7b6875cce6c5a08db06e637abc48ce8f26216db4..cf99cb72dd48f65a8c3dd1606b77334f79afab8f 100644 (file)
--- a/local-fetch.c
+++ b/local-fetch.c
@@ -184,7 +184,7 @@ int fetch_ref(char *ref, unsigned char *sha1)
                fprintf(stderr, "cannot open %s\n", filename);
                return -1;
        }
-       if (read(ifd, hex, 40) != 40 || get_sha1_hex(hex, sha1)) {
+       if (read_in_full(ifd, hex, 40) != 40 || get_sha1_hex(hex, sha1)) {
                close(ifd);
                fprintf(stderr, "cannot read from %s\n", filename);
                return -1;

diff --git a/path.c b/path.c
index 066f62195508033a5f72504e4805ea436424296e..bb5ee7bf99780b6c4069dd9833994b24f1577e82 100644 (file)
--- a/path.c
+++ b/path.c
@@ -113,7 +113,7 @@ int validate_symref(const char *path)
        fd = open(path, O_RDONLY);
        if (fd < 0)
                return -1;
-       len = read(fd, buffer, sizeof(buffer)-1);
+       len = read_in_full(fd, buffer, sizeof(buffer)-1);
        close(fd);
 
        /*

diff --git a/refs.c b/refs.c
index 52057455a20cb4641005c9248b5499cca83c77c1..2b69e1eddc01fc87ea18e22960184f57b5590dcc 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -284,7 +284,7 @@ const char *resolve_ref(const char *ref, unsigned char *sha1, int reading, int *
                fd = open(path, O_RDONLY);
                if (fd < 0)
                        return NULL;
-               len = read(fd, buffer, sizeof(buffer)-1);
+               len = read_in_full(fd, buffer, sizeof(buffer)-1);
                close(fd);
 
                /*

diff --git a/sha1_file.c b/sha1_file.c
index d9622d95e7e3d7b91982ae60dbc36a7996856682..0c9483c5c0ddf2e99dd6d1b556ce5cf52c4bab30 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -1869,7 +1869,7 @@ int write_sha1_from_fd(const unsigned char *sha1, int fd, char *buffer,
                        if (ret != Z_OK)
                                break;
                }
-               size = read(fd, buffer + *bufposn, bufsize - *bufposn);
+               size = xread(fd, buffer + *bufposn, bufsize - *bufposn);
                if (size <= 0) {
                        close(local);
                        unlink(tmpfile);

diff --git a/ssh-fetch.c b/ssh-fetch.c
index b006c5c9802d96bc504188e10a9698a1f943477c..72965d678ae4e4b2b2fc64e8979d8a9e1d3d81d0 100644 (file)
--- a/ssh-fetch.c
+++ b/ssh-fetch.c
@@ -82,7 +82,7 @@ int fetch(unsigned char *sha1)
                remote = conn_buf[0];
                memmove(conn_buf, conn_buf + 1, --conn_buf_posn);
        } else {
-               if (read(fd_in, &remote, 1) < 1)
+               if (xread(fd_in, &remote, 1) < 1)
                        return -1;
        }
        /* fprintf(stderr, "Got %d\n", remote); */
@@ -99,7 +99,7 @@ static int get_version(void)
        char type = 'v';
        write(fd_out, &type, 1);
        write(fd_out, &local_version, 1);
-       if (read(fd_in, &remote_version, 1) < 1) {
+       if (xread(fd_in, &remote_version, 1) < 1) {
                return error("Couldn't read version from remote end");
        }
        return 0;
@@ -111,10 +111,13 @@ int fetch_ref(char *ref, unsigned char *sha1)
        char type = 'r';
        write(fd_out, &type, 1);
        write(fd_out, ref, strlen(ref) + 1);
-       read(fd_in, &remote, 1);
+
+       if (read_in_full(fd_in, &remote, 1) != 1)
+               return -1;
        if (remote < 0)
                return remote;
-       read(fd_in, sha1, 20);
+       if (read_in_full(fd_in, sha1, 20) != 20)
+               return -1;
        return 0;
 }
 

