diff options
Diffstat (limited to 'compat')
| -rw-r--r-- | compat/posix.h | 14 | ||||
| -rw-r--r-- | compat/writev.c | 44 |
2 files changed, 58 insertions, 0 deletions
diff --git a/compat/posix.h b/compat/posix.h index 245386fa4a..3c611d2736 100644 --- a/compat/posix.h +++ b/compat/posix.h @@ -137,6 +137,9 @@ #include <sys/socket.h> #include <sys/ioctl.h> #include <sys/statvfs.h> +#ifndef NO_WRITEV +#include <sys/uio.h> +#endif #include <termios.h> #ifndef NO_SYS_SELECT_H #include <sys/select.h> @@ -323,6 +326,17 @@ int git_lstat(const char *, struct stat *); ssize_t git_pread(int fd, void *buf, size_t count, off_t offset); #endif +#ifdef NO_WRITEV +#define writev git_writev +#define iovec git_iovec +struct git_iovec { + void *iov_base; + size_t iov_len; +}; + +ssize_t git_writev(int fd, const struct iovec *iov, int iovcnt); +#endif + #ifdef NO_SETENV #define setenv gitsetenv int gitsetenv(const char *, const char *, int); diff --git a/compat/writev.c b/compat/writev.c new file mode 100644 index 0000000000..3a94870a2f --- /dev/null +++ b/compat/writev.c @@ -0,0 +1,44 @@ +#include "../git-compat-util.h" +#include "../wrapper.h" + +ssize_t git_writev(int fd, const struct iovec *iov, int iovcnt) +{ + size_t total_written = 0; + size_t sum = 0; + + /* + * According to writev(3p), the syscall shall error with EINVAL in case + * the sum of `iov_len` overflows `ssize_t`. + */ + for (int i = 0; i < iovcnt; i++) { + if (iov[i].iov_len > maximum_signed_value_of_type(ssize_t) || + iov[i].iov_len + sum > maximum_signed_value_of_type(ssize_t)) { + errno = EINVAL; + return -1; + } + + sum += iov[i].iov_len; + } + + for (int i = 0; i < iovcnt; i++) { + const char *bytes = iov[i].iov_base; + size_t iovec_written = 0; + + while (iovec_written < iov[i].iov_len) { + ssize_t bytes_written = xwrite(fd, bytes + iovec_written, + iov[i].iov_len - iovec_written); + if (bytes_written < 0) { + if (total_written) + goto out; + return bytes_written; + } + if (!bytes_written) + goto out; + iovec_written += bytes_written; + total_written += bytes_written; + } + } + +out: + return (ssize_t) total_written; +} |