diff --git a/ssh-upload.c b/ssh-upload.c
index 901e0366df25f23530e68237eabe59891a5b78d7..86b169bf4fb7712327b72d8e57e25248f9572954 100644 (file)
--- a/ssh-upload.c
+++ b/ssh-upload.c
@@ -21,17 +21,14 @@ static int serve_object(int fd_in, int fd_out) {
        ssize_t size;
        unsigned char sha1[20];
        signed char remote;
-       int posn = 0;
-       do {
-               size = read(fd_in, sha1 + posn, 20 - posn);
-               if (size < 0) {
-                       perror("git-ssh-upload: read ");
-                       return -1;
-               }
-               if (!size)
-                       return -1;
-               posn += size;
-       } while (posn < 20);
+
+       size = read_in_full(fd_in, sha1, 20);
+       if (size < 0) {
+               perror("git-ssh-upload: read ");
+               return -1;
+       }
+       if (!size)
+               return -1;
        
        if (verbose)
                fprintf(stderr, "Serving %s\n", sha1_to_hex(sha1));
@@ -54,7 +51,7 @@ static int serve_object(int fd_in, int fd_out) {
 
 static int serve_version(int fd_in, int fd_out)
 {
-       if (read(fd_in, &remote_version, 1) < 1)
+       if (xread(fd_in, &remote_version, 1) < 1)
                return -1;
        write(fd_out, &local_version, 1);
        return 0;
@@ -67,7 +64,7 @@ static int serve_ref(int fd_in, int fd_out)
        int posn = 0;
        signed char remote = 0;
        do {
-               if (posn >= PATH_MAX || read(fd_in, ref + posn, 1) < 1)
+               if (posn >= PATH_MAX || xread(fd_in, ref + posn, 1) < 1)
                        return -1;
                posn++;
        } while (ref[posn - 1]);
@@ -89,7 +86,7 @@ static void service(int fd_in, int fd_out) {
        char type;
        int retval;
        do {
-               retval = read(fd_in, &type, 1);
+               retval = xread(fd_in, &type, 1);
                if (retval < 1) {
                        if (retval < 0)
                                perror("git-ssh-upload: read ");

diff --git a/upload-pack.c b/upload-pack.c
index c568ef066c9e7e0021468cfe7cb904f40ac477f1..03a4156e19655c1f1d724163d0a712f63fc72c6e 100644 (file)
--- a/upload-pack.c
+++ b/upload-pack.c
@@ -242,7 +242,7 @@ static void create_pack_file(void)
                                        *cp++ = buffered;
                                        outsz++;
                                }
-                               sz = read(pu_pipe[0], cp,
+                               sz = xread(pu_pipe[0], cp,
                                          sizeof(data) - outsz);
                                if (0 < sz)
                                                ;
@@ -267,7 +267,7 @@ static void create_pack_file(void)
                                /* Status ready; we ship that in the side-band
                                 * or dump to the standard error.
                                 */
-                               sz = read(pe_pipe[0], progress,
+                               sz = xread(pe_pipe[0], progress,
                                          sizeof(progress));
                                if (0 < sz)
                                        send_client_data(2, progress, sz);

diff --git a/write_or_die.c b/write_or_die.c
index 613c0c3f6e90cc6a1b7ae9c0ade4e5c10dc25029..e7f82639ffb068dd754855ca464a20721a36c9db 100644 (file)
--- a/write_or_die.c
+++ b/write_or_die.c
@@ -1,19 +1,36 @@
 #include "cache.h"
 
-void read_or_die(int fd, void *buf, size_t count)
+int read_in_full(int fd, void *buf, size_t count)
 {
        char *p = buf;
-       ssize_t loaded;
+       ssize_t total = 0;
+       ssize_t loaded = 0;
 
        while (count > 0) {
                loaded = xread(fd, p, count);
-               if (loaded == 0)
-                       die("unexpected end of file");
-               else if (loaded < 0)
-                       die("read error (%s)", strerror(errno));
+               if (loaded <= 0) {
+                       if (total)
+                               return total;
+                       else
+                               return loaded;
+               }
                count -= loaded;
                p += loaded;
+               total += loaded;
        }
+
+       return total;
+}
+
+void read_or_die(int fd, void *buf, size_t count)
+{
+       ssize_t loaded;
+
+       loaded = read_in_full(fd, buf, count);
+       if (loaded == 0)
+               die("unexpected end of file");
+       else if (loaded < 0)
+               die("read error (%s)", strerror(errno));
 }
 
 void write_or_die(int fd, const void *buf, size_t count)